Tom I was out with the 250 R this last couple days and noticed with 5 in the magazine and one in the chamber the darn thing rattled. I've had that happen in the past and the solution was to remove one from the magazine. Didn't try it on the 250 R.
As a side note, my buddies 300 R had the lever stick halfway open after he got his buck on Thursday. So the pre-mils have their issues once in a while too I guess.
