Yeah, I was gonna say thats what I think it is too. He might have stored the bolt incorrectly... I put the pin in wrong once myself when I was replacing the rammer and the bolt and its kinda easy to mess it up if your not looking.
Pull the pin out, remove the bolt, and push the rammer all the way back with a ball point pen or something. A small screwdriver works too. Then replace the bolt in the proper groove. Also, replace all the o-rings on the rammer, especially 011. Lube it up and try again and let us know.