I just received a new KRB in the mail. I was tinkering with it and relubed the breech plug. I decided to fire a Winchester 209 777 primer to "clean" out the plug but when I seated the primer, the gun will not fire. It dry fires fine when the primer is removed. It appears that the primer is "pushing back" on the block and the block is blocking the hammer from engaging when the trigger is pulled. When I drop the primer straight into the breech, half the primer is sticking out. Is that normal? Is it an issue with the 777 primers or perhaps the breech plug?