Buffer weight for SBRs?

I will have to shoot it again this weekend and look at the ejection pattern closer. I will give up mild 223 to gain durability with 556 loads.
I shot a verity of ammo with and without the can.
Even AE 223 and 55g 223 pressure handloads never got the the right of 2:00. Even without the can.
As one would expect the higher pressure ammo, can, etc pushed things to 1:00.
Mk262 was 1:00 with and without a can.


Regular Member
Keith, that's seriously overgassed even without the suppressor. I'd be concerned about long term durability with that setup, as it's beating itself pretty hard.

Personally, I wouldn't even bother trying to fix that with heavy buffers, I'd go straight to some sort of gas restriction, like an adjustable gas block, or bushing in your current gas block. Does that rifle have a low profile gas block under a handguard, or something like an A2 front sight block?
It has low pro gas block under the handguard. I think those were some sort of special material gas block to survive 10" 5.56 suppressed abuse right?
I ordered that upper December of 2015 if anyone has a timeline on DD MK18 gas port sizes. This is why I have never shot it much.


Regular Member
I'm not sure on the "special material"; as a machinist that doesn't sound right to me, but ?

Regardless, there are a number of good options for replacing that with a low profile adjustable gas block, which is your best option for fixing the gas issue, and one of the few options that's not a band-aid. My preference is something like the Seekins adjustable blocks; set it once, lock it down, and forget about it. I'm not really a fan of the "click adjustable" blocks, and don't have anything good to say about the Superlative "bleed off" system.
Would guess SLR, they OEM the DD low profile gas block already.

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Update, the adjustable gas block was a temp fix from DD. They are now making new barrels for us with the correct size gas port for suppressing. At no cost to us I may add. I’ll be happy when this is all over but DD came through with some outstanding customer service.
I'm guessing it also varies based on the ammo being used, but from what I'm see from most the lightest weight buffer is a H. I have two 11.5 AR pistols which both use H buffers and so far I have shot a bunch of 55gr and 62gr with no issues. Understanding not to go below 10.3-10.5 length otherwise you might run into reliability issues I'm also seeing a lot of you guys lean towards using H2 and up. No experience with suppressors due to where I live so that side of things is completely foreign to me.
Out of interest but does anyone use an H3 for an unsuppressed 10.5 or 11.5? Also, anyone have any experience using the Geissele Super 42 with a 10.5” or 11.5”?