Thoughts on an 18" barrel

[customcutter]

I'm making an 18" barrel from a blank. I was wondering what your thoughts are on length of the gas system, for the best functional use. Mid-length or rifle? Also size of the gas port? I'll probably use an adjustable gas block. I'm thinking rifle length and .074", but would like some confirmation.

If anyone has any links for barrel profiles they would be welcome as well. I'd like to make it as light weight as possible without sacrificing too much accuracy. I'm also planning on using a forged slick-side upper, and making it a side charger so lighter might be better.

[ricsmall]

CC

mark at precision uses an intermediate gas length. What that length is I don't know but if u give him a call I'm sure he'd help u out. Maybe someone on here has one and will chime in.

Richard

[Klem]

Mid length gas ports are the standard for 18" barrels. In the Grendel the typical gas pressure at the port (10") is 17,000lbs (Ref Quickload). You need a minimum 4,500-5,000lbs to cycle an AR reliably with the lightest buffer, 3oz. 17,000lbs will cycle all buffers, including A2 fixed-stock buffer weights, 5.2oz and H3 carbine, 5.4oz.

I will let others comments on the port size.

Lilja has blueprint profiles online to help customers decide. Blueprints are intellectual property and in your shoes I would ask his permission of you plan to copy their work. The Lilja's are nice guys and would welcome your call.

[Flyguy11]

Gas port size on the Satern Barrel from Brownells is 0.93"; I emailed Satern (nice folks). Other members have suggested that it is way to big (over gasses) and to use an adjustable gas block; I'm going to be using Syrac Ordnance gas block. The suggested gas port hole size I have seen here on the forums is 0.76" for 18" mid-length system. I am very new to the Horde so please DO NOT take this as the gospel.

[AZ. Old Guy]

My Lothar Walther barrel came with rifle length gas. I've had no problems.