by Tom Gaylord, The Godfather of Airguns™
Writing as B.B. Pelletier
This report covers:
• The 4 modern smallbore calibers
• The point I’m making
• But how did the calibers we have today come into being?
• Airguns are being developed, too
• Birmingham, England, 1905
This question was asked by blog reader, Joe, many weeks ago. He wondered why the airgun calibers we have today are the sizes they are. This is an open-ended question that will never be fully answered, but maybe I can put a small part of it into perspective for you today.
The 4 modern smallbore calibers
We’ll begin by listing the 4 calibers that are currently on the market in the smallbore category. They are .177 (4.5mm), .20 (5mm), .22 (5.5mm) and .25 (6.35mm). These are the 4 we have today. But as recently as 1948, Crosman offered their CG gallery guns in .21 caliber — shooting a proprietary round lead ball. Before that, up into the 1930s, the Quackenbush company offered pellet guns that were smoothbores in 20-1/2 caliber.
From the left — .177, .20, .22 and .25. All are domed pellets made by Crosman.
The Bullseye Pistol introduced the .12-caliber round ball that lasted from 1923 through several incarnations of Sharpshooter pistols made through the 1980s and also with the Daisy company in their Targeteer pistols, which were made in the 1930s and ’40s. While these pistols mostly used No. 6 lead shotgun shot, Daisy did manufacture copper-plated steel Tiny BBs in .12 caliber for a time.
Daisy made special .118 (.12-caliber) steel BBs for their Targeteer pistols.
The Crosman, Quackenbush and Daisy offerings were designed to limit the supply of ammo to their own companies. What they did, instead, was limit the number of buyers willing to go out on a limb for a gun that shot ammo that was hard to get. Ask someone who owns a gun chambered for Remington 5mm rimfire or Winchester WRF cartridges how easy it is to buy ammo today.
The point I’m making
The point I want to make is that it is very risky to introduce a new airgun caliber. Even for major manufacturers such as Crosman, Gamo, Weihrauch or Hatsan, it would be a huge risk to bring out a new caliber for which there were no pellets. The pellets would have to be made, they would have to be distributed and dealers would have to stock them before the new caliber could be successful. And nobody’s going to do that unless the new caliber offers something the existing calibers don’t already have. The .20-caliber pellet has struggled from 1948, when Sheridan introduced it to the world, until the present day, where it’s in last place among the 4 smallbore calibers. It wasn’t until the powerplants began developing reasonable velocities that the .25 caliber finally took off.
What you may not realize is that lead diabolo pellets are harder to make than many kinds of firearm ammunition. While they appear simpler becauser they are made from one homogeneous material, the precision to which they’re made goes beyond that of the most particular bullet makers. According to Dr. Robert Beeman, the H&N engineers told him that if we want pellets to become any more precise, we’ll have to control them down at the molecular level. And pellets are made by the millions — not in small hundred-thousand-unit batches like precision firearm bullets.
There were some experiments with a .14-caliber pellet several decades ago. Pellets that small offer the advantages of using less materials, which, with the price of lead rising all the time, is important. They also allow smaller powerplants to shoot them at reasonable velocities for things like target practice and plinking. Target shooters want holes in paper, and plinkers want to hit their cans and plastic army men. Neither group cares that much about the size of the pellet. So, why didn’t .14-caliber pellets come to market?
They didn’t because of the overwhelming inertia of the .177/4.5mm pellet. World Cup and Olympic competition is all based on .177 caliber, and the enormous investment in equipment is too large for a newcomer pellet to overcome. All the scoring equipment, targets and guns would have to be changed if this caliber were to change. That isn’t likely to happen, any more than Olympic swimmers are likely to start competing in salt water!
But how did the calibers we have today come into being?
This hasn’t addressed Joe’s question, yet, which is why are the calibers we have the ones they are? Why isn’t there a .27-caliber or a .19-caliber pellet?
To learn about that, we need to go back to about the year 1845. That was when the French inventor Louis N. Flobert employed the brand-new explosive priming compound that was being used in the new percussion firearms to propel a projectile all by itself. He had to use small projectiles because the priming compound didn’t have the power that gunpowder had, so he experimented with very small lead balls — often 6mm (.243 caliber) in diameter. His guns were to be used on indoor shooting galleries and even in homes, so they acquired the generic titles gallery guns and parlor guns. As he developed the guns and cartridges, he eventually put a rim on his cartridges so they could be loaded into firearm breeches and extracted after they were fired. The priming compound was in the rim of the cartridge, which was called a rimfire cartridge.
In 1857, the Smith & Wesson company created a .22-caliber rimfire cartridge that had 4 grains of gunpowder (black powder) in the case with the priming compound. It gave a boost to the projectile’s velocity, so this cartridge was able to shoot a 29-grain conical lead bullet. It was called the .22 rimfire cartridge until 1871, when the introduction of the .22 long cartridge forced manufacturers to add the adjective “short” to its name. The .22 short is considered by many to be the first modern self-contained cartridge.
Airguns are being developed, too
At this same time (1840-1880), smallbore airguns were also being produced. They mostly shot darts; but as time passed, they began to shoot a small conical projectile that had a lead nose and a felt tail — the so-called “felted” slug. Other small projectiles (cat slugs, burred slugs) were also made at this time, but darts and round balls continued to be the most popular airgun ammunition through the end of the 19th century.
In Germany and Switzerland, shooters were taking the parlor guns with their percussion caps and balls in a completely different direction. I’m referring to the zimmerstutzen rifle. These were the 10-meter rifles of the 19th century, capable of accuracy that wasn’t surpassed until the advent of the FWB 150/300 in the 1960s. One curious thing that happened with these zimmerstutzen rifles was the size of the ball was reduced from 6mm and .22 caliber to 4.5mm for increased velocity. Actually, zimmerstutzen rifles came in a rainbow of different calibers, but the most popular ranged from 4.3mm to 4.5mm. Interesting — no? Click here to read an article I wrote about zimmerstutzens.
Zimmerstutzens are still being shot today. RWS supplies many of the over 20 calibers of precision balls.
Birmingham, England, 1905
Up to 1905, most smallbore airguns were weak smoothbores that shot with fair accuracy at very close range. Only the specialized dart guns were accurate beyond about 25 feet. But in that year, the world’s first modern air rifle was created by the Birmingham Small Arms company (BSA) of Birmingham, England. That underlever taploading air rifle, called “H The Lincoln,” was able to shoot accurately out to 50 feet and beyond because it was rifled. Just as the percussion cap revolutionized the world of firearms back in the early 1800s, the BSA air rifle did the same for smallbore airguns in 1905.
