SBR'ing a 9mm

[p7fl]

I recently purchased a Colt 9mm AR (6951). I believe it is finally working reliably. The Rifle has enjoyed multiple trips back and forth to Colt, and 2 different smiths locally etc. But I finally think it is going.

I would like it to be an SBR. All my rifles are short and less weight up front is preferred.
This is a dedicated game gun, USPSA and Steel.
Before I start on the paperwork……
A. Is there more work that has to be done to the rifle other than shortening the barrel once the paper is approved?
B. Are there any problems that can be anticipated?
C. Would it make more sense to shorten the barrel or purchase a short barrel?
TIA
jon

[Bret]

jon, unless you already have the tools to shorten the barrel and rethread the muzzle yourself, definitely purchase a new short barrel. Once you sell the original, it will most likely cost you less than the tools or paying someone else and you'll end up with a better product.

BTW, what was the problem with your rifle? Are you using Metalform magazines?

[p7fl]

Bolt catch would lock up after about 15 rounds. Tried fixing it, tried replacing the part. Went back to Colt. New rifle rifle arrived with same issue. 2nd Colt went back and now seems to be working.
Two other people mentioned on M4 having the same issue with the 9. Colt never gave me a straight answer as to what they did to repair the issue.

[diving dave]

I sent mine to adco and had it cut back to 10.5 and threaded... added a 7oz buffer and she runs great suppressed or in suppressed

[Bret]

Colt never gave me a straight answer as to what they did to repair the issue.

That's annoying. It funny how if you have a gun that's not running reliably, the manufacturers want you to provide as much detail as possible to help them figure out what's going wrong (which is understandable). However, they hardly ever return the favor by providing details to the gun owner as to what they did to repair the rifle.

BTW, my recommendation to swap barrels is based on the assumption that you have the tools and knowledge to swap out the barrel yourself.

[zephyr]

I also had ADCO cut down my stock 6951. I would have just bought a Colt one but they were unobtanium at the time. I added a heavy buffer and she runs great with and without my suppressors.

[usmcvet]

I’d say buy a factory Colt SBR upper or bbl assembly. I’d get the complete upper. I had ADCO shorten a CMMG .22 upper for me. He did great work.