Pressure signs with Magpro in my 7mag

06-11-2013, 09:33 PM Originally Posted by jht_ms Just got some 16ogr Accubonds and called Hodgdon for load data on several powders I have. H870, RL22, and Magpro. Their data for Magpro looked the most promising with start loads @ 68gr and going to 72gr with velocity figures approaching 3100fps. Started out with 3rds @ 69gr 3.385in COAL (confirmed bullet kisses lands at 3.395") and had sticky extraction and one peirced primer. This was the first time loading such a long/heavy bullet in thus rifle close to the lands. Figured I loaded too close and seated deeper to 3.375" and still had sticky extraction. I then backed the load down to 68gr and seated to a depth of 3.365" and still have extraction sticky enough that I have to slap the bolt with my fist to get it to come loose.

Went back and double checked everything only to realize I used magnum pistol primers instead of rifle, possibly causing a 2nd event. Duh!!!! So I started over, and with the correct components still have sticky extraction with starting loads of this powder. The can I have is about 4yrs old, so is it possible this is a case of Accurate's well known lack of QC between lots and inconsistent burn rates?

My question is:
What brass are you running?
The 7RM is notorious for differing case capacities between brands, if your brass is heavier than the brass used to gain those loads you're trying then that will be the cause of your sticky bolt lift.
Try backing off to 65gr's and shoot and see if the problem has ceased.

The COAL may be causing this, but if you have measured it accurately, it's doubtful it's the sole cause of your problem.

Cheers.

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