Disclaimer for the newbies: Remember kids, putting any barrel shorter than 16" onto your AR Rifle makes it a Short Barrel Rifle and subject to registration and taxation under the National Firearms Act (NFA). So don't attempt this without going through all the proper steps!
There... Now with that out of the way...
I've decided to SBR one of my rifles, but I can't decide what length upper I want to use (read: "to write down on the Form 1").
I'm not interested in a 14.5" -- mainly because I'm not paying a $200 tax stamp to lop off 1.5". The 10" or 11" barrels look nice, but there's something that's just so.... about a 7" upper
I think the only thing keeping me from going with 7" is that I might want to toss on a suppressor one day, and I recall hearing claims that the round won't stabilize enough from a 7" barrel and will result in baffle strikes on the can. Any validity to this?
Also, both with and without a can, how much more blowback/fouling/etc. can be expected with a 7" instead of a 10" or 11"? Getting a gigantic face full of hot gas can make my interest in a 7" barrel DRT.