It’s not that hard. No need to ruin a good barrel with a relief cut. I just did one with a brownells outside wrench and a Davidson barrel vise. Took a few whacks with a sledge, but it came loose.
If you don’t have the tools you don’t have the tools, but a Davidson or viper-style barrel vise and a brownells outside wrench will 100% do the trick without F’ing up the barrel. Didn’t have to soak threads or whack it or anything.
The RedSnake Tactical bottom metal will allow you to use a longer AI .300wm (or the MDT/Accurate .30-06) mag and fits the factory inlet. I have one on the way atm, but a buddy has one as is running full-length .280ai loads no prob.
Yeah get the adjustable gas block. Seekins makes a great one. If you’re going to suppress the rifle maybe spend the extra coin on the superlative. Allows the rifle to run cooler/cleaner/more reliably, and most quality ones are really easy to tune.