It all started with wanting to do a simple muzzle device swap from the AAC flash hider that came on their 300BO 16" upper. Installed upper Installed upper on Magpul Bev Block in vise and of course using a wrench crushed the flats because they designed this area too thin to even have flats on it. What were you thinking AAC, for designing it so thin where the flats are to begin with?
So I take out my AAC flash hider tool. I crank counter-clockwise and CRACK! WTH? I thought the upper cracked so I took out the carrier from the rear of Bev Block and removed upper. Nope, the feed ramps never moved due to the Bev Block. Then I look inside the handguard and the entire barrel obviously turned as I can see the twisted gas tube. Crap, time to disassemble upper to see what the heck is going on. Well it turns out that the darn muzzle device is on tighter than the pressed on feed ramps to barrel mating surface can handle. There is no way to hold the barrel without damaging surface except at the gas block, so that was what I did next, using a crescent wrench to keep barrel from turning while I attempted to break loose the flash hider. I'm determined to get it off of there at this point as the gas block already received witness marks when it hit the inside of the handguard anyhow. The darn flash hider was on so tight that I had to use cheater bars on both my breaker bar on the flash hider tool and a cheater bar on the crescent wrench! You've got to be kidding me?!?! finally broke it loose and little to no sign of locktite, so some jerk cranked it down to probably 250 foot pounds! I'm not kidding, this is how tight it was! the barrel was actually twisting/flexing!!! I stopped short of using a blow torch on it and used a commerical grade heat gun to heat it up. It took everything I had to get it to break loose and I lift weights 5 days a week! the AAC handguard nut was also excessively tight and it's a wonder the threads didn't strip out when they assembled it.
I'll be calling AAC regarding this as I feel they owe me a flash hider, gas tube and gas block. At least the upper receiver is not damaged. I am still not sure what to do about the barrel and feed ramps turning. I wouldn't think that should happen. Thoughts?