I have been getting very different MV readings between reloading sessions. I use an RCBS chargemaster and calibrate prior to each use. The rifle that has most recently shown this is a 300 winmag with 196 hammer hunters. In my first session after loading some rounds I averaged 3020fps. I reloaded a second group and averaged 3080fps. Today, after reloading a new set of rounds, I averaged about 2980. This has all been with virgin norma brass ran through a mandrel/chamfered&deburred and CCI250 primers. My CBTO measurements have also been very consistent.
Each time shooting was a separate reload process. I don’t believe it’s my chronograph as I haven’t seen this with some unknown munitions rounds I have. And each batch has an extreme spread of no greater than 40.
My best guess right now is that my RCBS chargemaster is off each time I do a new batch. The next logical step is to get another scale to verify this. I had a secondary scale that broke in a recent move but will be getting another this week.
Has anyone else had an issue like this? Is their something else that could be causing this? If it is my chargemaster what should I replace it with? I have looked at the A&D setups but don’t really feel like spending that much cash but if theirs no middle ground I’m not completely opposed to it.
Each time shooting was a separate reload process. I don’t believe it’s my chronograph as I haven’t seen this with some unknown munitions rounds I have. And each batch has an extreme spread of no greater than 40.
My best guess right now is that my RCBS chargemaster is off each time I do a new batch. The next logical step is to get another scale to verify this. I had a secondary scale that broke in a recent move but will be getting another this week.
Has anyone else had an issue like this? Is their something else that could be causing this? If it is my chargemaster what should I replace it with? I have looked at the A&D setups but don’t really feel like spending that much cash but if theirs no middle ground I’m not completely opposed to it.