Crosman M1 Carbine BB gun: Part 2
by Tom Gaylord, a.k.a. B.B. Pelletier
M1 Carbine on top and Crosman M1 Carbine below. A realistic copy!
Today, we’ll take a look at the velocity of the Crosman M1 Carbine BB gun. My gun is one that has a plastic Croswood stock, which means it was made between 1968 and 1976. It doesn’t have any indications of having been taken apart, so I’m assuming that it’s factory original.
Strange spring-piston gun!
This rifle is unique in that it has a valve. Despite being a spring-piston gun, there’s a pop valve in line with the piston. It remains shut until overcome by pressurized air. A small coiled spring holds it shut as long as possible. That allows the maximum air pressure to build up, so the BB doesn’t start moving before the piston has almost reached the end of its travel.
Most BB guns use a hollow tube to push the BB off its seat and get it up to about 50-80 f.p.s. Then, the compressed air comes through the air tube and blasts the BB on up to terminal velocity. But the Crosman M1 Carbine and the Crosman V-350 action from which is is designed do not have the tube. So, the compressed air is held back until it reaches overwhelming pressure, and it’s the only thing that acts on the BB. How well does it work?
Daisy Premium Grade zinc-plated BBs
The first BB I loaded was the Daisy Premium Grade zinc-plated BB. I’ve found these BBs to be very uniform and larger than some on the market. They measure 0.171″ to 0.173″ in diameter, and their surface is smooth, though not as smooth as some. They weigh 5.1 grains, on average.
Daisy BBs averaged 383 f.p.s. in the Crosman M1 Carbine. The range went from a low of 365 f.p.s. to a high of 391 f.p.s. That’s a pretty large spread for a spring-piston BB gun, but the average velocity is also on the high side. We’ll have to wait to see how accurate they are; but in my experience, Daisy BBs are always near or at the top, as far as accuracy goes.
BBs are loaded in the front of 2 holes in the upper handguard of the gun. The rear hole is for oiling the piston seal, which on this gun has a huge impact.
The BBs load into the 22-shot gravity-fed magazine through a hole in the front of the upper handguard. Pull back on the operating handle to open this hole for loading. Although Crosman says the magazine holds 22 BBs, my gun holds 23.
The rear hole in the upper handguard is for oiling the mechanism. You can also see BBs through the hole if the gun is loaded.
Daisy Premium Grade zinc-plated BB on the left, Umarex Precision steel BB on the right. The Umarex BB is visibly smoother; but in tests with many guns, these 2 BBs are similarly accurate. It’ll be interesting to see how the Crosman M1 Carbine handles each BB in the accuracy test.
Umarex Precision BBs
Next, I tried Umarex precision steel BBs. They averaged slightly less velocity, as 375 f.p.s., but the spread was also tighter. The low was 367 f.p.s. and the high was 382 f.p.s. That’s a range of 15 f.p.s., compared to 26 f.p.s. for the Daisys.
The Crosman M1 Carbine trigger is light, breaking at 2 lbs., 13 ozs. on the test gun. The blade is very thin, though, and that makes the pull feel heavier.
This airgun is performing at the peak of its power right now. An average Crosman M1 Carbine will shoot around 350, so this one is certainly a little hot. I can’t wait to see how well it does in the accuracy test.