10.5 barrel and buffer recipe

[Doc. Holiday]

Hey guys I'm am doing my first build and I wanted to get your thoughts on what recipes you have found to be successful. Here are the parts I am going to use (concerning gas)

BCM BCG
Geissele gas block
10.5 Rosco bloodline barrel - gas port size .073
Carbine length gas tube

So my question is, what buffer spring and buffer do you use that you have found to be reliable or what would you recommend that I start with?

Thanks guys!

[Outlander Systems]

Depends on various factors, including ammo.

TLDR; Heaviest buffer that still locks back the bolt on the last round.

[dmd08]

I ported my 10.5" at .067 and it still runs unsuppressed on a regular carbine spring and H3 buffer. I do think I'm on the edge of reliability with that combo unsuppressed. I don't shoot pmc or any steel case ammo and so far its been ok. I typically shoot it suppressed though and it runs just fine like that.

Will you be using a suppressor?

I'd try an H2 and go up to H3 if possible. I think the H2/sprinco blue is a popular recipe but I've not used the blue spring yet.

[HeruMew]

I run an H4 in an over gassed 11.5" PSA upper. If it's ported to .73 H2 or H3 should be good for M193 and most other rounds. H2 would probably be more applicable to your weaker .223 steel cased.

[gaijin]

H2 with m193 in two guns.

[Doc. Holiday]

Right on, thanks for the input guys. I want it to be reliable with as many ammunition types possible. I NEVER run steel cases unless it's in my AK's. I will primarily run m855 and m193.

[Doc. Holiday]

And I will be running a suppressor eventually, but I'm about a year out from that.

[HeruMew]

And I will be running a suppressor eventually, but I'm about a year out from that.

With such a ways out, I would pick up an H2 and H3. When you get the Can, get an H4, just in case you need to increase that dwell time to avoid feed issues and such.

[Lincoln7]

I run an H4 in an over gassed 11.5" PSA upper. If it's ported to .73 H2 or H3 should be good for M193 and most other rounds. H2 would probably be more applicable to your weaker .223 steel cased.

Woah, H4? I'm not aware of anything more than 3.
Unless it's the Vltor A5 system...

[HeruMew]

Woah, H4? I'm not aware of anything more than 3.
Unless it's the Vltor A5 system...

PWS Offers H4s in Carbine.

It's on a pistol, I have tried the A5 H4 with it, and had great results. But wanting a brace, I couldn't keep it a plain buffer tube. So, I swapped them out to the H4 carbine. Until I SBR a lower one day.

A couple other companies have H4s, but they're not common. My PSA was so over gassed it operates with Wolf/WPA Steel with an H4 both A5 and Carbine.

I need to remove the FSP and put in a plug if I want to tune it down more.

ETA: I should add, that when I started out with an H1, I saw some pretty early marring on the polymer tail cap. As I switched it heavier and heavier, I noticed the dwell time got a little bit smoother and a lot less jumpy in the shoulder pocket.