6BR on the AR-15

[jpretle]

My search has failed. A while back there was a discussion on this topic. I was wondering if someone on this board has 'hands on' experience w/ this set-up. If so, please advise. I need info.
Yes I've checked out AR Performance and BRAT.

 

[9H_Cracka]

Re: 6BR on the AR-15

In order to make it work you have to turn the rim down on the brass to fit in a 762x39 bolt. This causes feeding issues for many (bolt over riding the rim and wedging on the case). Many have tried to make it work and failed.

Hence the 6mm AR and its variants popularity.

http://www.6mmar.com/

6mm RAT info here:

http://www.accurateandreliablerifle.com/

All this said, I saw someone out there advertising a working 6BR AR in the last year that did not require the rims turned down but cannot recall who. I think they were out of Durango CO.

 

[jasonk]

Re: 6BR on the AR-15

Maybe this one?
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2103945

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2245182

 

[jpretle]

Re: 6BR on the AR-15

Thanks Jason. Those are the ones. I was hoping there was some up to date info, but that is not the case.
What search did you use to find the threads?
Thanks

 

[Chris F]

Re: 6BR on the AR-15

I have an upper in 6BR. It's based on Oly upper parts and built by Holliger. Shoots standard BR cases, no turned rims. The biggest concern should be mags. If you are considering a build, make sure you sort the mags out before you commit to a path. Mine feeds and operates just fine.

There's also another out there. I have the bolt and extension from this one, but haven't had it built yet.

 

[FCS]

Re: 6BR on the AR-15

What magazines are you running with 6BR?

 

[bustin]

Re: 6BR on the AR-15

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jpretle</div><div class="ubbcode-body">Thanks Jason. Those are the ones. I was hoping there was some up to date info, but that is not the case.
What search did you use to find the threads?
Thanks </div></div>
Too busy to build custom barrels but the bolts and extensions are available.
www.AR15Performance.com- Pueblo West bottom of the page

 

[bustin]

Re: 6BR on the AR-15

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: FCS</div><div class="ubbcode-body">What magazines are you running with 6BR? </div></div>
The Oly/Brat system uses mags with the mag catch enlarged on the top side so the mag sits lower in the receiver and with a wssm it is a center feed. The Oly system has a special carrier, bolt extension and requires a receiver that has been enlarged to 1.050 where the barrel extension slides in.

The AR Performance system uses 6.8 mags, PRIs allow a OAL of around 2.3" Uses a standard AR15 carrier and receiver, the bolt and barrel extension are different.

 

[mecher50]

Re: 6BR on the AR-15

In the process of building a 6brx with the ar preformance bolt and extention. Will be using 6.8 spc mags I will let you know how it turns out.

 

[onlyfineknives]

Re: 6BR on the AR-15

I just got back my 6brx from AR performance.

I haven't worked up any loads yet, but I just grabbed some extra bullets I wasn't going to use to fireform and threw together a load of 90gr berger, 30.5gr of varget, and rem 7 1/2 primer jammed .025 to .030 to fireform.

While sighting in the gun, I noticed it was grouping really well, so I decided to put it on paper. With no rear bag, only my hand for rear support, I shot 5 half minute groups in a row with the smallest being .39 and the largets .52 (5 shot).

I'm anxious to work up real loads now.

 

[bustin]

Re: 6BR on the AR-15

Guess the S-Carb treatment didn't hurt the accuracy any.
Let me know what you think about the Melonite reducing copper fouling after you have had a chance to shoot it a while.

 

[onlyfineknives]

Re: 6BR on the AR-15

Harrison,

I only have 105 rounds through it so far of fire form loads, but so far it seems to not be fouling bad at all. I've got another 95 rounds to fireform and then I'll start load development.

I'll keep you up to date with results.

Thanks again for your help!

P.S. The 5 half minute groups I shot fireforming were after shooting 20 rounds before. So it maintained the half minute through 45 rounds easy. After I work up loads, I'll probably let it go around 250 rounds before cleaning to see how it does.