Gunsmithing Cutting the barrel

[USMC 0231]

I have had a few rifle barrels cut down in length with great results. One was 24in and had it cut down to 18in and recrowned to 11degrees and all that. My question is how close to the gas block can I go? I whave a great Armalite AR-10T with a 20in barrel. I was thinking about making it 18in. I will still have a little room before I reach the gas block but I dont want to mess with harmonics and/or function.

Thanks

Kevin

 

[Sonic Crack]

actually anytime you change the barrel length your changing the harmonics. Same can be said about brakes and suppressors. Not sure how close you can get to the gas block on an AR. I've seen AK's and Saiga's get cut back to right in front of the gas block and work fine with no other changes.

 

[WhiteDingo]

Depending on the gas port size, it may need to be adjusted to get enough gas while there's still a bullet in the bore. Generally, AKs are drastically over-gassed so chopping the barrel doesn't really hurt much. There are "dissipator" style builds that use a 14.5" barrel with the rifle length gas system.