Eye,
I would be cautious taking any unconventional approaches in the hope of improving your groups.
What will tighten your groups is buying a better barrel, range time/practise, and load development. Those three things are guaranteed to improve your situation.
What could tighten your groups is checking your screws. bedding, squaring and buying better triggers and scopes etc, but there is no guarantee. What you already have might be doing a good job.
As for barrel twist - you do not need a slower twist to achieve 0.55MOA repeatable out of an AR - 1:8 is the standard and perfectly fine. You just need a good barrel, repeatable scope, decent trigger, and a good bench rest.
As for bullets - it depends on the barrel and what you are using it for. TNT is great for hunting but the worst performer for precision in my barrel. I prefer 120NBTs and ELDs. The barrel will tell you what it likes.
I don't glue or square uppers - you don't need to do this to guarantee accuracy. It might improve things if the parts are compromised from the factory but there's less chance of that if you buy quality.
I would be cautious taking any unconventional approaches in the hope of improving your groups.
What will tighten your groups is buying a better barrel, range time/practise, and load development. Those three things are guaranteed to improve your situation.
What could tighten your groups is checking your screws. bedding, squaring and buying better triggers and scopes etc, but there is no guarantee. What you already have might be doing a good job.
As for barrel twist - you do not need a slower twist to achieve 0.55MOA repeatable out of an AR - 1:8 is the standard and perfectly fine. You just need a good barrel, repeatable scope, decent trigger, and a good bench rest.
As for bullets - it depends on the barrel and what you are using it for. TNT is great for hunting but the worst performer for precision in my barrel. I prefer 120NBTs and ELDs. The barrel will tell you what it likes.
I don't glue or square uppers - you don't need to do this to guarantee accuracy. It might improve things if the parts are compromised from the factory but there's less chance of that if you buy quality.