Crosman DPMS SBR full-auto BB gun: Part 2
by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- Never run out of bullets
- The feel of the gun when firing
- Here we go!
- Left cartridge first
- Copperheads first
- How does it feel, single-shot?
- Air Venturi Steel BBs
- Hornady Black Diamond
- How many shots?
- Using the BB speedloader
- Full auto
- Test 1
- Test 2
- Test 3
- Test 4
- Test 5
- Test 6
- Test 7
- Shot count
- Feel of full auto
- Trigger pull
- Forgot I had to cock it
Never run out of bullets
The first part of this report didn’t receive that many comments, but those who did say something said similar things. The first was you all want this gun to never run out of BBs. You want it to get no less than 150 shots before it’s time to reload.
When I was a kid I wanted the same thing. I wanted all my guns to hold an infinite numbers of bullet, so they would never run out. Then I went into the Army and got to shoot many fully automatic weapons. I quickly learned that the first thing you want in a machine gun is reliability.
I remember that the M85 .50 caliber machine gun that was designed for fitting inside the turrets of armored vehicles was the worst machine gun to exist since the French Chauchat of WWI. It jammed all the time and seldom would fire an entire belt of ammo without stopping. You had to lubricate the cartridges with fireproof hydraulic oil to keep the gun operating.
“Oh, but with this gun the tank commander can stay buttoned-up while he shoots!” Yeah? Well then why did the M1 Abrams tank, the tank of the 21st century, get the M2 machine gun that was first issued in 1933 for its commanders? Because the more modern M85 didn’t work! Nice to stay buttoned up. Better to have a gun that works.
Bottom line — reliability in a full auto gun is the most important thing. After that comes the number of rounds it holds. So, guess what I’m going to look for today in the DPMS?
The feel of the gun when firing
Reader Halfstep asked me to comment on the feel of the gun when it fires. He remembered my comment about the Umarex MP40, where I noted that even when you fire one round it feels like it’s shooting full auto. I will look at that today.
Here we go!
I really wanted to put CO2 cartridges in this gun and start shooting it when I wrote Part 1 last week, but I held off until now so I can get an accurate shot count. We agreed that this is probably a party gun, so gas consumption will be high when we use it. I just wanted to give you an accurate account.
Left cartridge first
I remembered to install the left CO2 cartridge first. That seals the valve. If you install the right one first it will just leak out. The sealing was quick and I appreciate the Allen wrench that’s inside the magazine for piercing.
To load the BBs I used the speedloader that Tyler talks about on the video I asked you to watch. It is so easy to use! And I have a problem that most owners will never face. Since I want to test the velocity of several different BBs I can’t just pour a bunch of BBs into the loader and then load the mag. I have to go 10 at a time, so let’s see how that works.
This is a Crosman gun, so Crosman Copperhead BBs are first to be tested. Copperheads averaged 414 f.p.s. for 9 shots. I will explain why only 9 in a moment. The spread went from a low of 405 to a high of 433 f.p.s. That’s 27 f.p.s.
After the mag was finished the gun continued to fire tor 4 shots. It’s not supposed to do that. When I loaded the next mag I noticed one Copperhead BB was still in the mag. They are copper-colored so you can tell them from silver BBs. That means the number of shots in that first string was 9, not 10. And that last BB was holding the magazine’s follower from coming all the way up, which must be how the gun knows the mag is empty so it can stop the bolt. I will say more about this in a moment.
How does it feel, single-shot?
I was shooting single shot so I can evaluate the feel upon firing. It does shudder a little like the MP40, but the shudder is not as pronounced, nor does it last as long as the MP40’s. However, the blowback does give you a good feeling of firing.
Air Venturi Steel BBs
Next to be tested were Air Venturi Steel BBs. They averaged 410 f.p.s. with a low of 403 and a high of 416 f.p.s. That’s a range of 13 f.p.s., which was the tightest I saw in all the tests.
Only 9 BBs came out this time, as well, but the gun didn’t fire any blank shots after the string. When I removed the magazine I could see the follower had risen as far as it could. Yet when I loaded the next 10 BBs, there was still one of these left in the mag.
I think the magazine is a little rough on the inside of the BB channel and may need a break-in period. I need to watch it as the test progresses.
