I'm thinking of building an AR pistol.  Other than accuracy what problems will I encounter if I use a 7.5 inch barrel vs a 10.3 inch barrel?  Same mfg, etc.  Will a shorter gas tube be less effective with the shorter barrel?

Huge flashes and major report with real short barrels like 7.
More wear and tear.


Super awesome fun

accuracy wont be affected, only velocity.....so elevation at distance and projectile performance ......shorter barrel actually suffers less barrel whip so technically stiffer more accurate and less variance in groups

the short pistol gas tube is as effective as any other gas tube . If the gas port is a good size it will work fine. Generally the closer to the chamber the gas port the more punishing the gas impulse will be cycling your system

Harsher recoil, and holy hell it's loud.

But a 7.5" is a lot of fun.

I have no issues with either of my 10.3" builds or my 7.5" there are a lot fewer silencer options for the really short barrel.

I had a 7.5", but didn't care for it. It just felt too short. It was on the loud side, and put out a pretty good fireball.

The biggest issues for me were that I could never get decent accuracy from that barrel. And when it started getting dirty, it would start tearing case rims when trying to extract.

I sold the upper and haven't missed it. OTOH, I've got barrels in 10.5" and 11.5", and both work much better.

I'm not usually one to rain on anyone else's parade in terms of people doing whatever they feel is fun, but I don't think the hearing loss and related injuries on the ultra-short 5.56's is worth it.

If you want something that will give you fewer problems, just get an 11.5