These are problems I have never experienced...AHH...Not so fast! You say 55 grain bullets in a fast twist 223? There can be a problem.
A fast twist like 1 in 7 is meant for longer heavy bullets in the 70 grain class (69, 75,77, etc). They need that fast of a twist rate to stabilize in flight. When you shoot the lighter weight bullets in them the centrifugal force from the rate of spin can literally explode the bullets before they get to the target.
It all depends on the quality of the bullet and what it was designed to withstand in RPM's. Hunting bullets are not a good choices but Varmint bullets might be. Only testing them will prove it one way or the other.
This is not my theory but my experience. I have a 1 in 8 AR in which I tried to use hunting 55 grain bullets. They literally never made it to the target in one piece. Slowing them down helped but changing to a Varmint bullet helped more. The accuracy did not anywhere match what the gun would do with the heavier bullets designed for the faster twist rate. Using 55 grain bullets was a waste of time and reloading components for me and my gun.