DPMS problem?

[Alan_H]

anybody have any problems with a new DPMS chambered in 5.56 short stroking? friend of mine bought new has olny shot factory ammo through it and some times it wont fully eject or lock open on an empty mag. pulled gasblock and tube but found no obstructions. im confused????

 

[VTgunner]

Re: DPMS problem?

It seems to me that DPMS is really a luck of the draw. My friend bought a DPMS and it works just fine. Although we both use our agency AR's more than our personal ones. But I also know someone who basically threw his away and bought a Bushmaster because his other was crap.

I'm not an armorer, but there might be a leak in the gas tube preventing the proper amount of gases reaching the bolt. Have a local gunsmith look at it and see what he/she can find.

 

[dtask]

Re: DPMS problem?

Could be that the gas block wasn't properly aligned by the factory.
Could be that the buffer spring needs changing.
Could be that the ammo is the culprit.

Bushmaster & DPMS (and Remington, Cobb, Marlin, AAC, etc...) are all owned by Cerberus. Now, what that means as far as manufacture is concerned(?) I don't know. I know that the R15 from Remington is the Bushmaster Predator without the phosphate coating & with a regular crap trigger.

I had some PMC ammo that was causing the same issue - shoot several types of ammo and then move to a different probable cause.

 

[Alan_H]

Re: DPMS problem?

well my friend and i decided to try my bcg in his rife and his in mine. well then his rifle worked great and mine would short stroke. my rifle is a yhm chambered in 5.56 20"
so he called dpms and whom ever he talked to told him that he was shooting the wrong ammo because most dmps rifles are chambered for 5.56, so when he got home he checked and the barrel is stamped .223??? so what are we missing here?

 

[nicholst55]

Re: DPMS problem?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: alan_h</div><div class="ubbcode-body">well my friend and i decided to try my bcg in his rife and his in mine. well then his rifle worked great and mine would short stroke. my rifle is a yhm chambered in 5.56 20"
so he called dpms and whom ever he talked to told him that he was shooting the wrong ammo because most dmps rifles are chambered for 5.56, so when he got home he checked and the barrel is stamped .223??? so what are we missing here? </div></div>

Sounds like BS to me; I would expect that the bolt carrier key on his BCG is not properly installed (loose). Bushmaster used to be famous, er... <span style="font-style: italic">infamous</span> for this very thing; maybe they transferred some workers to DPMS?

You can either jack around with DPMS trying to get it fixed, or take it to someone who is set up to <span style="font-style: italic"><span style="font-weight: bold">properly</span></span> stake a new bolt carrier key in place. It will probably void the warranty to have someone other than DPMS do the work, but then you must ask yourself just how valuable it truly is to begin with.

 

[bribri]

Re: DPMS problem?

Mine works flawlessly, I would take it back if possible.

 

[Alan_H]

Re: DPMS problem?

well after another phone call DPMS finally decided that some thing was wrong[possible headspace problem] and the rifle will be shipped tomorrow. hopefull a quick turnaround

 

[1stIDvet]

Re: DPMS problem?

I have not had a problem with my DPMS, but I must say DPMS could use a better costumer service. Once waited 20 minutes on hold looking for barrels.

 

[oneshot onekill]

Re: DPMS problem?

I believe 5.56 and .223 have dimensionally slightly different cases. IIRC 5.56 can be slightly longer and this can cause over-pressure and extraction issues on some .223 barrels with "tight" chamber tolerances. Not usually a problem on an AR as most are 5.56 and .223 works just fine in them as well. I'm not really sure how accurate this info is but I read it somewhere recently.

Also, I would have tried a heavier buffer before sending my rifle back. You'd be amazed at what changing buffer weight will cure! I know... it may not make sense since a heavier buffer is harder to get started, but once it's set in motion it also blows back further into the buffer tube because of the weight.

 

[carbinero]

Re: DPMS problem?

I would buy a BCM and sell your DPMS upper. You can mess around with fixing and factory this-and-that and still have a DPMS. BCMs are currently available for reasonable price, so I see little reason to continue with problematic brands.