by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • BB’s gun wall
  • .177 caliber
  • Are steel BBs 4.5mm/.177 caliber?
  • Can you hunt with .177 caliber?
  • More good pellets
  • Higher velocity means flatter shooting
  • Twenty caliber
  • Twenty-two caliber
  • Hard-hitting
  • Cost
  • Target shooting
  • Twenty-two caliber
  • Hunting
  • The big .25
  • Expensive pellets
  • Fewer pellets to choose from
  • Big hole!
  • Only one good handgun
  • .30 caliber
  • What does BB recommend?
  • .30 caliber
  • Summary

BB’s gun wall

My late wife, Edith, used to kid me by saying if she went first I would probably jackhammer a pit in the living room and cook my meals over an open fire. I think she was making fun of my domestic inabilities. Well, Edith, that never happened. However, after 4 years of static living I finally decided to make my home my own, so when John McCaslin gave me the replica Girardoni air rifle for my birthday, I decided to hang it on my living room wall. Actually I had already hung a pair of kukri knives there — one a gift from Ton Jones — so the Girardoni wasn’t the first.

Now, BB Pelletier is no craftsman. I rank just behind termites as a worker of wood. So when I say I decided, that is as far as it went. In sharp contrast my neighbor, Denny, is a fantastic woodworker! Denny worked as a patternmaker in the aerospace industry, where he made one-of-a-kind tooling. So he pays attention to the smallest detail.

Denny is always puttering around in his garage/shop, and his wife and family do not keep him gainfully employed all the time, so I “enable” him to do projects for me, from time to time. He did the plaque for the kukries, so when I told him of my idea to hang the Girardoni on the same wall the trap was baited and set. Like the elves and the shoemaker, all I had to do was buy the walnut board and stay out of his way. Then, when the air rifle was up and looking pretty, I brought out my flintlock fowler and showed that to him. Here is the result.

gun wall
My gun wall.

I may not live in a log cabin like reader RidgeRunner, but I have a man cave, too! Next I think I will get rid of the genuine cowhide armchair and replace it with a Cushman Eagle for guest seating! Either that or a tractor seat on a leaf spring.

Enough silliness. Let’s begin today’s report.

As the holiday season draws near (I already have my fruitcake!) many of you are thinking about that next airgun. For some it may also be the first one. So today I want to discuss the various calibers, their strengths and weaknesses and the purposes to which I believe they are best-suited.

.177 caliber

The .177 caliber that is known in many places as 4.5mm is the most popular airgun caliber. It’s also the smallest, which means each pellet takes less lead and that can help to keep cost down, though it is just one of many driving factors.

Are steel BBs 4.5mm/.177 caliber?

Steel BBs are absolutely NOT .177 caliber! They are 0.173 caliber or 4.4mm. But, to keep from confusing buyers, they are labeled as 4.5mm or .177 caliber, and that shifts the confusion over to the 6mm airsoft guns whose plastic balls are also called BBs. You gotta love it!

For the sake of the moms and newcomers I will also lump BBs into the .177 caliber group, and that is the last I will say about them. Because today I am talking about airguns that shoot diabolo (wasp-waisted) pellets. Pellet guns.

One reason .177 caliber is so popular is there are several airgun events that either mandate its use (10-meter target shooting for both rifle and pistol) or strongly encourage it because of a decided advantage (field target). Does that mean that .177 caliber is more accurate than the others? Not at all. It means that through decades of international competition inertia has built up and now it would be too costly for the shooting complexes around the world to switch their expensive transducer-operated and sound-scored target systems to another caliber. Besides, it’s only paper. How much power do you need?

In field target you shoot through a small opening called a kill zone to hit a paddle that triggers the fall of the target. If you happen to hit the side of the kill zone while passing through the energy pushes the target back and may lock the paddle in the upright position, even though a portion of the pellet does hit it. The smaller caliber has less chance, statistically, of hitting the side of the kill zone. I have seen shooters compete with .20 caliber and even .22 caliber rifles. Never saw them win, though.

Can you hunt with .177 caliber?

Yes, you absolutely can hunt with .177 caliber. Like any pellet, the energy delivered is small, so it is essential to hit a vital spot on your quarry, and since .177 is the smallest caliber it is the reverse of field target — it is statistically the least likely to hit something vital when the aim is off.

