S&W M&P 15T

[Waylander]

I found a used one at what looks like a good price. I like the pinned on gas block with troy rails and BUIS. The only thing I don't like is the 1:9 barrel twist. I wouldn't be able to shoot heavier ammo right?

[Mac5.56]

https://www.m4carbine.net/showthread.php?t=53808

This is just one of the many threads that talks about your questions.