The 1/7 twist is fine for 50-55 gr bullets, however the chrome lined PSA/FN barrel isn't known for accuracy nor is most FMJ ammo. Usually XM193 runs about 1.5-2" groups I don't know anything about your ammo.
I like 77gr bullets in the AR but have shot a ton of 50 gr NBT's as well. 1/7 is my favorite twist for the 223 especially in a carbine.
