by B.B. Pelletier
This question came from someone I nicknamed RWS 48 guy. He asked several questions that all point to some confusion about .22 caliber being more efficient than .177 in a given gun. I know I have mentioned this casually in more than one posting, but today I’d like to address it head-on. Incidentally, this phenomenon does not contradict the fact that light pellets are more efficient in spring guns, while heavy pellets are more efficient in pneumatics and gas guns. They are two separate issues.
What does efficient mean?
A pellet shot from an airgun has energy that relates to its weight and the speed at which it travels. This energy is imparted to the pellet by the airgun mechanism – regardless of what type it might be. Therefore, efficiency must mean the amount of energy the pellet is able to retain relative to the energy budget of the gun that launched it. This question is limited to one specific airgun, and is not a means of comparing one gun to another or one powerplant type to another. Since foot-pounds of muzzle energy is the common expression of the energy of a pellet, we will use it to examine this question.
I’m not going to theorize about this relationship. I’ll just present some facts that illustrate my point quite clearly.
Let’s begin with a spring rifle
Because many airguns are identical except for caliber, testing is easy. All you have to do is rebarrel a gun and measure the maximum energy in both calibers. I did this years ago with a Beeman R1. In .177, the rifle shot 6.9-grain (that’s what they weighed at the time of the test) RWS Hobby pellets at 1,057 f.p.s., for an energy of 17.21 foot-pounds. In .22, the gun shot 12-grain Hobby pellets (once again, the actual weight at the time) at 907 f.p.s., for a muzzle energy of 21.93 foot-pounds. That’s an energy increase of about 21 percent.
Notice that the velocity drops as the caliber increases. I believe that is where many people become confused. They don’t bother to work out the energy levels. They just assume that faster means more powerful, and it doesn’t.
Another spring rifle test
I also happened to test a Beeman Kodiak in .177 and .22 calibers. The .177 was very weak at just 18.9 foot-pounds, while the .22 got 24+. I also tested the same gun in .25, which boosted the energy up to 27 foot-pounds. In fairness, the .177 wasn’t a factory barrel, but one that had been sleeved with a .177 insert, so let’s not accept its energy as fact, but I doubt there would be a tremendous increase with a factory barrel, so the relationship remains.
One more springer
This one was a Whiscombe JW 75 with all four barrels (.177, .20, .22 and .25). The barrels can be changed in a few minutes, which makes this a very quick rifle to test. The best power I got was 21+ foot-pounds in .177, 24+ in .20, .28 in .22 and 31+ in .25. That’s almost linear!
Now for a PCP
The easiest PCP I know of for this test would be any of the AirForce rifles. They are made to change barrels in a few minutes and are even easier to change than the Whiscombe. A Talon SS that I tested in .177 shot a 10.6-grain Beeman Kodiak pellet at 944 f.p.s. for a muzzle energy of 21 foot-pounds. It shot a 21-grain .22 Kodiak at 732 f.p.s for an energy of 24.99 foot-pounds.
Where does it end?
This energy increase does not continue forever. At some point, you reach diminishing returns and the energy starts dropping as the caliber increases. The rifles I have selected to demonstrate the relationship are all very powerful airguns. What if we were to look at other examples? As it turns out, there are two good ones.
The RWS Diana 48/52
The RWS Diana 48/52 was made for a time in .25 caliber. You could buy it in .177, .22 or .25 – your choice. Now, I don’t have any test data and it would be hard to obtain, because this rifle has a pressed-in barrel that’s not easy to exchange. But just from the advertised energy, we get this: .177 cal., 18.54 foot-pounds; .22 cal., 21.59; and .25 cal., 21.79 foot-pounds. The .22 and .25 are virtually the same. There will be more variation from gun to gun than between the two calibers. Apparently, this rifle peaks in .22 caliber.
This is a lightweight breakbarrel that was used several years ago by BSA as an entry-level airgun to break into the American market. It performed as follows: .177 cal., 13.9 foot-pounds; .22 cal., 15.8 foot-pounds; and .25 cal., 14.9 foot-pounds. I would guess that the compression chamber did not compress enough air for the .25-caliber pellets.
I hope these data are convincing, but if not, you can always conduct your own tests to see what you discover. I believe you will see similar results, but if not, I’d like to hear about it.
29 thoughts on “Fact: .22 pellets are more efficient than .177”
B.B., have you ever chronied your 22SG with a 14-ish grain pellet? Im interested to see what the velocity is so I can get an idea of what it can do with heavier pellets, or do you have that info already? That would be great, thanks for any help.