In the United Kingdom where airgun power is limited by law to under 12 foot-pounds, the .177 gives the advantage of the highest velocity (821 f.p.s. for an 8-grain pellet is 11.98 foot-pounds). In a country where your airgun can be confiscated if it develops over 12 foot-pounds, no matter how close, you want to stay on the “good” side of the limit. Most Americans wouldn’t give it a second thought, unless they were shooting in a field target competition under World Field Target Federation (WFTF) rules.

More good pellets

Another reason to go with .177 is there are more good pellets for this caliber than for all the other calibers combined. Some countries don’t even permit pellet guns in larger calibers!

This caliber is extremely popular worldwide, and because of that the pellet makers have to work hard to keep up with the demand. There are cheap .177 pellets that are no better than sinker larvae, but as time passes there are fewer of those around.

No pellet maker is going to run a target-grade .25-caliber pellet when they can’t meet the demands for .177 pellets. Forget the 400-1,000 people who compete in Extreme Benchrest worldwide. They are nothing compared to the millions of airgunners around the world who only shoot at paper. So, you are the production manager at JSB. What do you do — run 50,000 heavy .25-caliber pellets for the 2020 benchrest season or fill the 2-month backlog for Pyramyd Air — just one customer out of thousands around the world — for the three pallets of .177 pellets (1.5 million pellets) they are willing to pay you for right now? Hmmmm! Tough choice, but what the heck. You like your job, don’t you?

Higher velocity means flatter shooting

Yes a faster-moving pellet does shoot flatter and all other things being the same the .177 caliber pellet will move the fastest, but this advantage isn’t as big as it sounds. Because what it masks is the inability to determine range. A shooter who knows his rifle and can guess ranges can hit more with a 500 f.p.s. .22-caliber springer than someone with a thousand-dollar hyper-velocity PCP who isn’t a good shooter. I’m not saying those who shoot .177-caliber airguns aren’t good shooters; I’m saying the first thing to do is learn to shoot!

The .177 is an excellent choice for plinking, target practice and pest elimination around the home. It’s also good for hunting.

Twenty caliber

The .20 caliber that is known in some places as 5.0mm was popularized by the Sheridan company, starting in 1947. They said at the time they did it because there weren’t any good .22-caliber pellets around, and that was a true statement, but it’s also highly likely they were hoping to “corner” the market with this special caliber. They actually fought an uphill battle because of the decision. American buyers knew .22 caliber and they knew .177 caliber but they were unfamiliar with .20 caliber. Just ask the Remington firearms company how popular the twenty caliber is.

Dr. Robert Beeman liked the .20 though and he convinced many of his manufacturers to make airguns in that caliber for him. He also thought .22 caliber pellets were less accurate, and in fairness they were during the time he was growing up. Because of this there are some very fine airguns in twenty caliber. But not many are being made today.

There are some .20-caliber guns being made, but they are seen by the market as a narrow niche. Remember what I said about the pellet manufacturers and the .177 caliber pellet. Twenty caliber is not the mainstream today and if you choose one you will have to become its champion.

From a power and accuracy standpoint, .20 caliber is just fine. You can hunt with it, shoot targets, and plink. There are no drawbacks to .20 caliber in this respect.

Some call .20 caliber a compromise between .177 and .22, but I think it’s a lot closer to .22 than to .177. You are going to have a hard time finding good pellets for this caliber and you can forget buying them from the discount store. Don’t forget, there was once an 8mm airsoft caliber, but try to find one today!

Twenty-two caliber

The .22 caliber pellet is the second most popular pellet in the world, and at one time in the United States and probably in most of North America, it was the most popular. That means that there are a lot of older airguns in this caliber.

The twenty-two is a fine accurate caliber. The most accurate longer-range air rifle I ever shot (Skan) was a .22. My ASP20 is a .22. Webley once made a couple nearly full-blown target rifles in .22. The Mark III and the Osprey were both made in Supertarget versions. But world-class target rules shut out the .22s, so these guns were just made for informal competition.


The .22 pellet leaves a larger wound channel and impacts with a bigger punch, from a given powerplant, than a .177. The fact that .22 pellets go slower than .177s in the same powerplant is not seen as a disadvantage, because a higher-velocity .177 can go clear through game leaving a nasty but small wound and not shedding all its energy. A slower-moving .22 often stays in the animal, delivering all of its kinetic energy. So if hunting is your game, the .22 is one of the two best calibers to choose.


