I was tearing down my new 453 to clean all that grease they put in it and noticed that there is a difference in the 452-453 bolts. The 452 bolt body is round with a slot milled in the bottom.- The 453 has the right side milled flat-this is for the trigger function I assume/guess - but there is enough difference to make them not interchangeable. heres a picture [Linked Image]

Last edited by bbgun1; 03/01/10.