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a0cake
11-16-11, 21:44
I recently moved to NY so I'm stuck with one pre-ban lower for all my uppers.

If it was up to me the MK12 upper would stay on a lower with an A2 buttstock, but only having one lower that gets used that's not really practical. I need a collapsible stock for my carbine uppers.

I currently only have Colt H buffers on hand, and after spending 800 GD dollars on a MF'ing pre-ban lower I'd like to avoid spending more money than necessary buying other buffers to test.

I'm wondering if any of you guys have run BCM MK12's on a variety of carbine buffers, and which weight you found to be optimal? I'm thinking H2 but without having it in hand to test that doesn't help me much.

Please advise on what has worked for you.

PS. What works for one 18'' rifle gas barrel may not be optimal for another. Gas port sizes vary manufacturer to manufacturer etc. I'm looking specifically for experiences with the BCM SS410 18'' rifle gas guns. Thanks.
ALCOAR
11-16-11, 21:50
Screw the people who charge that much for a preban lower to those behind enemy lines....I have never understood why fellow firearm owners screw other firearm owners.
a0cake
11-16-11, 21:54
Screw the people who charge that much for a preban lower to those behind enemy lines....I have never understood why fellow firearm owners screw other firearm owners.

Believe me bro, I did not want to buy it. I was pissed. But after coming across nothing but cast Olympic lowers and Colts with sear blocks / non-standard pins I was fed up. I decided to bite the bullet and go for it. Glad I have it now, but yes, I was angry.
ALCOAR
11-16-11, 22:04
In the grand scheme of things the ROI you'll eventually have with it will make it more than worth the $800, but like you it angers me greatly to hear about it occurring.

Glad you found one your happy with at any rate:)
Cameron
11-16-11, 22:14
Paul, the owner of BCM recommends an H2 or H3 buffer. I run an H3 in my BCM Mk 12 with the rifle length gas and the SS 410 barrel and it works perfectly.

Cameron
bp7178
11-16-11, 22:27
Paul, the owner of BCM recommends an H3 buffer. I run one in my BCM Mk 12 with the rifle length gas and the SS 410 barrel and it works perfectly.

Cameron

An H3 with a 18" barrel and a rifle gas system? Hmmm.

I suppose if you have H buffers on hand, as in more than one, you could steal some tungeston weights out of the left overs and make your own H2 and H3.
Cameron
11-16-11, 22:29
Or just buy one from BCM.

http://farm7.static.flickr.com/6137/5979963171_fd85de4137_b.jpg

Cameron
n517rv
11-16-11, 22:45
Or just buy one from BCM.

Cameron

Very nice rifle. That's similar to the next build I'm going to start working on. Out of curiosity, what kind of groups can you get with it and do you reload? I assume that's the 18" SS Ionbond?
Cameron
11-16-11, 22:49
Yes it is the SS410 with the Ion Bond coating. I don't hand load but I have shot many sub MOA groups with it shooting various brand of match ammo. The best results were with 77gr SMK Federal Gold Medal Match.

Having said that... my BCM Mk12 pictured above is for sale on this forum...

Cameron
Iraqgunz
11-16-11, 22:58
I would get the Vltor A5 set up. I think it will be perfect for your scenario. Multiple uppers on one lower.
a0cake
11-17-11, 11:32
IG, that probably is the best solution. I don't have much experience with the A5 system. I'm guessing the standard buffer would likely be the best. Or do you have another recommendation for a different buffer?

The lower will primarily be used on the following uppers:

18'' rifle gas
16'' carbine gas
14.5'' carbine gas.

Thanks.
jwfuhrman
11-17-11, 11:57
The uppers u listed will worked perfectly and benefit greatly from using the Vltor A5 system. I run one on my 12.5in SBR and one on my 3gun 16in Middy(before switching to the MagPul PRS). Both guns shot perfect and the 12.5 with A5 and the Surefire MB556K break, it's like shooting a 22 WMR.
Iraqgunz
11-17-11, 14:32
I am a parts whore so I actually have different buffers. I would go with the middle of the road one.


IG, that probably is the best solution. I don't have much experience with the A5 system. I'm guessing the standard buffer would likely be the best. Or do you have another recommendation for a different buffer?

The lower will primarily be used on the following uppers:

18'' rifle gas
16'' carbine gas
14.5'' carbine gas.

Thanks.