I don’t think diabolo pellets existed in 1900, but I know for a fact they were around by 1907. They existed in three sizes — No. 1 (.177/4.5mm), No. 2 (.22/5.5mm) and No. 3 (.25/6.35mm). In the beginning, the No. 2 and No. 3 sizes were the most popular; but by the 1920s, the No. 1 size was starting to emerge.
Ad from the 1907 book, The Complete Air-Gunner, by R.B. Townshend. The slug on the left is a burred slug.
What this means
Joe — the .177-caliber pellet was based on a size of round ball being used by the Germans and Swiss in their zimmerstutzen rifles. The .22 caliber was made popular because of the popularity of the .22 rimfire that, by the start of the 20th century, was as popular as it remains today. And I haven’t got a clue where the .25-caliber pellet came from — except that it was already being used in smoothbore airguns like the Gem-type guns.
The round lead balls morphed into felted slugs and burred slugs and finally into diabolo (wasp-waisted) pellets from about the 1880s through 1910. And the most important thing is that they worked! With a BSA air rifle shooting a diabolo pellet, it was possible to put 5 shots into one inch at 50 feet. And in 1907, author R.B. Townshend was talking about how shooting an air rifle at 50 yards was the equivalent of shooting a firearm at 800 yards. We still talk like that today. Don’t we?
There’s no magic surrounding .177 caliber. But the depth to which it has embedded itself into the world of airguns makes it a tough act to follow — or to recreate. It would be like trying to convince people the internet isn’t the best electronic information environment, and they should all subscribe to something different that’s just been invented.
94 thoughts on “How the airgun calibers of today came to be”
That was a nice history lesson on pellets.
But they didn’t come up with or use those half page long equations to figure out what they wanted to use out of their guns. In other words what would be the mathematically best size. Why did Louis N Flobert choose 6mm. Why didn’t he take it up to .250” or down to .220”.
Didn’t somebody throughout time figure out that the size and shape and weight of a .20 caliber pellet would be better than a .177 or .25 cal. And I just used those sizes as a example. I could of said a .177 was better or the .25 was better. Didn’t they use the decimal numbers close to a standard size to come up with a caliber close to that standard size. Like here we use standard measurements and the other countries use the metric system. Well and the U.S. now also uses the metric system. (all our prints at work for the parts we make are in Metric for probably the last 20 or more years).
It still seems to me that somebody had a reason for the size they chose when this was all evolving through time. Like the popular #1,2 and 3 size pellets. Was there some kind of standard established for the barrel size from tool sizes that were available and the size of the pellet followed that standard? I’m just throwing some thoughts out that I have had in my mind through out time. So don’t take it as I’m making a argument. They are just things I have thought about and never really asked about.
There were standards for firearm bores back then. If I am not mistaken, a .177 is a one bore and a .22 is a two bore. I think if you dig around a bit you can confirm or rebut this.
As far as those half page equations, those were developed to explain what happened and help to replicate what happened.
As to which size is best, it depends on the use.
I have a question for you or anyone else out there that might like to chime in. On my 177 cal 2240 hipac conversion I am wondering which would be a better choice for slowing down the pellets in my gun to stay around the 8 to 900 fps range. Right now in its state of tune it tops out at 984 FPS with 10.5 gr CPs and I was wondering if it would be better to go up in the weight of pellets to say the JSB 13.43gr or change the hammer spring back to the stock lighter hammer spring and readjust it to keep the FPS at a peak of 900 FPS.
I like the tune it has now and get 25 shots between 800 to a top of 984 FPS, but I just feel that it may be more accurate at 900 FPS and below for field target matches since the 10.5 FPS is getting into the transonic range. if you think I should just leave it where it is that is fine also as it is hitting hard and is shooting at an average of 915 FPS with 22.58 FPE at the 984 FPS.
I have not done any sighting in of it as yet so I cannot say how accurate it is at this tune level, but was just wondering what some of the more experienced air gunners thought as I have mainly always shot 22 caliber not 177 so any input would be appreciated.
I would try a heavier pellet before changing anything in the gun itself. When shooting at longer ranges (50yds and greater), I’ve found heavier pellets outperform light ones, as the increased mass allows them to maintain their momentum.
A heavier pellet would be the simplest way to slow them down.
I agree with Desertdweller about the heavier pellet. That’s the way I like to go.
But on the other hand if you went back to the lighter factory spring for the striker the gun would have less vibration and bump when you use the lighter spring. Take and dry fire both of your guns and close your eyes and concentrate on what your trigger hand feels. Hold the gun with a light grip for this experiment.
You will be surprised at how the gun will move side to side and bump forward and back when it fires. The heavier spring you use the more noticeable it will be. I like the lightest spring I can get with a medium weight pellet to get the fps I want. If your going for accuracy every little bit helps. I think a weight on the muzzle end of the barrel helps alot also. It will tame those characteristics that the heavier striker spring will produce.
But first it sounds like you need to shoot them more and start making some notes on your targets and start laying them side by side to compare data. You got to start somewhere. But at least you got them shooting now.
Did you get your nitro piston gun yet or find out whats going on with it?
Gunfun & Desertdweller
I had not really thought about the kick from the hammer spring because I have a very light trigger spring in it so the trigger pull is maybe 2 lbs if that and every surface is highly polished. I was leaning toward the heavier pellet also, but then the lighter spring would be easier on all the other parts of the gun and I would not have to buy more pellets right now.
I am making a muzzle weight right now also as there is one on my 22 now and it does make a differenced in the movement of the gun. I think I am going to swap hammer springs and retune for a high of 900 fps with the 10.5s and that should also give me a little higher shot count also and maybe even a flatter curve as well.
Yea I went to mount my scope last night and the mounts are for weaver rails so I have a set coming from ebay for 7 bucks that fit 11mm dovetails that will be Monday or Tuesday so it will give me some more time to tune with the lighter spring.
I talked to USPS today and they said that the gun was shipped economy on a truck versus by plane so it will probably be here Saturday even though the tracking info said yesterday for a delivery date. So I am still waiting for it. I am going to go to the range tomorrow or this weekend to sight my Hatsan in again and the firepower with the 10.5 CPs and get them done so I know how the tray works with the metalmags and get at least two done and completed.
I will let you know how it goes as I need some shooting time instead of working on them all the time.
The trigger spring and polishing you did will only affect the pull rate of the trigger. It won’t have anything to do with the striker or spring.