Twenty-two pellets do cost a lot more than .177s because twice the material is used to make them. Consider that in your decision if you want to shoot a lot and will mostly be plinking. It’s like the difference between .22 long rifle and .22 magnum. Why do you care about how much energy hits the tin can?

Target shooting

This is a toughie to address. If you already own a .22 pellet gun there is nothing that says it isn’t good for targets. But if you are considering buying a new gun, remember the cost and the overkill proposition I just stated.


For hunting and pest elimination .22 is one of the two best calibers, with .25 being the other. HOWEVER, if the pests are small, like mice and wasps, use a .177 if you can. The .22 is way overkill for small targets like that. Also, if the pest is in an area where a miss could put a pellet through the wall or ceiling, keep that in your considerations.

For larger pests like rats and woodchucks, the .22 is the better way to go. Not that .177 won’t do the job; .22 just does it better.

The big .25

Twenty-five caliber pellet guns have been around as long as .177s and .22s, give or take a year or two. In the past they were not popular because the spring-piston powerplants they were in couldn’t shoot them fast enough to make them really work well. But all that changed a couple decades ago with precharged pneumatics (PCP) moving into the caliber. More recently there are spring gun powerplants that are far more efficient than ever. Today you give very little away with a .25.

Expensive pellets

The .25 pellets are very expensive, so I don’t recommend using them for plinking and general shooting. On the other hand, they are one of the two best calibers for hunters. Pay the price for the pellets if you need the extra performance.

Fewer pellets to choose from

There are far fewer .25 caliber pellets to choose from today. The good news is that most of them are premium pellets, but you’re not going to find them at discount stores! If you own a .25 you better be comfortable with buying online.

Big hole!

Everything I said about .22 caliber applies in spades to the .25. They hit very hard and seldom go through game if it is of the appropriate size. You still need to make good shots in vital areas, but if you do the quarter-inch caliber will be your friend.

But the .25 is a specialty caliber. Buy it to hunt with or for larger pests, but unless you are made of money don’t think of it for plinking.

Only one good handgun

I think the TalonP from AirForce Airguns is the only .25 caliber handgun that is worth its salt. If I am overlooking one I apologize beforehand. The TalonP I have shoots 5-shot groups that are smaller than one inch at 50 yards at the 30 foot-pound level. And the gun can be adjusted up to 55 foot-pounds!

.30 caliber

I bet you thought I was done at .25. The thirty caliber is a very recent innovation that is only possible now because of advances in airgun technology. Pellet choices are expensive and very few, and hunting is the primary and almost only purpose for this caliber. If you are looking at a .30 you must have a good reason. Don’t envision it through daydreams on your couch because you may be highly disappointed.

What does BB recommend?

BB recommends either .177 or .22 caliber at this time. I would go with .177 if hunting is a small portion of the shooting you intend doing, and .22 if hunting is half the plan or more. I would always buy .22 over .25 because they are so close in performance and the number of good pellets in .22 is so much greater.


Sometimes the airgun dictates the caliber. Perhaps there is a real beauty and you want it just for how it looks. It’s one single special airgun and it is whatever it is.

Or perhaps you stumble into a purchase of a gun with more than one caliber. Let’s call it a Webley Mark II Service with .177, .22 and .25 barrels. Naturally you buy all three barrels with the gun — you’re not an idiot. You may never even mount the .25-caliber barrel on the gun, but you have it and it adds that much more value to your gun. I own a Whiscombe JW75 that has barrels in all four calibers. I don’t know whether the .20 and .25 barrels have ever been on the airgun. I shoot .177 the most and .22 sometimes.

On the other hand I own a .25 caliber Benjamin Marauder just because several people said the Green Mountain barrels Crosman used to put on them were highly accurate. I never found that to be the case, but I do like the airgun and probably won’t get rid of it. I’ve owned both .177 and .22 Marauders that were as accurate or better than this one, but right now the .25 is all I have.


I hope this little discussion has helped you with your decision of which caliber to choose for that next airgun. I have to make the same decision every time I ask Pyramyd Air for a new pellet gun to test. One big difference between you and me is that I get to send my airguns back when I’m done with them. Only a few tickle my fancy and remain with me.