I need help, Im new to 3gun and newer to semi auto shotguns. I came across a used Rem1100tac4 thought it was the answer to my needing a gun problem (I think I paid to much). brought home, cleaned it up added daves metal works easyloader. Everything works on the bench. I take it out and shoot it Slugs great, buck shot great, target loads no good. I tried three different brands fed rem Winchester. it might fire 2 or 3 rounds, most often just one round then the bolt locks open. Is this an ammo problem that Ive read about, or is something else going on. Thank you for any input Greg