Buffer for 11.5 inch SBR.

General Firearms NFA
1

Finally almost have the pieces for my first SBR build. I have no plans to suppress for now. I bought this complete lower with an SSA trigger:

http://www.gandrtactical.com/cgi-bin/commerce.cgi?preadd=action&key=LWR-BCM

It dawned on me that the buffer/spring combo may not be ideal for the 11.5 inch upper I bought:

http://www.bravocompanyusa.com/BCM-11-5-Carbine-Enhanced-Lightweight-FLUTED-p/bcm-urg-11elwf-kmr10.htm

I’ve done quite a bit of searching online. Just looking to validate that I shoud change to an H2 buffer with carbine spring for optimal results? I’ve seen quite a few posts suggesting the buffer/spring on the lower I bought may not shoot as soft and reliable as an H2 with a carbine spring. Thoughts?

2

I have that same upper and run a H2 with standard carbine buffer spring. Runs smooth with everything I’ve tried in it, including .223 Russian stuff, m193, m855, and 50gr tsx. Zero stoppages and 4 oclock ejection.

3

Thanks. Forgive the dumb question as I’m still relatively new to this: Does the lower I bought have a carbine buffer spring? It doesn’t say anywhere on the description if it is a carbine or m16 rifle spring.

4

You have a carbine spring.

5

That’s what I thought. H2 buffer order is placed and I should break in the SBR in a week!

6

Hate to be the guy to do this, but look at the Vltor A5 system. A5H3 I have found works on everything.

7

^ He speaks the truth. I have no issues with a standard A5 buffer on a DD 11.5" barrel.

8

If you don’t have plans to suppress it anytime soon, you will be happy with an H2 and carbine spring. Ran this same set up for years and years. Shooting back to back same 11.5 BCM upper with 2 SBR lowers without the suppressor on, A5H3 setup and H2 car, I would say with the cost to switch it, is minimal felt difference between the 2. A5H3 May be slightly softer, but I couldn’t tell much of a difference between those spicific two. I recently swapped to a A5H4 with e carrier and standard bolt. But that is my setup for a mainly suppressed SBR.

Rock the H2 carbine setup. It performs and runs 100 percent in the 10s of thousands of rounds I’ve put through that setup.

9

H2/ Sprinco blue spring is tried and trued. I run almost the same setup except I run the heavy barrel. It runs well with cheap Wolf ammo all the way up to the good stuff both suppressed and unsuppressed.

10

I run an H2 with my BCM BFH 11.5 and it has been great.

11

H2 will be fine. If you suppress it, you will need to get an H3 or you will have intermittent failures to lockback.

12

My recommendation as well. However, I’m currently running the A5H2 as it’s not yet suppressed. Not one hiccup so far. Once I put a can on it I’ll go up in buffer weight.

13

whould the sprinco blue spring work on a 7.5 300blk and a 10.5 5.56 both suppressed and unspressd

14

My 11.5" BCM ran no issues with standard carbine spring and H buffer, but recoil was pretty sharp. I skipped the H2 and jumped straight to H3 (keeping the carbine spring). Smoothed it right out, and zero hiccups (in my gun). I wanted to tame it without using a comp (I don’t really care for them), and it did the trick. I’ve shot a mix of WWB 55 gr, AE223 62 gr (mostly this), some junk PMC bronze 55gr, and Federal TRU 55 gr with no malfunctions in this setup and been very pleased. All have been unsuppressed with a standard A2 flash hider.

15

ill have to take the buffer into consideration.