Welcome to the forum, but you should make an intro post 
But my M24 does that, I think it's the receiver scratching the cylinder because you're pulling it at an angle.
Think about it, you're always pulling on the bolt handle alone so you're going to be pulling it back + to the right.
Some people think (me included) that if you put your thumb behind the bolt so it becomes a straight bolt pull it helps.
But my M24 does that, I think it's the receiver scratching the cylinder because you're pulling it at an angle.
Think about it, you're always pulling on the bolt handle alone so you're going to be pulling it back + to the right.
Some people think (me included) that if you put your thumb behind the bolt so it becomes a straight bolt pull it helps.