M14 Forum banner

1 - 20 of 40 Posts

·
Registered
Joined
·
1,491 Posts
Discussion Starter #1
Anyone ever have to send a DPMS upper back to them for warranty work or evaluation? I am having severe accuracy issues with mine (5 inch groups scoped at 100 yards). I used a known good scope, and tried several manufacturers cartridges including PMC 55gr, Fiocchi 62gr, Hornady V-Max 55gr, ADCOM M855 55gr, Lake City M193, green tip (not sure of the military designation), and Winchester 55gr fmj. The upper is attached to a Rock River lower and fits together very well. I have about 350 rounds through it so far. I am just completely frustrated with this setup and don't know where to go from here. A 2-3 MOA group would be satisfactory being that it is the M4 pattern rifle. Any ideas?
 

·
Registered
Joined
·
2,591 Posts
Sir, I would remove the scope to eliminate it as the source of the problem and shoot that upper with iron sights if you can, if not try another scope.

Flat top upper? What type of mount? Can you post pics of your setup?

That rifle should shoot much better than that.
 

·
Registered
Joined
·
1,491 Posts
Discussion Starter #3 (Edited)
It is a flat top upper and I am using XTR extra high rings. The rings are torqued to the upper at 65 inch lbs and the caps are at 20 inch lbs. I have shot it with iron sights also and the results are basically the same.

Here is a picture to the rifle:


DPMS complete upper on a Rock River complete lower

Here is a picture of the target with a 20 round string shooting slow fire:
 

·
Registered
Joined
·
179 Posts
No, never had to send one back. Got 4 of them, all are sub-2MOA with factory loads and sub-MOA with hand loads. Must of got lucky 4 times! :)...O.L.
 

·
Registered
Joined
·
1,848 Posts
...I am having severe accuracy issues with mine (5 inch groups scoped at 100 yards)...A 2-3 MOA group would be satisfactory being that it is the M4 pattern rifle. Any ideas?
I'm sure you already know this but if you're shooting from the bipod and your barrel isn't floating, subtle changes in pressure as you press the rifle down to stabilize it will be transferred directly to the barrel and that would be true whether you're using the scope or iron sights. A clue is that your sample target shows a horizontal grouping within your expectations; it's the vertical dispersion that's a problem.

You might also check DPMS's own forums to see if others are experiencing similar problems with similar rifles and how they handled it (that worked for me).
 

·
Registered
Joined
·
1,491 Posts
Discussion Starter #6
Would that also be true using a sling? Maybe I am pressing down on the bipod. I figured it was just resting on the bipod.
 

·
Registered
Joined
·
1,848 Posts
Would that also be true using a sling? Maybe I am pressing down on the bipod. I figured it was just resting on the bipod.
Slinging up tight can also cause that but would likely add some horizontal displacement, too. I ran into that issue with a bipod and the solution was to float the barrel. Normally, that involves a degree of disassembly I wasn't about to try (and forget about any warranty). My solution was this because it replaced the standard handguard but only attached to the rifle at the rear, thus floating the barrel.
 

·
Registered
Joined
·
1,491 Posts
Discussion Starter #8
$270 for a free float rail? Ouch! Not willing to spend that much. That is halfway to a 7.62mm cast reciever.
 

·
Registered
Joined
·
1,848 Posts
$270 for a free float rail? Ouch! Not willing to spend that much. That is halfway to a 7.62mm cast reciever.
I agree it's not cheap, but it's the only one I know of that doesn't require removal of the sight and gas block but still works. Perhaps shooting from a bag would ease the pressure on the barrel enough to at least eliminate any barrel flex from the equation. I've been following the DPMS 7.62 forum and people have been complaining about many things, including barrels so it could just be their upper.
 

·
Registered
Joined
·
1,491 Posts
Discussion Starter #12
I did tell them that it is on a Rock River lower. I wouldn't think that would effect accuracy. But I don't know very much about the AR platform.
 

·
Registered
Joined
·
1,848 Posts
I did tell them that it is on a Rock River lower. I wouldn't think that would effect accuracy. But I don't know very much about the AR platform.
I don't think it would affect accuracy either, especially with the tight fit you have, but it might affect their willingness to do any extensive parts replacement, especially if they pop it on one of their own lowers, put it in a test stand, and it seems to behave reasonably well.

For instance, you know how touchy they can be about shooting handloads, even if that couldn't cause the problem at hand. Same thing.
 

·
Registered
Joined
·
2,591 Posts
My experience getting service from anybody by e-mail is pretty dismal; if you really want them to respond, call them.
+100, get 'em on the horn.GI6
 

·
Registered
Joined
·
1,491 Posts
Discussion Starter #17
I got an email from DPMS today instructing me to send it in for evaluation. They think it may be the barrel. I'll keep you posted.
 

·
Registered
Joined
·
2,052 Posts
Sir, I would remove the scope to eliminate it as the source of the problem and shoot that upper with iron sights if you can, if not try another scope.

Flat top upper? What type of mount? Can you post pics of your setup?

That rifle should shoot much better than that.
Very good advice. My DPMS carbine will shoot 10 shot sub 3" groups at 100 yards with surplus 55g ball ammunition and Federal M193 using iron sights. Your rifle should do as well or better. The first thing I would check is good cheek weld while using a scope on your rifle. I shot my Colt HBAR better using iron sights than using a scope mounted on it. Turns out I had inconsistent stock weld.
 

·
Registered
Joined
·
300 Posts
do let us know how they take care of you , they have some very good folks in the shop and a pretty good guy in the troubleshooting department
 

·
Registered
Joined
·
1,491 Posts
Discussion Starter #20
I got called yesterday by DPMS' customer service. He said they have my rifle waiting to test fire and give it a diagnosis. They couldn't do it cause it was 35 below and windy. I don't blame them for waiting for warmer weather. They are keeping me in the loop through the process and I appreciate that.
 
1 - 20 of 40 Posts
Top