DPMS 260 Rem 3rd round flyer any suggestions

[STI_1911_Guy]

Hello,
I just purchased a dpms LR 260 rem. I have been shooting it for a couple weeks now with federal 120 gr BT, remington 140gr cor-lokt and a couple handloads with 123 gr sierra matchkings 45 gr hodgdon 414 and federal 210M. In every one of the groups the first two rounds would almost be touching (some closer than others)then the 3rd round would open the group to about an inch or a little over.I have only been loading 3 in the mag and have not tried single loading or a new mag. Is this common or am i missing something simple. I know i cant put every group in one hole but its too much of a coincidence to be the 3rd round every time and open about the same amount every time. I also replaced the factory handguard with a dpms quad rail and the barrel was torqued to 49 FT-LBS. any thoughts or suggestions would be appreciated. Thanks.

 

[T-Hoe]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Have you tried any other loads?

 

[SScott]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Single load each round to prove the feeding system, then you can look at things past that.
I polished the feed ramps on my DPMS .308 and it seemed to help gain a little accuracy.
Good luck, SScott

 

[STI_1911_Guy]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Those are the only loads i have tried but i have some corbon coming with 142 gr sierra matchkings. I was going to try a group like normal to make sure it is doing the same thing then load single then keep the brass and try some more handloads. I will also try polishing the feed ramp. Thanks for the advice.

 

[puncher]

Re: DPMS 260 Rem 3rd round flyer any suggestions

I would load more in the mag. then see if the flyer is the one comeing off the follower.

 

[Bozcoyote]

Re: DPMS 260 Rem 3rd round flyer any suggestions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: puncher</div><div class="ubbcode-body">I would load more in the mag. then see if the flyer is the one comeing off the follower. </div></div>

yea what he said . have the same thing with my Oly .243 WSSM with my home made mags. But mine likes to misfire on the last rd also.

 

[jacq220]

Re: DPMS 260 Rem 3rd round flyer any suggestions

try removing your bolt stop and see if the problem continues.

 

[STI_1911_Guy]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Alright i will start trying some of these suggestions and see what happens. Thanks for the help.

 

[Bob L Swagger]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Check this out... You are not the only person with a problem like this with a DPMS rifle. FYI my father is having the same flyer issue with his .30 remington ar (made by DPMS) it was sent to them for repair over a month ago. Apparently it is on its way back from DPMS as we speak, I'll let you know what they did to rectify the issue. I e-mailed the person in the below link and he said DPMS tried 3 different barrels until they got one that was consistent.

http://www.ak47.net/forums/topic.html?b=2&f=30&t=198143

 

[Bob L Swagger]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Just beware of the work you could possibly receive from DPMS if you send it in to them.

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2308982#Post2308982

 

[ranger1183]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Put 4 rounds in the magazine but only fire the first three. That way your rifle won't recoil differently on the third shot. A different recoil will often (always?) cause a different bullet trajectory and thus open up the group.

 

[BCP]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Semi AR's will often through the last round in the mag differently. I did some load development with 4 round groups and every single one the 4th shot was roughly one minute lower. Every time.

 

[Casey Simpson]

Re: DPMS 260 Rem 3rd round flyer any suggestions

I've been working with this issue too. I think it has something to do with feeding. A round tip, at random or regularly, strikes the feed ramp or the barrel extension disturbing the seating depth, changing pressure, velocity, point of impact........ So a certain ogive might function better...or not, or bullet weight, design, magazine lip adjustment. Just get a GAP or JP and have fun shooting. I think that's what I'm gonna do next time. By the time you get a mass produced model shooting right you could've bought a custom, ya' gotta wonder.

 

[bowslngr]

Re: DPMS 260 Rem 3rd round flyer any suggestions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: STI_1911_Guy</div><div class="ubbcode-body">Those are the only loads i have tried but i have some corbon coming with 142 gr sierra matchkings. I was going to try a group like normal to make sure it is doing the same thing then load single then keep the brass and try some more handloads. I will also try polishing the feed ramp. Thanks for the advice. </div></div>

You might find that the Corbon loads have too much port pressure for your AR. That was the case with mine. I didn't consider it much of a loss because it wouldn't group the Corbon loads very well either. No problems with any other factory loads I have run through it though.

 

[sobrbiker883]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Last round out of the mag flyer is a recoil issue. The rifle cycles differently. Single load or load more in the mag. Removing the bolt stop can help, but it'll still be cycling differnt sliding home empty tather than stripping a round....

Feeding issues causing bullet displacement or alignment issues will usually show up randomly or on every round out of that side of the magazine.

bowslnger-if the Corbon loads had too much port pressure for your system then the poor grouping isn't reflective of the load's quality.

DPMS is hit or miss on wht you get, but if its grouping and then tossing the last one in the mag try a fuller mag.

 

[Kyshooter]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Agreed with the comments on the change in the recoil impulse due to bolt locking back. Let us know if that changes things.

 

[STI_1911_Guy]

Re: DPMS 260 Rem 3rd round flyer any suggestions

Thanks for the thoughts on the port pressure. I am going to shoot the corbon but am really just looking for the brass. I want some nosler custom but they are out of stock every where i look. And this DPMS seems to group very well with the first 2 so i am hoping the recoil thing takes care of it.We just got hammered with snow in michigan so i am going to hopefully tunnel to my bench and shoot it this weekend. And i will post the results.