Short throat ar15

[SPRING]

I whould like to shorten the throat of a AR barrel to keep the bullet from jumping .130". What is the process for accomplishing this?

 

[rayjay]

Buy a new bbl assy with the chamber cut the way you want. It would be possible to remove the bbl from the bbl extension and set the shoulder back. Getting the gas port oriented correctly will be a bit of a fiddly problem. Coming up with a gas tube the correct length will be the bigger issue. Buy the time you get the problems worked out you could have just bought a custom bbl assy.

 

[Rustystud]

Throats on semi autos are cut long so several different ammo manufactures rounds will fire effectively without jamming. Semiauto rifles are not known to be as accurate as bolt guns. That is not to say they can't be. You can have a AR type rifle chambered by a competent gunsmith with a tighter chamber and shorter throat depth. But you will have to keep it clean and load your ammo for that specific chamber and throat. Remember ARs are designed to being fired multiple times in field conditions. Loose long throats tend to be more dependable over a course of shooting conditions.
Rustystud

 

[dtech]

Actually, removing the barrel-extension and shortening the chamber is not that tough. If removing .0625" from your throat is enough, moving the gas-tube that much further into the key is not a problem. The furthest I have gone, and experimented with was a set-back of about .090", and the barrel shot fantastic with the stock gas-tube and key.

 

[Clark]

My Bushmaster V-Match has a throat so long that a 70 grain bullet just barely seated into the mouth [way way too long to fit in a magazine] cannot touch the lands.

This rifle can shoot 1.4" very often, but the best it has ever shot is 1.05" 5 shots at 100m.

I think if I could touch the lands, I could do much better.

As it is, I don't bother shooting that rifle.