I would have to agree about your general train of thought here. I have a RWS -48 , and I looked hard at the “numbers” prior to choosing the caliber to order it in. Since energy transfer was the goal, and seeing that 22 & 25 cals were even # wise, I chose the 25. Simply has more frontal area, and you have fewer shoot-throughs when hunting. The trade off was the larger pellets don’t shoot quite as flat as the 22 does. My first 22 cal was a Crosman 622 Pell clip repeater, shooting at about 450 fps, and that teaches you how to shoot something with a more rainbow like trajectory.
Don’t go away!
You are the only person I know right now who still owns a .25 caliber RWS sidelever. Please describe how you like it. I am especially interested in velocities with certain pellets (you tell me), accuracy and so on.
Do you find the Diana Magnum domed pellets work well in your gun?
The rainbow trajectory is no hinderance when you know your gun. I also shoot a Trapdoor Springfield in .45/70 and it has the same problem with the 405-grain bullet. But if I do my part, I don’t need to miss.
Please tell all,
I can’t lay hands on any hard data, but if my memory serves me, I got just over 500 f.p.s. with Crosman Premiers. I checked that against James House’s data in his book, “American Air Rifles,” and it seems correct.
These articles are really helpful, but especially on this article on pellet weight, I cannot find the weight for pellets, it is not even printed on the cans. Is there any where that that can be found?
Well, duh! I just looked on your web page and the weights are right there! Unfortunately the ones I use from Wal-mart are not there. I use the Beeman coated hollow point and I am shooting the Marksman 2004 (P3) and now (ain’t Christmas grand?) the S&W 656 with the 4, 6 and 8 inch barrels. It would be nice to see something written on handguns too.
B.B. & other readers……..
I like my 25 cal 48, and continue to experiment with it. To date, Beeman Silver Ace pellets (25gr) have offered up the most consitant groups, averaging 490fps at the muzzle (F-1 Chrony). I have tried the RWS/Diana 21gr pellets, but find the mid weight 24-26gr (while slower), are better shooters. One thing that is different is that I am lubing these with TC Bore Butter. I enjoyed shooting an H&R Huntsman in 45-70 years ago using a Lee 340gr bullet mold…(charged with Black). Shot lots of 45RB out out of Green Mountian barreled T/C as well…..GREAT FUN. But one point that seemed to make a difference was lube, and what type. Am trying that same mindset with this rifle and will work in earnest this Spring to complete my testing with 3 different lubes. I respect that many folks think this is a waste of time, but its just another intruiging question to be answered. AM working with heavier bullets in the 30gr range next, what I have tested so far shows tighter groups the greater the range becomes. Big heavy pellets (like bullets), deviate less, and consistancy is the name of the game in any type of shooting. Thanks to B.B. for your questions, and to all the participants of the BLOG for sharing their knowledge.
I was going to send you to the Beeman website, but they don’t list pellet weights there. I weigh mine on a powder scale, and I’ve written articles about that.
I’ve also written plenty of articles about air pistols. The index for the first seven months of posts is on the Semptember 30 blog. There is also a Google search widget on the blog that only searches this one blog – for the first question.
I just received a Marksman 2004 today, so I will be reviewing it for you soon.
Thanks for your comment. I enjoy reading about your .25 RWS, and I know others do, too. We’ll be here when you want to tell us more.
BB: Beeman does list the weights for their pellets (among other stats) here. 😉
Finally got my Gamo CFX today (it was delayed by the nasty weather we had up here in NY tuesday), I’ve been playing with it all day.
This being my first “adult” airgun (I’ve had a few cheaper crossman multi-pumps as a kid), I don’t have much to compare it to. However, as a long time rifle/pistol/shotgun shooter/hunter, I know my way around firearms quite well.
The CFX is heavy! With the BSA 2-7×32, it’s around 8.5 pounds That’s not really so bad, as I’m used to lugging around a benelli nova crammed full of 3″ magnums. But compared to my ruger 10/22, or marlin 17hmr, it’s kinda chunky. It’s also pretty long. But I actually like the size and heft of the gun. It adds a measure of stability and recoil absorption. Though on long strolls, it could be tiresom without a sling. I’ll reserve judgement on that point for now.
It’s very accurate. Before I mounted the scope, I put about 25 rounds through it using the open sights (which are quite nice, with one caveat I’ll discuss below) to get a feel for the gun and “burn” off excess factory lube (after wiping it down, and running a felt patch through the bore, of course). The trigger is fine, if a bit “creepy”, which from all I’ve read (alot), seems a common complaint on new Gamos. I quickly learned where the trigger breaks, so it’s a non-issue for me.