Once the trigger is pulled and the sear release’s the striker it doesn’t know anything about what the trigger just did. All the striker knows is that it goes flying forward from the striker spring.
Although a heavier striker spring will give the effect of a harder to release trigger. That’s why the lightest striker spring that you can get away with and your satisfied with the velocity the guns making is the way I go.
And I think your about to have some fun data collecting pretty soon.
Then comes the nitro piston gun. I’m curious to know what you think about it.
I realize the trigger spring does not affect the hammer spring and only is affecting the trigger effort. I just wanted you to know that the trigger was not having very much influence on the guns movement due to trigger pull force and you are right a lighter hammer spring will lessen the trigger pull also. I am planning on putting in the stock spring and tuning with it so I don’t have to buy more pellets as I have 1500 10.5 CPs to use up and then I may think about going to the heavier JSB 13.43gr pellets. If it groups well at 50 yards with the 10.5s and the stock spring and gives me the FPS I want with a higher shot count then it will be left alone.
You are right I have some fun tuning and sighting to get done and it will be tuned by the time my scope mounts arrive so then I can get it sighted in and be ready for the hunter class in November. I am looking forward to the Nationals coming up on October 3rd and 4th, I will be there as a spectator and to gather as much learning and info as possible to help me for my first match.
I just got my tracking number for the Benji titan GP nitro I bought so it is on its way also so I will have two nitro guns to shoot and decide which one I keep and which one I use parts from and then sell. The benji most likely will be sold as it has the thumbhole stock and I don’t know yet if I will like it or not, I don’t like the looks of them but if it fits my hand good and lets me shoot more accurately then it may stay and the venom will go. Just have to wait and see.
Still no buyers on my whisper so it will be listed one or two more times and if it doesn’t sell it will be sent back, I hope it sells so I can make a few dollars, but if it don’t then it don’t.
So when will both nitro guns be there?
And I hope you have some good luck with the Whisper. Either way even if you send it back you will still have some more play money.
I got a tracking number for the Benli and it is bring shipped 2 day priority mail so it shows Saturday as the delivery date, the venom should be here Saturday also so I will have a lot more work and shooting to do so I can decide which one I keep and which on gets the parts swapped with the firepower or I may keep them all. Its just depends how they all shoot and how I like the feel of them.
Saturday will be a busy day because we are getting our back porch painted also so it will be a little bit of a shuffle to let the painter do his work while I do mine with the guns.
It will all work out and I am getting anxious now to get the guns and be able to shoot them without anything but pellets.
Yea I hope I can sell the whisper as I brought the price down to 140 bucks with a buy it now of 155, it was 150 and buy it now of 160. if it does not sell I will lower five more dollars and give it another week or two and see if it sells. If not then it will go back and I will get my refund.
I have seen some mis-spells on the blog but that’s a good one. Bunfun. I know, I know the G is by the B. Ok sorry I will stop now.
And it s nice to have a variety of guns to shoot. That’s what keeps a person on their toes.
And the way you say that rocket spring gun shoots I think I would leave it alone if I had it. Can you believe it. I have 4 air guns in my possession right now that are untouched from the way they came from the factory. The .177 and .25 cal. synthetic stock Marauders, the 54 air king and the HW50s. That’s pretty darn good for me.
And darn them Gamo Whispers any way. Just think when it sells you can stock up on pellets or get another Hawke scope or something. That reminds me what gun do you have the Hawke scope on now. Or do you have it on a gun now.
Sorry about that it was late and I was half asleep at the PC, but I bet you got a good laugh out of it any way.
I have not decided if I am going to change anything in the spring gun yet or not, I will just wait and see how the 2 nitro guns shoot and go from there. You are right that the Firepower shoots so good it really does not need to be tampered with as I already have a GRTIII trigger in it. I should have both nitro guns Saturday so I will make up my mind after I shoot them some.
I have the Hatsan that I have not touched other than adding the moderator and the Firepower that I just put the trigger in, but other than those 2 I have tinkered with all the others at one time or another.
Yea if I can sell the whisper for a little profit I will definitely get more pellets or maybe another Hawke for the 177 match gun. The Hawke scope is on the Hatsan and that is where it will stay because it is just the right scope for the Hatsan due to it being accurate with so many different weight pellets. The half mil dots allow me to be able to hold over or under just the right amount without having to guess between the mil dots as to just how much and I do like the Hawke a lot, but I am mounting that Leupold on the 177 to start with and see how I like the combo mil dot/range finding reticle that it has works out and then decide if I need another Hawke or not. The Leupold is a 30mm tube and has the black reticle plus red or green illumination and some of the field targets are down in hollows with a lot of tree cover so the illuminated reticle may be an asset in that type of situation.
Did you ever decide what you were going to do for a rifled barrel for your newer 760 that I sent you the link to, or are you just going to leave it alone.
Nothing on the 760 right now but at least you gave me some ideas of what to look for if I ever do put a barrel in it.
Wouldn’t that be a cool little sleeper type gun if you took a .25 cal. barrel and made it fit a Crosman 760. I know the brains running wild again. But that would be cool don’t you think.
Yea it would be cool to put a 30 cal barrel in the 760, but I don’t think the valve holds enough air volume to be able to really get a 30 cal pellet moving much more than 450 or maybe 500 fps. You would have to open up the valve quite a bit like I have done on my 2289 to hold a greater volume of air and then pump it up 20 to 25 times at the least to get any decent fps out of it. My 2289 at 25 pumps in 22 will do right at 900 fps and it wears you out pumping it up that many time in a very short time like 5 or 6 shots, plus you have to remember the amount of heat you are putting in the air chamber by pumping it so many times as it is hard on the seals and mine has a delrin flat top piston so it will get hot enough to possibly deform the delrin if it is pumped up that many time repeatedly. You can make a aluminum flat top piston and machine the stock domed aluminum valve face in to a flat top with the piston being adjustable so you set it to fit perfectly tight against the valve right before it is at the fully closed end of the pump stroke as that is what holds the pump arm in its closed position.
My grandsons 177 760 will actually out preform my 2289 in fps for any given number of pumps because the valves are the same internal volume and outside dimensions they just are secured in the pump tubes a little differently. Because the same volume and pressure of air is pushing a smaller and lighter pellet in the 760 than the 2289 it will provide more FPS in the 177 versus the 22, but you already know that a 177 will outperform a 22 with the volume and pressures being the same for each caliber.
If it were me I would get that barrel off ebay if it is still for sale and put it in with the extra length that 760 will surprise you even if you do not make the valve and piston into a flat top design because the added barrel length will allow for more time for the air to push on the pellet. The rifled barrel I put in my g-sons 760 was about 2 inches longer than stock and it really made a big difference in performance and accuracy.
