Hey got a question. I just built an spr style upper using the aero m4e1 upper and rail. When I installed the flash hider I had the upper secured in a vise block. I had to torque it pretty good to time it right. Afterwards I was enlightened that I should have secured the barrel itself while installing the flash hider so as not to stress the upper or risk shearing the index pin. So I am a little paranoid that I may have some how damaged the upper or barrel. Got no reason to suspect any damage, didn't hear any cracks or snaps. So can anyone offer any peace of mind? Thanks.

If the upper and lower mate correctly, you are probably ok. Years ago, i tweaked an upper so bad it wouldn't lock onto the lower.....at all. I then purchased a reaction rod.

Eta. Chances of you damaging the barrel are really slim. It's the upper that takes the abuse when torquing a muzzle device or barrel nut.

I've done that a couple times. I try to be cautious as twisting the upper is possible.

An easy solution would to buy barrel blocks, or soft jaws for your vise, and clamp the barrel into that.

All seems to be gtg. Functions fine. Just ordered the Magpul bev block .

I just built a set of barrel blocks, I can't get my 6.5" vise tight enough with soft jaws in them to get the barrel from turning, hardwood or even a section of 2x4 with a hole drilled through it cut in half will work for a set of barrel blocks, you just need to make sure you can actually reef a bit on the vise without throwing things off, mine vise is a 6.5" with a handle that is over 12" long, so I can get some pretty good leverage on it.