Make sure the rail you want has an ID greater than 1.5”. Problem solved

My local suppressor shop and all things NFA (Innovative Arms) charges $20 for a pin and weld. Not sure about removal, but I was in there one time and they had probably 50 Colt 10.5” uppers with pinned cans on them that some private security company (Nuke plant I think) was having them unpin. So it’s definitely doable if the care is taken. I would worry about the can surviving and go ahead and chalk the barrel up as scrap (or cut down to 7.5”).

I would love a GP7 for a 300BLK build and my 308 bolt gun.

Filing a form to take an SBR out of state is ridiculous. Bad enough they know you have the gun, but knowing where you’re taking it? Jesus. Whyyyyy