I must admit, I initially ignored advice on proper springer hold that’s yelled from the top of every mountain of airguns. That was a mistake! Use that “safecracker’s” hold! I was grouping over 1.5″ before I grumbled and caved in. 😉
After mounting the scope and doing some basic adjustments to get pellets on the paper, close to center, I settled in with a couple of sandbags to test grouping at 20 yards with 4 types of pellets (gotta love pyramid air’s pellet deal). Gamo Pro Magnums, Gamo Pointed Magnums, RWS Superdomes and Beeman Trophys (I really wanted to try the JSB exacts and crossman premiers, but they were out of stock when I ordered my rifle). Both Gamo pellets grouped almost identically, a bit under 1″ (.81″ for the Pro’s, .82″ for the points). Not great. While the beemans were great, grouping a bit over a half inch (.69″ c-t-c, according to my calipers), the rws superdomes were TIGHT! .47 c-t-c. Not bad for a brand new gun. I know that I’ll tighten those groups even more as I gain familiarity with the CFX, and it “breaks in”.
All my groups are the average of three five shot groups with short breaks between each group. I conducted my tests/sighting in my 30 yard pistol/rimfire/bow range which is technically outside, but shielded from the elements by sturdy plywood walls and roof, so wind wasn’t a factor. As I write this, I’m smacking forehead at the realization that I could have scanned my targets and posted links, but alas, they’re out with the rest of the trash. :/
Cocking effort is easy. The specs say 35.5 pounds, and that feels about right. No crunchy/springy sounds. Firing noise is surprisingly quiet, without an obvious springy twang, but with a strong, short buzz. It’s far quieter than any multi-pump I’ve ever fired.
Beware the front sight! It’s plastic dovetailed into plastic and can get knocked loose, at least on my gun. :/
The “cheap” feeling part of the gun is the barrel shroud/muzzlebreak part. It’s not really cheap, but it feels a bit thin, something of an afterthought who’s primary purpose is for the cocking lever to snap into. Though the mounting point under the break could be useful.
The scope rail is good, raised about 1/8th” above the cylinder, with 4 holes for stops, and another smaller hole at the very back end, who’s purpous is unknown to me.
The synthetic stock is VERY nice, solid, with a good texture. The blueing of the barrel is beautiful, similar for the cylinder and cocking rod, though not as smooth on the latter two, but still fine.
Overall, I really like the CFX. I’m going to have a great deal of fun with it (I already am!).
My next order from pyramid will definitely contain jsb exacts and crossman premiers. If they shoot better than the rws superdomes, I’ll faint with joy (then promptly let you know!). 😉
Thanks for all the advice you provide, BB!
Now, THAT, ladies and gentlemen, is how to post a comment!
Thank you for your DETAILED report of the first encounter with the CF-X. I can tell you’re going to do okay with your new rifle.
You are the second guy to mention the weight of the CF-X. I was raised on adult spring guns, so anything under nine pounds is a lightweight! And then I go back to my firearms and grumble when they weigh over seven. I guess that’s how the world turns.
I hope the others will report with as much detail as you have,
I have a Diana/RWS 48 in .20 cal. and have had some fun using it. Then a friend’s child tried to close the sidelever without releasing it first. Ouch! I am waiting for the replacement part…but a friend of mine also recently purchased a .20 cal. Diana/RWS 48 with a monster scope on it. Wow! not lonly can it hit the cap of a water bottle at 25 yards, but I could actually see it well through the scope.
Question? Is there someone out there who has had any experience with the Brocock “BACS” air cartridge pellet gun? I recently viewed one on a web site and I’m interested to learn more about it.Hopefully someone can help me. JR.
If you don’t get any answers I’ll do a Brocock posting next week.
B.B., I did find some information on a review web site and it was helpful. But I’ve been reading your keen insides on air guns for months now and I trust what you have to say. SO please go ahead and post your comments on Brocock BACS air cartridge guns. JR.
bb, have you ever done a report on a Daisy Powerline 953. I think they are great guns for anyone(especially beginner target shooters). I found the set on sale for $40 and I immediately bought it. My uncle has about 20 guns and he loves it. It is easy enought o use where my 8 year old sister can use it. I usually get great groupings(without a scope from about 10 yards) and it shoots real nice. I also like where you can change it from single-shot to a five shot clip. I also like the way it self loads the pellets from the five shot clip. All other pump, multi shot air guns I’ve had I would have to push over the clip. It is a great gun and I think (isn’t it $80 on Pyramid’s sight) $80 dollars is a good price.