Running out of places to reply. What did I call your break barrel spring gun. A Rocket. It should be Firepower; Right. Although Rocket would be a cool name for a air gun don’t you think.
But you put a trigger in it. Did it improve the accuracy on the gun?
And talking about the 760 and the heat from pumping. That’s why I think it would be cool to try to get one of those RC airplane or car engines. And then take the piston and fit it to a pump gun or even springer. I know the Super Tiger engines use a ring on some of their engines. That would be the piston that I would try to get to work.
Or I wonder if a ring could be found then cut a groove in the the piston/plunger head that the gun already has. That could make the pumping more efficient at the higher amount of pumps. I think we talked about that before though.
It was early this morning when I replied back to you about the 760 and I meant to say 25 caliber, but I think you would still have the same issue with not enough air volume to push the pellet fast enough.
The Firepower did get a GRTIII trigger put in it and it did make it more accurate due to the trigger not having any creep in it, now it is just a very short pull and it releases nice and crisp. That is one reason I bought the Benji Nitro because in the pics I could see it already had a GTRIII trigger in it and the crosman venom that I bought does not so I was going to switch triggers before I sell the Benji. The GRTIII trigger is 35 buck by itself
You know I never thought about a nitro engine piston as a piston in a pumper I just wonder how close the size of a nitro engines piston is to the piston of the 760. I just measured a valve and a flat top piston for the 760/2289 pumpers and the brass valve is .618″ and the delrin piston is .615″ so if they make a nitro engine with a bore of say .620″ giving a couple thousands for clearance for piston to bore clearance it would be pretty easy to make a piston out of some round aluminum stock with a groove in it for the piston ring. The only thing is the ring gap would allow for air to escape past it while pumping. Remember the nitro engine is spinning 20.000 plus rpm so a little leakage past the ring is not going to affect it much versus a piston in the gun moving at basically 0 rpm.
The piston in the 760 is plastic and has a cupped rubber seal on the front of the piston so putting a ring on it would not work. The easiest thing especially for you to do is take the 760 apart to get the valve out and take it to work and machine the domed front part of the valve in front of the o-ring on the valve flat, the take the piston and measure its length and make a piece of aluminum bar stock to the pistons dia and then cut it in to 2 pieces and make a groove in one to fit on the pump arm linkage and make the other to fit a o-ring about .030″ back from one end. then thread the center of both half’s and put together with some all thread rod with a lock nut on the piston side to be able to adjust it for a flush snug fit when the pump arm is closed so it cams over to stay closed after pumping it up. I can send you some pics of the pistons and valves I have for my pumpers if you want so you can get a visual image of what you need to make for the newer 760. I believe if you look at your old 760 it has a flat top valve and a flat faced piston that is similar to what I described only it has a hard plastic cup on the piston instead of an o-ring.
I forgot to tell you that I just got done making a barrel weight/ flash suppressor for the 177 from a motorcycle foot peg that is a brushed piece of aluminum 4 inches long and 1 inch in dia. It has a bunch of 1/4 ” holes drilled around the dia to make it look like a flash suppressor and all I had to do was cut of the part that attaches it to a motorcycle and drill a 7/16 hole in it for the barrel and the a hole for the set screw to hold it to the barrel. It looks cool and adds about 6 ounces to the front of the gun and makes it feel more balanced.
I did not get to do any tuning today as it was raining so it was a shop day for making parts. It is supposed to be clear tomorrow so I am going to tune it then and should have both my springer’s tomorrow also.
Another benefit of going with the lighter spring is you have several different brands of pellets in the 10 to 11 grain range to choose from, including Baracuda’s that you can get in 3 different head sizes. Any of these will give similar ballistic results to the CP heavies, and you might find something more accurate.
Thanks I never even considered that point in the equation as I am just so used to CPs being so good in most of my guns that I never really thought about other brand pellets in the same weight category and I am still learning a lot about PCP guns. That’s what makes it fun though is there are so many choices that there is always room to improve with and learn new variables that we sometimes get stuck with one thing and loose sight of what is available.
I will try some different pellet brands when I get it tuned to the range I want it to shoot in as I would like to be between 8 to 900 FPS and get at least 25 shots. That’s where I was with the heavier spring with 25 shots at a high of 984 and a low of 816 FPS, if I can lower the high closer to 900 and keep the low at 800 with more shots I will be happy.
Buldawg, If you’re shooting steel targets 22fpe is likely to be too much power, a heavier pellet will probably raise it again. Have you checked to see what their max power limit is yet?
The power limit is 20 FPE, but the club president said they don’t adhere that strictly to that limit as they are his targets and he said I can go out there whenever I want and shoot with my Hatsan or any other gun and shoot them. My Hatsan makes over 30 FPE with the H&N 12.6 gr field targets and he said it was ok to shoot them with my 25 gr rabbit magnums that make 43 FPE. They may be a little stricter in an actual match though as I have not competed in one yet so I am not sure. That is one reason I want to get the high down to the 900 FPS range, but also to keep the pellets from getting into the transonic range as well as get a higher shot count with less spread between the high and low for a flatter curve.
B.B., off subject, I was looking on the Umarex web site and came across a neat rifle, the Browning Gold Synthetic .177 cal rifle. BUT, this one has 490 fps in the title! Have you heard of this one? Like the 1000 fps Browning Gold, but for smaller frames and easier cocking effort. Just thought it was neat. Thank You, Bradly
There is also a Browning Leverage with the same deal going on. 490 fps.
Those air rifles are made for Canada.
Great article about pellets and their history.
Now, at the end of the article, it says “This entry was posted in Articles, Pellets and tagged airguns, BBs, calibers, Pellets.”
As I newbie to this blog, I would like to know how to find a list of Articles.
Also, how do we find articles tagged with various subjects, such as “airguns, BBs, calibers, Pellets”?
Tags are greatly over-rated! However, you can simply click those tags — they’re links to other blogs that have the same tags.
Thank you, Edith. Now, how do I search for a list of Articles?
Navigating this board is not self evident.
Do you see the navigation column on the right side of the blog page? If not, then widen your browser window til it appears there. If it’s not there, it’s shot to the bottom of the page because your browser window is too narrow to accommodate it.
That navigation column has 2 gun ads and then sections for Recent posts, Categories and Archives. Archives is the section that has all the blog posts listed for every month since March 2005, which is when the blog started.
Glad you made it Aubrey!
