Mosin Nagant 1891 CO2 BB Rifle: Part 3
by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- Piercing the first cartridge
- Daisy BBs
- Hornady BBs
- Umarex BBs
- Shot count
- Some observations about the test gun
The first Mosin Nagant 1891 CO2 BB Rifle I tested didn’t work out very well. I noted a gas leak when the first CO2 cartridge was pierced, and that started a list of problems that plagued the gun right up to the velocity test, where it failed altogether. So, I ordered a second gun from Pyramyd Air and that’s the one I’m testing today.
All the general remarks made in Part 1 still hold for this second gun. It’s just as heavy and rugged-looking as any Mosin Nagant firearm. But when I pierced the first CO2 cartridge I noticed a difference.
Piercing the first cartridge
There was no gas leakage when I pierced the first CO2 cartridge in this gun. I never heard so much as a hiss. And the gun started shooting right away.
The first 4 shots with Daisy Premium Grade BBs all registered in the 340-350 range. That was approximately the velocity at which the other gun had shot, so I thought nothing of it. But shot 5 came out at 440 f.p.s. After that, the gun shot in the 400s with everything! It was like it needed to be awakened after a long sleep. Once awake, it came to play!
I disregarded the first 4 shots and started the string with shot 5. The next 10 shots with Daisy BBs averaged 430 f.p.s. I was pausing at least 10 second per shot, if not a little more. The low on this string was 421 f.p.s. and the high was 440 f.p.s. A 19 f.p.s. spread from low to high. At the average velocity, this BB generated 2.09 foot-pounds of muzzle energy.
Next up were Hornady Black Diamond BBs. They averaged 437 f.p.s.; but during this string, I paused for about 2 minutes to take care of other work, and the velocity rebounded partially. The low was 426 f.p.s and the high was 444 f.p.s., and the spread was 18 f.p.s. Th muzzle energy was 2.16 foot-pounds.
The final BB I tested was the Umarex Precision Steel BB. They averaged 432 f.p.s. for 10 shots, and this time there was no unusual pause in the shooting. The low was 420 f.p.s. and the high was 446 f.p.s., so the total spread was 26 f.p.s. At the average velocity, this BB produced 2.11 foot-pounds of energy at the muzzle.
How many shots can you expect from one CO2 cartridge? Given the rather high velocity, I estimated a lower number than I got. I figured the power might drop off after 50 shots, but shot 55 was a Daisy BB going 430 f.p.s. Shot 65 was another Daisy that went out at 394 f.p.s. That signaled the start of a long decline in velocity. Shot 75 was traveling 354 f.p.s., and shot 85 went out at 301 f.p.s. By that time, I could hear the power bleeding off. Since I didn’t want to stick a BB in the bore, I stopped shooting. Eighty-five shots from a single CO2 cartridge is a lot to get from a 400+ foot-per-second airgun.
The trigger is single-stage, and you can feel the pull as the pressure increases. It isn’t exactly creepy, as in starting and stopping, but the blade does move as the pressure increases. It breaks between 3 lbs., 4 oz. and 3 lbs., 12 oz.
Some observations about the test gun
I said in the beginning that this Mosin is exactly like the first one — other than the leak. Well, that’s not entirely true. I noticed that this gun’s removable clip that houses both the BB magazine and the CO2 cartridge does not like to be installed if the bolt is closed. It really helps to open the bolt before installing the removable clip. The hollow nose of the bolt goes around the top of the clip that contains the valve when it’s forward, and on this gun the fit of the bolt over the valve is very tight.
I note, also, that the bolt on this gun is tighter and needs more effort to cock than the bolt on the previous gun. That’s probably the fit of the bolt over the valve. It’s still much easier to work than the bolt on a Mosin Nagant firearm.
We’ve successfully gotten through the velocity testing, and accuracy comes next. I hope this gun is accurate because I really like it.