Building the $100 precharged pneumatic air rifle: Part 4
by Tom Gaylord, a.k.a. B.B. Pelletier
The $100 PCP is built on a Crosman 2100B chassis.
This test was very interesting! It began last week at my outdoor rifle range. Blog reader GunFun1 asked me to try shooting steel BBs in this gun because it was originally built to handle them (when it was in its Crosman 2100B form). I didn’t want to do it because this rifle launches the first couple shots at over 900 f.p.s., and steel BBs rebound like crazy (You’ll shoot your eye out), but I did relent. Last week, I took this rifle to my outdoor range and stuck a 12-inch Shoot-N-C target on the plywood target backer. I then paced off 10 meters and fired 10 BBs at this target.
I thought the BBs would probably miss the target altogether. I said as much to GunFun1 in my comments a few weeks ago. But they didn’t!
I was wrong about this. Shooting offhand with open sights, I put 10 Daisy Premium Grade steel BBs into 1.56 inches. It was actually 11 BBs. I must have miscounted during shooting. I was astounded! This isn’t just good — it’s great! You don’t shoot BB guns at 10 meters when you’re shooting groups!
Incidentally, all 10 BBs apparently went through the plywood target backer. Of course, there are other bullet holes there, so the wood isn’t always present or at its thickest; still, it shows those BBs are moving!
That got me wondering just how accurate this rifle could be. I decided to shoot from 25 yards with open sights, only. I’ll come back and shoot with an optical sight of some kind, but this test is just open sights.
I filled the gun to 2,000 psi for every 10 shots, including for the BBs shown above. After 10 shots, the gun’s pressure has dropped to 1,000 psi.
Crosman Premier lite
The first group of 10 shots was shot with Crosman Premier lites. Based on the 10-meter results for the last test, and also from where the BBs went, I adjusted the rear sight to the right just a little. After the first shot, I looked through the spotting scope to affirm it hit the target. It did, was high above the bullseye and fairly well-centered left and right. So, I left the sights where they were and fired a second shot. When I looked through the spotting scope, I saw it had gone through the same hole as the first! Wow! That was starting out well!
The first 4 shots all went into the same hole. Then shot 5 went higher for some reason.
After taking the picture of the first 5 shots, I shot the remaining 5 shots. That was informative because all the shots spread out to the left. Having the first 5 shots on record allowed me to see that the second 5 were the ones that actually spread out. The 10-shot group measures 1.358 inches between centers.
Next up were RWS Hobby pellets. They did quite well at 10 meters, but 25 yards is about the maximum distance at which wadcutter pellets hold their accuracy.
I adjusted the rear sight down one notch before shooting this group. Once more, I photographed the target after 5 shots.
Air Arms Falcons
The last pellet I tested was the Air Arms Falcon pellet. This time, the first 5 pellets didn’t seem to do that well. And when we see the final 10-shot group, it isn’t that much larger.
Conclusions so far
This experiment is turning out much better than I had hoped. Not only have we demonstrated that it’s possible to make a precharged pneumatic rifle that can retail for under $100, we’re now showing that it can really perform! Of course, the production gun will get many more shots on a fill than the 10 I’m getting, but I do think the maximum fill pressure should be held to 2,000 psi. That will make it easier to build an affordable hand pump, which Dennis Quackenbush is thinking about right now.
The discharge noise of this rifle is quite loud. I was going to recommend not putting a shroud on the gun, but I’m going to change my mind on that point. The customers for this gun will be suburban shooters who need a quieter air rifle, so some sound dampening is necessary.
The trigger on the rifle is heavy, and I would leave it the way it is. I would also leave the bolt-action exactly the way it is on the 2100B. The same goes for the sights. These are refinements people can pay for on higher-priced PCPs. We want to hold the cost of this gun to less than $100 retail.
I do plan on returning to test this rifle at least one more time with an optical sight. That will show the maximum accuracy potential, although I believe we’ve already seen a good indication of it in this test.
The $100 PCP will never replace the higher-priced PCPs that are already selling. It isn’t supposed to. It’s supposed to provide that entry-level step for those who are curious about precharged airguns and don’t want to spend a fortune to find out. I think it’s a very feasible goal and, quite possibly, a profitable one, as well.