I have read this material before but it’s been a while. My 392 prefers .22 balls above any other projectile tested in it so far.
Another fascinating article – I have been curious about how they came up with .177; 22 and .25 for a long time.
We can actually thank a bad business decision on the part of Lincoln Jefferies for the modern air rifle of today. He invented and patented his air rifle in 1904 and started manufacturing them himself. In 1905 he made a deal to allow BSA to also manufacture them. In 1906 alone, BSA made over 10,000 of his air rifles and ended up driving Lincoln Jefferies out of business and BSA has been building air rifles up until the present day. Hopefully, they will not follow Webley and the doe doe bird.
I want to ask you some questions about the FWB 300 but I’m running out of time. Got to get going to work. I will try to reply later.
Doesn’t the 300 use some type of recoil system like the Diana 54 air king?
It is 6 or 7 fpe sidelever gun with a real light cocking effort also if I remember right.
I bet it would have problems trying to shoot out to 50 yards. But maybe if I kept it at 30 to 35 yards it should be a good gun to teach the kids bench resting I would think.
Tell me if I’m missing something about the gun.
You are spot on about this rifle. It is a 10 meter rifle, but does pretty good out to 25 yards. 50 yards is really too far to hope for any real good groups. At that range you pull the trigger, count to 10 and hear the pellet slap the target.
The trigger on these things are incredible. You can adjust it to any way you want it to be, except maybe a heavy, creepy pull.
I am hoping to fool with them some this weekend. I have one of them together, but I think I might go back in and fiddle with it some more. The other one is a pile of parts waiting for a little TLC.
These things are not pretty, but they sure are nice.
The way I picture the 300 is that its kind of a scaled down 54 air king if I dare to say. Side levers are cool.
Does it have the rear peep sight on it still? I was thinking a little bug buster scope would be a neat little scope for it. It would be a little easier to keep the scope rings closer together and that way the front objective won’t overhang the loading position.
When your through messing with it give me a holler. I think it will work for me if I’m right about the scope position.
Let me know what’s up if and when your ready to sell.
B.B. This should be in Shotgun News, American Rifleman, Rifle, Guns and Ammo, Guns, Handloader ( eh ? ),
etc, et al…Outstanding ! I do not use FaceBook, Twitter..wish there were an Email Icon somewhere, like at PA…
has on each item page ..
Thank you ,again…The first mug of Extra Dark Roast Coffee was enjoyed more this morning !
Excellent report, thanks.
While I read this I was reminded of an online poll I took perhaps six or seven years ago. It was a single question: Would you be interested in an airgun caliber smalller than .177?
I was not the only airgunner who had fielded this automated question (probably prompted by an online airgun/ammo purchase). On several forums the reaction was disbelief. Folks simply could not fathom why anyone would bother to consider it.
Obviously the idea went nowhere, but I, too, was never able to make sense of it.
I think I have mentioned in the past that we have a 6mm pellet size in Brazil. It has only been recently introduced, and it is entirely based on our own legal restrictions on airguns larger than 6mm. Yes, “bigbore” airguns of .25 caliber and up are considered “restricted” and subject to more or less the same paperwork than firearms do.
The number “6mm” wasn’t just a coincidence: back in the 1990’s when the very first airsoft spring pistols came into Brazil, we had a surge in armed robbery using these replicas. Authorities did what they excel at, and prohibited them. It took many years of negotiations to change that, and only in the early 2000’s all airguns and airsoft up to 6mm were finally officially considered unrestricted for sale in Brazil.
This left the .25 caliber off-limits, and many shooters wanted more power from their airguns. Someone in CBC/Magtech realized that the difference between .22 and .25 was enough for a split, and came up with the idea of a 6mm/.24 caliber pellet size. A powerful gas ram break-barrel was introduced to fire this caliber, which, as long as I know, remains a proprietary size of CBC/Magtech.
We certainly discuss a lot over here if one day the world will ever be firing 6mm/.24 caliber pellets. Personally, I don’t see the need for it (but I don’t see the need for the .20 either).
Thank you for your comment. That is information I don’t have access to, and it is important to note. Someday we may see a 6mm pellet rifle rising from all this!
Now I know where the British got the idea for their famous football club Aston Villa.
Likely the other way around. The club was formed around 1870s; 30 years before that pellet advert.
I read, and much enjoyed your article on Zimmerstutzens. It was a great read.
The Quackenbush .458 arrived yesterday. It is an experience.
I had another great experience looking after a family’s two young boys for the day. We arrowed apples in the pasture with a youth bow, and popped balloons with an R7. What fun. The boys were so excited. The R7 was a great rifle for them to shoot, and I would not have discovered it (or the Quackenbush) had it not been for this blog.
You are describing what airguns are all about. Congratulations!
I am currently testing some new bullets for the Quackenbush .458, so I may have some things for you in the future.
Thanks for the article. Since big bore firearms are popular and airgunners are always looking for big bore airguns to take out medium and even large games, why didn’t we have large caliber diabolo pellets such as .357, .45 cal…etc?
diabolo pellets would solved the loading problem as you discussed a few articles ago.
Actually, such things do exist as shotgun slugs. I will be writing about big bore bullet design soon and in that report I will mention the French Balle Blondeau slug that has revolutionized shotgun slugs.
Big bore maker Gary Barnes copied it after seeing smoothbore airguns outshoot rifles with these slugs at a big bore match, and he got phenomenal groups out to 200 yards.
Don’t expect such things from Crosman, though. They don’t study ballistics history.
Thank you, thank you, and thank you. I look forward to your article.
Any chance you can also cover how easy/difficult a regular shotgun slug feeds into an airgun breech?
The answer to how easily these bullets feed into the breech is — it varies. With the Quackenbush .458 every .458 bullet up to 405 grains feeds easily. After that the bullet’s nose starts engaging the rifling before the bolt is closed and it becomes very difficult to load those bullets.
I have shot a .458 big bore that feeds easier than pouring mercury down a funnel, but the gun isn’t on the market yet. I will write about it in January, when it come to market.
The Korean big bores vary in the ease of loading. The ones that have a sliding cover at the breech feed easily, but the ones that have bolts actions can be challenging to load.
The Benjamin Rogue was very easy to load, but the magazine limited it to certain bullet lengths and shapes.
I read your articles about the Benjamin Rogue ePCP with great interest. Since this gun was based on Mr. Sikes’s design patent, I took the time to locate this patent in the USPTO website (patent #20130104868). I wasn’t around when the Rogue ePCP came out, I didn’t get the chance to own such as great airgun as claimed in Mr. Sikes’s patent, and I am sure Crosman made some improvements to his original design, and thus it is even better.