Hornady Black Diamond
The final BB I tested was the Hornady Black Diamond that Umarex sells. They averaged 418 f.p.s. with a spread from 411 to 428 f.p.s. That’s a range of 17 f.p.s. All ten BBs fed this time and the gun stopped shooting after the last BB was fired.
How many shots?
To this point I have fired 34 shots. All were fired semiautomatic, which means one at a time. Now it was time to Rock-N-Roll!
Using the BB speedloader
The BB speedloader was easy to use, though the plunger didn’t always want to go down. I found that it helped if I angled the magazine down, so the BBs that had just loaded rolled out of the way. I wouldn’t want to load this magazine any other way than with this speedloader, so I’m happy Crosman provided it with the gun. And, it loaded 10 BBs as easily as it did an unlimited number.
I can’t just pour BBs into the speedloader. I have to know how many are in there because I can’t count the shots in the full-auto mode. I know — poor me. Well, it’s a tough job but somebody has to do it.
Then it hit me — of course I had to count when I shot semiauto, but I thought I had to count all the BBs for full auto too until it dawned on me that the magazine only accepts 25 BB max. Duh! Just fill it and shoot it. It has to be 25. It doesn’t get any easier.
This was a test of the effect of short bursts on velocity. I shot a burst of 6-8 rounds, and followed it with a single shot semiauto. I shot the Black Diamonds because they had no feeding issues. First burst was followed by a shot at 407 f.p.s. A second burst was followed by a shot at 400 f.p.s. Then I shot off the rest of the BBs and reloaded.
Still shooting Black Diamonds. A short burst was followed by a shot at 391 f.p.s. A second short burst was followed by a shot at 386 f.p.s. A third short burst was followed by a shot at 372 f.p.s. I didn’t have to dump the mag because that was the last BB. I reloaded.
Black Diamonds again. Long burst of 15-20? shots, followed by a single shot at 351 f.p.s. Shot off remaining BBs and reloaded.
Long burst, followed by a single shot at 339 f.p.s. Reloaded.
Long burst, followed by a shot at 315. Then fired the rest of the shots.
Then I took an hour break for lunch. That was followed by another full mag of Black Diamonds. The first shot from that mag went out at 376 f.p.s. Followed that with a short burst and a shot at 354 f.p.s. Another short burst and a shot at 335 f.p.s. Another short burst and a shot at 317 f.p.s. Fired the remaining shots. Then I reloaded.
Notice that the long pause caused the velocity to rise considerably. So there is a cooling effect on this gun. But it does not seem to affect the shooting. It never freezes like some CO2 guns have been known to.
Point two is the two CO2 cartridges now have fired 184 shots since they were new and they are still going strong. If you were shooting at a party you would never notice the drop in velocity. And, since the gun is still going I loaded another 25 Black Diamonds.
Point three is since I started shooting full auto there has not been a single malfunction or failure to feed. The gun now stops at the end of the mag, period! I think this magazine has broken in.
I wrote up the previous part of the report, so the gun got to rest for another 10-12 minutes. The first shot after that went out at 313 f.p.s. Okay, she’s now running out of gas. Short burst followed by a shot at 287 f.p.s. A second short burst followed by a shot at 250 f.p.s. Final burst to clear all the BBs out and the gun continued to fire after it was empty. Then the bolt locked up and the gun stopped shooting. I removed both CO2 cartridge (right one first) and they each had a very small amount of gas in them.
In today’s testing I got a total of 209 shots from two CO2 cartridges. I have described every shot for you, so you now have a good idea of what you get from the DPMS.
Feel of full auto
The DPMS has a heavy recoil, so shooting full auto is very pleasurable. The cyclic rate is much faster than the MP40, so it’s a different feel, but it’s still a very realistic feel. This is definitely going to be a crowd-pleaser and a party gun!
The DPMS trigger I’m testing is two-stage and heavy. I measured stage two at 10 lbs. 6 oz. It doesn’t feel that heavy because of the pistol grip, but that’s what it measured.
Forgot I had to cock it
If there was one thing I kept doing wrong throughout the test it was forgetting to cock the gun after it had stopped firing. That is very realistic and not at all like a video game, so bravo for Crosman!
I don’t need to wait to say this. The DPMS is a best buy! If you want full auto that’s affordable, this is the way to go. I’m still going to test the accuracy, of course.