Barrel/Bolt combinations

[JMS11]

[LRRPF52]

Welcome aboard. The face depth has been reported both ways to me when I've asked, whether JP is using .124" or .136".

I would need to have them in hand.

For the guys that have JP's, if you could measure your bolt face depth with the end of the slide on your calipers, that would be great.

[JMS11]

Thanks for the warm welcome. JP's website says it is a type II bolt, which from my understanding means it should be the .136" depth, correct? So I would think the Liberty barrel, designed for a .136" bolt, should be compatible as long as both are within manufacturing tolerances. Or is the proper headspace such a narrow window that both the bolt & barrel could be "within tolerance" but the stackup causes it to be outside of correct headspace? This is my first rifle build other than standard .223 builds so I've never really had to worry about headspace issues before.

[LRRPF52]

Which barrel length are you looking at from Brownell's?

What are your goals for this build?

[JMS11]

I'm looking at the 18" barrel. I've read that the midlength gas system on that is overgassed so I'm planning on adjustable gas block too.

As for goals...well I want to eventually make it out to a 1000 yard range and see how it does. It also gives me a reason to get into hand loading.

[LRRPF52]

MLGS is fine, with the right port diameter for 18" Trying to get an 18" MLGS with a .094" tamed can be a pain in the neck.

I've been dealing with an Underground Tactical 18" MLGS with .094" port that even with adjustable gas, is on the ragged edge between bolt locks back, and failure to extract due to excessive carrier speed. It really needs at least an H3 buffer, if not something heavier.

If your main purpose it to shoot out to 1000yds, I would look at a longer barrel. At my altitude, it doesn't really matter as much, but down closer to sea level, you might want more speed. I'm not sure where you're at.