Since you have experience with the Rogue ePCP could you please tell me if the claims Mr. Sikes claimed in his patents are true?
(1) In patent claim #3, it said the gun can deliver up to 2500 ft-Lbs of energy. Can the Rogue ePCP deliver this energy, even if it is for only one shot?
(2) In patent claim #8, it said gun can maintain a constant muzzle velocity throughout a range of reservoir gas pressure from approximately 300 psi to 3500 psi, and throughout a range of projectile weights of from approximately 10 grains to 1200 grains. Wow! Is this true?
I regret that I miss the opportunity to buy such a great airgun, at $1300 the ePCP is worth every penny and more.
I can’t tell you if those patent claims are true or not. But often patents are filled with broader claims, just in case the designers should achieve them later on.
I worked with Lloyd on thew Rogue project in the beginning. In fact, I was the one who introduced him to Crosman, and we both went to New York to pitch the idea to them. But then I got sick and was in the hospital while the gun was being developed. Crosman took the basic valve design Lloyd presented, but the4y did not implement our ideas for the gun. The gun we presented was never made. They chose to develop an electronic-looking AR-looking airgun.
I am sad to hear that you got hospitalized. It would indeed be a better airgun if you took part in the design.
Crosman told me that they license Mr. Sikes design. The heart of the PCP is his valve and his electronic that controls it and thus I was hoping that it did achieve at least, a couple of the claims that Mr. Sikes pitched. It would be nice for the big bore airgun hunters if that Rogue can have close to 20 shots per fill as was initially claimed. As for me, I was hoping for an airgun that maintain a constant muzzle velocity. So far I have not found one. If that Rogue can achieve JUST this one goal, I would of pay twice the asking price ($1300 x 2 = $2600) !
Joe, no offense, your chasing a white stag, a unicorn, a Pegasus, a dream. It can’t be done, between gun and pellet, the variables alone… Even the best pcps or epcps regulated or not have an almost constant velocity change shot to shot. There is no such thing as perfection only what you can live with. Trying to create perfect has driven people completely insane throughout human history. Sorry my .02
Thanks Ricka, maybe you are right. Accuracy has multiple variables, and indeed is very difficult to solve. Another variable is being picky of ammo. So far, all the airguns I know only shoots one or a few ammo well. It seems like the higher power an airgun is, the more picky it is with ammo, not just how you shoot it or hold it. I don’t mind the gun being ammo picky, but more importantly, I want the gun to maintain close to constant muzzle velocity when temperature or pressure changes. Even the expensive HW100 FSB that I purchased from Pyramyd Air cannot maintain close to constant velocity when temperature changes.
So far no one can tell me if that Benjamin Rogue ePCP can achieve some of the claims that inventor Mr. Lloyd Sikes stated in his design and patent. I just spoke to Crosman Customers Service about their discontinued Rogue ePCP. I ask him specifically if the Rogue can MAINTAIN a constant muzzle velocity especially when pressure or temperature changes. I have NOT found such an airgun yet. He said that the gun cannot EVEN maintain a constant muzzle velocity from one shot to the next.
I guess I have to really get to know my PCP airgun and learn how it behaves when temperature change during competition so that I can compensate for the shots landing high and low. My hope was high on the Rogue, now I crashed landed. : (
This is a very interesting article today and captivated me last night at 2 in the morning when I first read it. Then when I clicked on the link about the zimmers it just made my head spin with the wealth of info that you researched and recorded to satisfy your own curiosity and desires.
Then the years you relentlessly searched for one to call your own and finally finding one must have been a huge accomplishment in your life and filled a void that had been eating at you for years. I can only be amazed at the entire depth of all the people that at one point or another in time had a hand in developing and refining the calibers of pellets we now enjoy today.
Very Very interesting article for sure and thank you for all your tireless dedication to all thing air gun related.
Thanks BB. That was an excellent article; well researched and written engagingly. I have been reading your blog for years and I really appreciate the research you put in for these little gems of articles. Have you ever thought of curating these articles and publishing them? I am sure a lot of airgun enthusiasts would love to read them over and over again. If you ever publish– perhaps Pyramyd Air can– you will find enthusiastic buyers for such a book.
Thanks for letting me start my day with this.
I have a question/suggestion about the blog lay out when using a cell phone.
Right now you have to scroll to the bottom of the page to get to the recent posts and categories. its not on a sidebar like when I use my laptop which is easier to access for me any way.
Could the cell phone page layout be made so the recent posts and categories is at the top of the page. That way when you log on to the page it will be right at the top and then you could decide where you want to navigate to.
Just a suggestion. I don’t know if would be better that way but I don’t like scrolling up and down on my cell phone.
They deliberately made the right-hand navigation jump to the bottom of the page because most people come to the blog to read the current day’s post. If we put a bunch of stuff (and the RH column is quite large) in their way and made them scroll, scroll, scroll just to read the very thing they came here to read, we would be discouraging people from accessing the blog on mobile devices.
Maybe break it up and put the recent posts on top, then the daily blog and then the categories at the bottom.
If you had the recent posts on top including today’s blog listed there then you could click and go right to what you want or scroll down to that days blog.
We believe most people come here to read the daily blog posts. I honestly cannot think of one blog that I read where the comments would displace the daily posts to a secondary position. Can you direct me a popular blog (on any subject) that puts the comments ahead of the blog posts?
I know what you mean but maybe I didn’t explain right.
I meant to have the recent posts at the top of the page. Then have to days blog at the top of that list. It would be the first thing on the list you see.
Either way it don’t matter at least we can find what we are looking for one way or the other. Thanks.
The change that’s going to be implemented tomorrow morning will end up with 7 blogs on the home page, but each blog will have an excerpt. To read any complete blog, you’ll have to click a READ MORE button under each excerpt. See if that works better for you on your cell phone once it’s up & running. I think it will.
OK thanks Edith. I will check it out tomorrow.
Crosman 1077 – Can I remove the CO2 cartridge after a few shots and then put it back in?
I fired a few (8-10) test shots with my new 1077. Should I leave the CO2 cartridge in the gun and use it in a few days?
If not, if I remove the cartridge, will I be able to insert it again later?
No, you can’t. Once the cartridge is pierced, it has to be used in the gun. Removing it will empty it of gas.
OK. Thanks. But, my user’s manual says to not leave CO2 cartridges in the gun. ???
Color me confused.
The advice in your manual to not leave a CO2 cartridge in your gun was added by the corporate lawyer team. Minimize potential liability to the manufacturer from us stupid consumers.
