DPMS Repr jamming issues

Midwest_Shooter

Private
Minuteman
Oct 9, 2014
5
0
I just bought a dpms Repr. It's a beautiful gun. When I went to break it in (shoot once, bore clean, repeat 25 times) it jammed or seized up twice in those 25 rds. When I say jammed, it wouldn't fire the round and I couldn't extract the round without fighting it for a while. I also noticed that when I eject a non fired round their is a small strike on the primer. I was using fairly cheap ammo PPU 150g. Are these problems new with breaking in a mid to higher end ar10?
 
When did it start jamming? When you say bore cleaned, do you mean just the barrel. Did you clean your bolt, firing pin....etc. Excessive lube will trap carbon and create this type of jamming...especially when using dirty ammo. Just a thought.
 
Check the chamber for any burrs or left over metal shavings from machining. This may not be allowing the round and the bolt to go into full battery, which would cause your issue with it not firing. It could also could contribute to it jamming up as it can wedge the round in there.

Another thing that can cause this problem is an our of spec bolt. I had a 6.5 Grendel that had an issue very similar to this. Swapped out the bolt and she ran like a champ after that.

As for the little mark in the primer from the firing pin, this is normal. DPMS doesnt have a spring on their firing pin like Armalite does so when you chamber a round, you will get a little dimple from the firing pin.
 
I'd say at about round 10 and 21. It was during the break I'm process. A few rounds did hit the ground before I could catch them. I wiped them off before loading them into the mag. I cleaned the bolt and firing pin before I went out. After every shot I just cleaned the barrel.
 
I did check the gun for shavings and unusual wear. I didn't see any shavings but I took a picture of the bolt carrier and noticed a little wear where it locks. I took a picture. photo.JPG Are the grooves on the bottom normal?
 
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Lube the shit out of it, cycle the bolt a couple dozen times, and then shoot it. Eliminate that as an issue. A lot of new ARs need to be lubed up. Cleaning a rifle also removes lubricant, and DI ARs are best when shot "wet".

I also wouldn't classify DPMS as a "mid to higher end AR". You could legitimately have a problem gun, which wouldn't surprise me with DPMS. However, the LR308 line tends to be better quality than their AR15 line.
 
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I'd say at about round 10 and 21. It was during the break I'm process. A few rounds did hit the ground before I could catch them. I wiped them off before loading them into the mag. I cleaned the bolt and firing pin before I went out. After every shot I just cleaned the barrel.

If you haven't cleaned the bolt again check to see how much fouling has accumulated especially on the firing pin. If it's muddy, pasty it could be the problem. But also consider what CSAR FE said,to inspect for particles. If you find it clean with no apparent particles, try different ammo. If it occurs again you might to let DPMS know as your bolt might be out of spec, again as CSAR FE said.

My experience with DPMS 308 was couldn't get past 100 rounds without a jam, using PMC which isn't the cleanest or dirtiest ammo. Had to wipe off the mud that had accumulated and continued until I switched over to a Nickel Boron Bolt and applied barely any lube and it ran great. Again,that was my experience. Best of luck
 
If you use good lube, fouling shouldn't be a concern for reliability until you get to the extremes. I have an AR with almost 10k rounds through it since it was last cleaned, and it still has no mechanical malfunctions. This isn't just with AR15s. Quality ARs in all calibers should be able to run for thousands of rounds without concern, as long as they're properly lubricated.
 
Its not normal for the chambered round to fail to fire and your description of the extraction difficulty causes me to suspect your ammo. I would try a different brand of ammunition and see if that helps.
 
I wouldn't consider a 2500$ a low end gun either. I've had a POF and wasn't willing to jump up to the 3500$ rang to get a LaRue or something that nice. I do think that people look at "DPMS" and think it must be a low end gun. Sure they make and have made lower end 1000$ guns, but I from my personal experience, their mid tier to top end guns are great. This will be the first issue I've ever had with one hopefully its just an ammo issue. If not they will send me a new rifle.
 
I have an AR 15 DPMS. It has a 20" barrel and is exceptionally accurate, it also failed to extract occasionally. As it was so accurate I did not want to send it back. I noticed that there were tiny marks, almost like pin pricks on the neck of the fired cases. I bought a flex hone and oil and honed it a little at a time, after about 6 cycles it is quite reliable, ie only failing to extract once in the last 500 rds or so. I will keep after it with the flex hone, and then chuck a brass brush in the cordless and really polish the chamber. However, if you don't have the time or inclination to work with your rifle, I suggest you send it back and try another. DPMS is a decent company that stands behind thier products, if they don't please inform the forum, good luck.
 
I wouldn't consider a 2500$ a low end gun either. I've had a POF and wasn't willing to jump up to the 3500$ rang to get a LaRue or something that nice. I do think that people look at "DPMS" and think it must be a low end gun. Sure they make and have made lower end 1000$ guns, but I from my personal experience, their mid tier to top end guns are great. This will be the first issue I've ever had with one hopefully its just an ammo issue. If not they will send me a new rifle.

Whatever "tier" they are in has nothing to do with cost. That said, the most expensive DPMS should not cost more than $2k, or you're getting ripped off. Their manufacturing tolerances, finishing quality and quality control leave a lot to be desired. People often mistake accuracy for quality. DPMS is good at making accurate barrels, but so are several other companies. The difference is that companies who make the more expensive 308 ARs like LMT or KAC have high standards, and also tend to have the military and government contracts to back it up.

Maybe it's an issue with ammunition, or maybe it's just simply a lubrication problem. Trouble shoot it and figure it out. If you can't, send it back.
 
Heres another idea I had not seen mentioned yet. You said you had trouble extracting. I had a similar problem once because I was shooting reman ammo from a well known company. Ammo that I shot alot with and had no issues. My friend thought the cases could be bad so he measured the OD of the cases with calipers and then later with a concentricity gage before and after and compared them with match ammo cases and found that the reman cases had never been resized or maybe the cases were resized incorrectly because the resizing dies had been worn down. We tried other surplus and match ammo and they all shot fine. It was just a bad lot of ammo and the store took it back immediately and gave us some different ammo.
 
Regarding the small strike on the primer. As others stated this is normal and I also get that on my AR10. I release the BCG. The BCG slams forward on a unfired round. Then instead of shooting that round, I pull out that unfired round and I have a light tap on the primer. It has never fired a Accidental Discharge. That round is still good so throw it back in the mag and shoot it.

Regarding new AR10s. As others stated, they are just built tight so lube the hell out of everything in the BCG by taking it all apart and lubing all the sliding surfaces. Watch some youtube video if you need to if you dont know how to take apart the BCG. It needs to be wet. As time goes on all the tight clearances will wear down a little and you will notice you wont have to lube it as much. If it still doesnt work wet with other ammo then come back and let us know.