A: If you are having trouble ejecting spent brass, that is a mechanical problem with the rifle, not a problem with the ammunition. However, if you are having trouble extracting cases (sticky extraction) from the chamber, then you are probably experiencing high pressure. My maximum load for the 6.5 RPM using the 140-grain Nosler Partition bullet was 66.0 grains of Alliant Reloder 25 powder. This load was working fine in my rifle, as extraction was easy (or normal), and neither were there any signs of excess pressure.
By you changing to the 140-grain Nosler AccuBond bullet, pressures will be different. Also, you do not specify what primer you selected. Please note that I chose the CCI BR-2 primer to develop my data, which is a standard non-magnum primer. If you are using a magnum primer, pressures will increase, and the powder charge will necessarily need to be reduced. Another factor may have to do with burn rate variances within powder lot numbers. For example, if my lot number of powder has a slightly slower burn rate than is targeted for this particular powder, and yours has a slightly faster burn rate, then your loads will produce greater pressures and usually higher velocities. This is a good example of why handloaders are generally encouraged to begin with reduced or “starting” loads, then work up carefully to maximum charges while watching for signs of excess pressure. This advice likewise applies every time a new lot number of powder is obtained. And last, perhaps your rifle is showing signs of higher pressure due to a shorter leade, tighter throat, tighter bore, etc.
Incidentally, using the Nosler 140-grain Partition bullet with 64.0 grains of Alliant Reloder 25 powder produced 2,955 fps, which more or less duplicates the factory load pressures and velocities.
You can read up to 3 premium stories before you subscribe to Magzter GOLD
Log in, if you are already a subscriber
Get unlimited access to thousands of curated premium stories, newspapers and 5,000+ magazines
READ THE ENTIRE ISSUE
October - November 2020