OK, let's get a little perspective here. First and foremost, there are only a very limited number of sources for bolt carriers. Given their reputation, S&W isn't going to source their carriers from folks who produce scrap. NO AR builder makes all the parts-even Colt.

That said, manufacturing tolerance stack does exist and can cause problems.

Now let's get down to brass tacks. Prior to retirement, there was, several years ago, a number of over pressure events with a certain brand of US made new factory ammo. In the usual manner, ammo company blamed firearm manufacturer, and vice-versa, leaving the firearm owners in the lurch. When we had the problem, I talked my employers into sending ammo & firearm to HP White Laboratories. They actually wanted several firearms, close as possible in serial number. It was determined that it was an ammunition problem. Faced with this, the ammo company exchanged all our ammo, threw in extra and covered both repair costs and the HP White fee. "Bad" ammo does exist and can happen from any source.

If anyone really wants a definitive answer for YOUR event, there's your method. BTW, you're talking $1200-$1500.

I'll also note that over 40 years, I've personally seen about 6 OOB events. I do know that about half were Colts, so those who claim it's impossible with any particular brand aren't entirely correct.