Don’t worry about leaving a CO2 cartridge in your gun. Just remember when you replace the CO2 cartridge to put a drop of pellgunoil on the cap before installing it in your gun.
Great blog, lots of info. I am now off to design a new caliber!
Good Day Airgunners
Thanks for the timely, and most informative blog on the history of the four popular pellet calibers. I can think of nowhere else you can find such a concise article with so much pertinent information. Chock another win to BB’s blog.
In the past year, I have converted 2 rifles, and one pistol to the .20 cal format after listening to your conversations with Dr. Beeman. He seems to have been one of the last true champions of this almost forgotten caliber. I have gotten more then a few quizzical looks from exponents of .177, or .22. It seems they had never heard of the .20 cal format. For me, the verdict is still out concerning accuracy over the .177, however it does pack a punch on pests similar to the .22.
I haven’t had too much time for shooting the past two weeks as it is the start of harvest time north of the 49th parallel. This past week it almost seems our canner has been going from dusk till dawn preserving the bumper crop of tomatoes thanks to a near perfect summer. Next job will be peeling, coring, and slicing our apples to put in the food dehydrator. All this work pays off come winter, when you have true organic ingredients for spaghetti sauce, chili, and soups, etc. It is a lot of work mind you, and defiantly a labor of love. All that being said, I think I will spend the rest of the afternoon shooting my HW77 on my 25 meter outdoor range. The old adage of all work and no play seems very appealing at the moment. 😉
Ain’t nothing like a hard days work. And to top it off with some good shooting.
Hope you had fun. I’m pretty sure that will be the way it goes for me tomorrow. Well I hope the shooting part anyway. 🙂
Fascinating. The .177 and .22 calibers are fixtures, and we don’t think why. At least for firearms, performance remains a big factor. And you can still trace the evolution from larger, slower projectiles to smaller, faster ones. That even goes on with rimfire where a souped up .17 magnum is competing with the venerable .22 LR. If there is any ballistic ideal, it seems to be the 6mm caliber used by benchrest shooters. But even this is trumped by various applications.
One counterexample to the inertia problem is how Savage seems to no longer be chambering rifles for .223 Remington but is instead using more exotic calibers like the .204 Ruger. I can’t imagine why, but I’m glad I got my .223 when I did.
For airguns, on the other hand, performance seems to play a smaller role. I expect our main calibers will be with us for awhile.
Gunfun1, good question about how to find a good M1. For absolute certainty you almost need to be a collector and personally inspect the gun. But there are a lot of simplifying factors which will give you pretty good assurance of what you’re getting. The Civilian Marksmanship Program (CMP) is the main dispenser of surplus M1s. They have a good reputation, and they grade their rifles into four or so categories: rack, field, service, special, collector. You can read the definitions of these grades on their site. Should you have a chance to inspect a rifle, the main criteria for wear is Muzzle Wear (MW) and Throat Erosion (TE). Muzzle wear is like the name implies. Throat erosion refers to the region connecting the chamber to the barrel. It is apparently subject to the most abuse from the discharging cartridge and wears away faster than other parts. In older rifles, the wear is such that the bullet loses contact and jumps from chamber to barrel which degrades accuracy. There are tools for measuring these two qualities and information on what the values mean. I think someone on the blog picked up a rifle with 0 throat erosion which sounds like it was unused. TE of 2 or 3 are still considered low I think. Other than these qualities, you look for external wear on the wood and metal.
I do believe that all the M1s accepted for service met a high standard. Incidentally, the accuracy requirement, I believe, was to keep a clip of eight shots inside of four inches. That is probably around 3MOA with five shots. Otherwise, there are slight differences between makers that you can be aware of without making absolute decisions. I believe that Harrington & Richardson models from the typewriter company were supposed to be especially good. Winchesters, ironically, are supposed to be relatively poor. I went with the government’s Springfield Armory because for better or worse, they were kind of the ultimate bureaucracy and their standards were very rigid and exacting. I’ve even heard that when the Armory was closed, its machinery was sold off and used to make the high quality barrels of the Krieger Company, but my information has not been verified.
In addition to the CMP, there are also good dealers of M1s. If interested, you can email me at
This is something I would rather not pursue on the PA blog. Finally, regardless of dealer, you want to get your M1 checked by a competent gunsmith since none of the dealers I know test functionality.
Well, to be fair — the .17HMR is a necked down .22WMR… The direct challenger for the .22LR would be the .17HM2.
Possibly a liability issue… .223Rem and 5.56(NATO) are interchangeable in terms of physical design — but the standard loads, and the guns for them, have enough differences to make swapping them less than perfect (overpressure in one direction, excess gas wear in the other; whereas, while 7.62NATO may have stricter quality measures for functioning, the barrels are fully compatible with .308Win).
Thanks for all the info.
And it will be a while before I can really put the money out for one right at the moment.
I did save your email address and I will contact you when I’m ready to start looking for a Garand. I do appreciate that. Thanks.
I think it’s sad nobody likes .20cal and it’s slowly going away, I’m going on a year with my first .20 and I think the pellet size is great. I have noticed the lack of manufacture and supply, Crosman discontinued the Premier dome which every .20 gun seems to shoot excellent, and the new Benjamin .20 shoots horribly from my rifle.
I think every caliber has it’s place but I don’t spend the money to make them… And the pellet debates will go on…
Based upon the local stores — at least as easy as finding .22LR
New Topic: BBs vs. Pellets
I would like to know what BBs and pellets each do best. Specifically, things like accuracy, and suggestions for target shooting, small game (squirrels), and plinking.
I would like suggestions regarding this for both pistols and rifles.
BBs aren’t useful for anything but fun unless you have an accurate gun such as the Avanti Champion 499.
It doesn’t work that way. That’s like asking which brand of gasoline will give you the most miles per gallon without stating which vehicle it will be used in.
Start with the airgun. Then list the caliber. Then we can talk about which pellets to try.
And there are no guarantees, either. Sometimes a gun will use a pellet is isn’t “supposed” to.
You are starting at the beginning. So why not concentrate on one thing before moving to all the others. I would suggest you focus of learning to shoot accurately, because until you can do that, the other things, like hunting, don’t work.
And comparing pistols to rifles is like comparing baseball to football. Both are sports that use a ball, but beyond that, they are different. Each takes a lot of learning. I suggest starting with rifles, because they are the easiest to learn.
