The only steel match that I have shot out of this gun was the 75 grain stuff. Never the 55. The barrel is a Rainier Match grade 18" 1/8 223 wylde chamber. The barrel is awesome. Shoots sub MOA with good ammo all day. I thought it might be the comp so I removed it and shot a couple more. Same result. I even shot rounds out of two different boxes. Shot some Federal 223 55 gr, PMC X-Tac 55 gr, and some Black Hills 77 grain. All shot great. I am at a loss. The only thing it could be is the ammo. I am going to contact Hornady and give them the lot numbers off the boxes. Hopefully they make it right. Otherwise I am out $300 in ammo.