To find whether I’ve covered a gun, type it in as a search term on the current page of the blog. The search is located on the right side of the page. I have done the 953.
I don’t know why but I want to get an RWS 48 in .20 caliber too lol. Getting a 52 or a 54 would be a waste since the money is sunk into a nicer stock and for a right handed person to boot (i’m a lefty). Robert Beeman always has good things to say about the .20 caliber pellet so I figured it couldn’t hurt to try it out. I figure this air rifle would be a nice step up from the Mendoza RM-200 I just recently purchased. It’s a nice enough rifle in it’s own way but air rifles are addictive and fun.
Looks like not much posted here recently, but I just wanted to add that I have documented the same increase in power going for .177 in an R-1 to .22 cal. This was thanks to Tom Gaylord’s book on the R-1. I bought an R-1 in the late 1980’s based on my research from the 1970’s. (maybe not such a good idea) At that time no one seemed to praise the .22 caliber. So after years of waiting to justify the price of the R-1, I picked up the .177 version and shortly after ordered Tom’s new book which quickly explained why the .22 was better. (to be fair Tom Hotzel’s book came to the same conclusion) Another ten years passed before I ordered a .22 caliber barrel. This gave me the chance to test the exact same power plant with the two different barrels and the .22 had much great energy. The only thing I disagree with is BSA’s lack of energy in .25 caliber. I have a Lightning XL in .25 which gets 18 ft lbs vs. the 16 ft lbs they list for .22 cal. Maybe because it is a newer version? I enjoy the BSA gun a good bit over the Patriot that it replaced. It is 6.8 lbs without a scope and easy to cock.
It took about 30 years, but in spring guns I have come to the conclusion power is not everything!
I was wrong again. On the BSA Lightning a web site said the actually tested energy was 16 ft lbs in .22 and 18 ft lbs in .25. I finally got around to testing my rifle and the best pellet is putting out 15.7 ft lbs. While I know not to believe manufacture estimates, I was fooled into believing the “our test” numbers. Silly me. So I’m guessing the .22 is as good or better, that ok thought as I have lots of .22’s and the .25 justified adding another to my collection.
I also have a RWS 52 in .25. I get fantastic groups with the 21 gr. Diana Magnum domed pellets. Pellets are no longer available 🙁
Has anyone tried the Rhino 19 gr .25 pellets?
Due to what reason that .22 is more efficient than a .177? Weight? Size?
It is probably because the .22 has a greater area upon which the compressed air can act. So it is more efficient.
If the pressure is equal as in the Benji 392 and 397 the force difference on the pellet should be (0.22/0.177)^2. This gives a 22 about 1.5 times more energy all things being equal. Looking at measured velocities for the 392 and 397 on the interwebs, it looks like realized gain is about 1.2 to 1.4 so about 35% more energy.
I've heard that a .177 spring needs to be stronger than a .22 down to needing more punch to get the pellet through the rifling…. is this true?
I've heard that a .177 spring needs to be stronger than a .22 down to needing more punch to get the pellet through the rifling…. is this true? Person
That's not the case. .177b and .22 spring guns use the same springs. .177 is less efficient, but it doesn't need a different mainspring.
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It’s well known that a heavier projectile will retain more of its energy downrange than a lighter one – muzzle energy and ballistic coefficients being equal and .22 will give you more shots per charge than a .177 for the same rifle. Also airgun pellets normally have skirts which are not designed for supersonic speeds, they slow rapidly and as they pass back through the sub sonic barrier, the reverse shockwave causes them to spiral wildly.
But here’s the rub. If you’re hunting with an air rifle, you are typically going after small game with an instant kill zone (heart/ lungs, brain) of 1″ or less. You have to be able to place the pellet in that zone every time and at varying ranges (to the nearest yard). The easiest way to achieve this is to have the flattest trajectory possible – to forgive errors in ranging. The sweet spot for average airgun pellets, in my experience is around 900fps. This equates (depending on pellet weight) to around 16ft/lb in .177, 24ft/lb in .20 and 30ft/lb in .22.
Incidentally, it requires around 4ft/lb to kill a rabbit with a head shout. My 15ft/lb .177 retains 7ft/b at 60 yards with a 8.44 grain pellet. Dead is not a quantity, nor is it comparative, dead is dead.