Mosin Nagant 1891 CO2 BB Rifle: Part 2
by Tom Gaylord
Writing as B.B. Pelletier
The Gletcher Mosin Nagant 1891 CO2 BB rifle (gun) is extremely realistic.
This report covers:
• Piercing the first cartridge
• Daisy BBs
• Hornady Black Diamond BBs
• Umarex Precision Steel BBs
• It’s over — for now
There was a lot of discussion about the Mosin Nagant 1891 CO2 BB Rifle last time. Some of you were angry that such an airgun even existed, while others complained about the firearm from which it was copied! That’s like panning the World War II Liberator pistol because it isn’t a sporting arm!
Other folks were intrigued by this gun, but I still heard a lot of warnings. One was that Gletcher CO2 guns all leak — or at least that was one person’s experience. As it turns out, that ties into today’s report, so let’s start there.
Piercing the first cartridge
I was warned by a blog reader that the gun might leak. So when I pierced the first CO2 cartridge, I was extra cautious. And it did leak! For more than a minute, gas leaked out very slowly. I’d used Crosman Pellgunoil on the tip of the cartridge, as I always do, so that wasn’t the problem.
Remember the report I recently wrote about how to make CO2 guns better? That report talked about face seals that are too thick (making the piercing pin too short) that can cause problems with new guns. That was the problem with this gun. So, I cranked the piercing screw tighter, forcing the cartridge into the face seal harder. That slowed the leak but didn’t stop it.
Then, I backed off on the piercing screw, allowing the cartridge to move back because it’s being pushed by the thick face seal. That lets the Pellgunoil get around to the back of the face seal and fix any small irregularities in the metal against which the seal is pressing. I had to do this several times — tightening and loosening — but never to the point the CO2 was escaping around the seal as it does when you remove the cartridge.
Eventually, the leak stopped completely. The gun was now sealed as it should be. Many modern gas guns seal rapidly with a pop when their cartridges are installed, so the procedure I just described may seem strange to many of you. This was what we used to do with most gas guns in the 1960s. I lived through that time, so this procedure doesn’t seem that strange. It’s just that I haven’t had to do it in many years.
I began the test shooting 10 Daisy Premium Grade BBs. The first shot went 414 f.p.s., which I thought was brisk, the following shots all decreased in velocity until, on shot 5, I had a double-feed. That shot recorded 270 f.p.s., but with both BBs going through the chronograph that’s to be expected. The shot after that one (shot 7?) went 394 f.p.s., and then they dwindled again. Shot 10 went out at 391 f.p.s. During this entire string, I was waiting a minimum of 10 seconds between shots.
Hornady Black Diamond BBs
There were some feeding problems with the Hornady Black Diamond BBs. They seemed a trifle large for the magazine, and one actually stuck in the hole where they’re loaded but also come out when shot.
The first shot was a double-feed that registered 311 f.p.s. on the chronograph. After that, the velocities were all over the place. Let me show you:
I will not bother giving the average for this string, because that number would not apply to any actually shot. This is a bimodal distribution, which is fancy talk for saying that there are 2 things happening. In this case, something is happening randomly that puts the velocity into either the high or low category. Bottom line: This is not good.
Umarex Precision Steel BBs
Next to be tested were Umarex Precision Steel BBs. They loaded just like the Daisy BBs, and that gave me hope that they would also do well. They were also the only BB that shot all 10 shots from the gun without a double-feed. But look at the string:
The average for this string was 334 f.p.s., but you’ll notice that none went at that speed, or even very close. That’s that bimodal thing again. Even these BBs, which seemed okay during loading, did poorly in the velocity test.
So, I went back to Daisy BBs once more. This time they started out at 371 f.p.s. and dropped to 297 f.p.s. on shots 9 and 10, which was a double-feed.
It’s over — for now
Okay, I thought. I’ll give it one more chance. I loaded another 10 Daisy BBs. When the first shot was a double-feed at 215 f.p.s., the test was over.
I don’t give up on an airgun often, but I am giving up on this one. However, because it has so many good reviews, I’ve ordered a replacement from Pyramyd Air .
I’m sad bout how this has turned out, because this Mosin Nagant airgun has a lot going for it. The weight of the gun and the rugged construction do put me in mind of a Mosin Nagant firearm. Say what you will about 98 Mausers and 1903 Springfields (and I have said as much as anyone about both of them), the 1891 Mosin Nagant is a classic military rifle that’s earned its rich reputation for reliability and simplicity.
It was a pleasure to handle this Mosin BB gun and cock the bolt that didn’t fight with me because of an overly powerful mainspring. I didn’t mention it, yet, but the rear sight on my test gun is so loose and wobbly that I was wondering if I could put all my shots into the BB trap at 5 meters. Then, when BBs started coming out 2 at a time and bouncing off the walls of my office, I knew I couldn’t.
Hopefully, a new gun will resolve all of this.