Thank you Edith and B.B. As for B.B.’s comments, I do know how to shoot. I have a Texas CHL. I have a couple of handguns, but I have to use them at a shooting range. I would like to shoot my airgun(s) in my 2.5 acre backyard. I just bought a Crosman 1077 pellet rifle, which I like. I am considering a pistol and simply wanted to ask if BBs or pellets are best for such things as target shooting, plinking, and shooting an occasional squirrel that messes with our bird feeder. I don’t want to kill the squirrel, but I want to scare him. Capesh?
NO, NO, NO!
Do NOT shoot a BB gun or pellet gun at an animal to “scare” him. BBs will break the skin of small animals and cause festering wounds. Either kill them or do something else. Airguns will kill — slow or fast, they will kill.
Edith suggested the world’s most accurate BB gun already — the Daisy 499. You can put 10 shots into a group the size of Roosevelt’s head on a dime offhand at 5 meters. No other BB gun in the world can come close to that.
For target shooting (I am a competitive air pistol target shooter) you could do a lot worse than a Beeman P17 single stroke pneumatic. It will hold all its shots on a nickle at 10 meters if you are able. This is shooting one-handed, because target shooting is never 2-handed except in very informal matches.
B.B., I resent your patronizing comments, such as “It doesn’t work that way. That’s like asking which brand of gasoline will give you the most miles per gallon without stating which vehicle it will be used in” and “NO! NO! NO!”
I am not a child or a teen. I am a senior adult and would appreciate being treated as an adult. You can find tactful ways to present your answers.
Edith, you may remove this reply if you wish, but it needed to be said.
Aubrey, if I can help, BBC guns are good for target practice only and you should always make sure of what your shooting at because they WILL ricochet badly and do damage to something. If you want a bb pistol look around Pyramyd’s website and check stuff out,read some reviews, and ask people about something that sounds interesting to you, people will gladly oblige. B.B. is right though in that bb’s cause small wounds that kill slowly and that’s no good for anyone. If your going to hurt them than kill them humanely with a gun powerful enough. That’s what i do or spray then with the hose, that makes for some fun mind games with them. If I were you I would get comfortable with the 1077 first, I just bought one and am really enjoying it for some fun plinking after work. In the meantime you can check out other guns and figure out where to go from there. Maybe a different Co2 or low/medium power springer or if you have some money to invest a pcp and pump. Their are so many options, just ask, and read read read, the internet can be a useful tool Sir.
I am not patronizing you. I am scolding you! If you have a Texas Concealed Handgun License you learned the first rule of gun safety is to NEVER point a gun at something you don’t want to destroy. Shooting animals with airguns as a means of disciplining them violates that rule.
The reason I thought you were a youngster just starting out in shooting is because of comments like that. I didn’t expect to hear that from a trained shooter.
This blog exists to train shooters about airguns. I can forgive a lot of mistakes, but I can’t forgive cruelty to animals.
You are welcome to stay with us and learn about airguns, although I understand if you no longer wish to, and I am sorry if that is the case.
When it comes to safety or responsible conduct with any kind of gun — air or firearm — I will speak my mind. Airguns should be treated the same as firearms, and that means following the rules.
H-m-m-m. I didn’t realize that today’s airguns were so powerful. A far cry from the BB guns I used as a child.
The BB guns from the days of yore shot out plenty of kids’ eyes. Enough, at least, that mothers constantly admonished their children about that danger.
Don’t point a gun at anything you don’t want to destroy. In our house, even airsoft guns shooting a pathetic 200 fps are not pointed any living thing. Once you internalize that mindset, you’re good to go with any gun 😛
I didn’t ever shoot a gun, BB or otherwise, at anyone. My point simply was, as a kid, I saw other kids shooting at each other with their BB guns. Apparently, a hit “smarted” but didn’t do damage.
I think we have ended this discussion.
It could do a lot more than just “smart”. Even a low-powered BB gun like the Daisy 105 Buck (or venerable Red Ryder) has enough energy (.8 to 1.5 ft-lbs muzzle energy) to put a kids eye out. And at close range it can break the skin. The fact that kids used to shoot each other with BB guns didn’t mean BB guns were harmless. It just means that (then as now) kids sometimes do really, really, really dumb stuff.
As for how powerful modern air-rifles can be… Your Crosman 1077 probably produces 5.5 ft-lbs of muzzle energy. I’ll concede that isn’t much compared to the .22 Short’s 75 ft-lbs muzzle energy. However its 4-5 times as powerful as the BB guns you remember. And you also need to remember there are modern airguns that can rival the power of a .22 short… So the old image of airguns as the low-powered BB guns of yore is no longer accurate.
Even the top end AirSoft guns can draw blood — even the $35 spring pistols can cause bruising, and AirSoft shoot 6mm plastic balls that are so large and slow one can often see them on the way to the target. Skirmishers wear heavy clothing (denim at the least, to prevent penetration) and face-masks/goggles to avoid eye/nose/mouth damage. Granted, the $35 pistol is likely not going to penetrate some thick furred critter — but my AEG M14 has been known to punch through two layers of paper bag and puncture a glass basement window (wasn’t me — my father hung up the bag and did the shooting; found the window broken a day later). They’ll easily penetrate a cardboard box.
The behavior you describe has never been considered “safe” or proper.
You’re beating a dead horse! What part of “I think we have ended this discussion.” (see above) do you not understand?
Please note that, by the indentation, I was responding to the post that occurs ABOVE your “ended this discussion”.
I read via an RSS feed, which orders the posts by time of entry.
Very informative article that has filled in some of the many gaps in my knowledge. Three points occur to me: (1) Calibres smaller than 4.5mm would suffer handling problems. It would be fiddly to load a 4mm pellet using adult-sized fingers at the best of times, let alone on a cold day out in the field or at an unheated range. Some hunters in Britain favour .22 for that reason alone. (2) .22 calibre has benefitted from so many manufacturers being set up to make .22 rimfire barrels. The barrel on my BSA Airsporter seems to have been made on the same machinery as the barrel on my 1950’s BSA Supersport 5 rimfire. It’s believed that BSA and Webley made ten .22 airguns for every .177 airgun. I think ease of manufacture was part of that reason. Finally (3) I think in British termminology no.2 bore is 5.6mm rather than 5.5mm. Continental Europeans seem to make their .22 barrels in 5.5mm whilst we English made ours in 5.6mm. It often makes a difference when using British pellets in a German gun and vice-versa. Terrific article. Wish we could still own M1 Garands in the UK!
I don’t know if this is relevant to the caliber discussion, but I’ve always heard that the calibers of the early rimfires (like the Flobert) owed at least something to the size of percussion/musket caps. Of course I could be completely wrong about that.