Ok, so public service announcement for 6CM guys using StaBall: remember, it's temperature stable
for a ball powder, it's not the same as H4350 or the better stick powders. Be sure to consider the temperatures you'll be shooting in when working up a load (if you aren't already)... because like a dumbass, I didn't consider it enough and it almost caught up with me.
I was used to Hodgdon H4350 because that's what I have the most experience with (besides StaBall), so loading with it, I never really considered the temps I'd be shooting in too much as H4350 hadn't ever really changed enough for me to worry about.
I had settled on a load at the beginning of March that was hammering at 2987fps at 61degF, kicked ass for a couple hundred rounds... well, same load at 80degF was showing spikes up near ~3100fps: pretty fucking fast for a 115 grainer (still hammering though). The brass looked ok, couldn't really find any obvious pressure signs, but the case heads were suspiciously more shiny than usual. I decided to shoot the last 5 rounds left from a batch over the chrono: 3 of them had an average of ~3020fps (fast for a 115, but fine by me), but 1 was ~3050, and 1 was 3098fps!
Ran the brass though the prep process and when I started to prime I could tell I must've been running some pretty high pressures because 10-20 of the primer pockets were loose enough to where I know they won't be holding on long, might be done after this firing, and this is only the second loading, almost still-new brass. fuck.
Anyways, I decided to work up a load considering the average temps I'll be shooting in over the next few months so I don't have to dick around with it all summer. Sadly, in Tennessee that means ~50degF in the mornings, to 100+degF for highs, it gets seriously ugly hot and sticky here a lot of the summer, average is 80degF.
New load is: 41.3gr StaBall, DTAC115, CCI200, CBTO 2.215" = 2852fps @ 62degF ES24* SD8*
* I know I could easily lower these ES and SD numbers, but this is just dropped straight into cases with a ~$50 powder measure, using a ~$50 scale, no trickling anything, powder for 100rds takes me about 15 minutes going slow... this is why I'm converted to using StaBall.
Sounds a little slow, but messing around with Strelok, that should put me at ~2896fps @ 79degF (TN summer average temp) and hopefully ~2950fps worst-case/sweating-ass-off at 100degF. Still plenty fast for a 115gr IMO, but enough cushion built-in so I shouldn't have to worry about pressure spikes. Plus, shouldn't toast my barrel quite as fast.
A happy-accident of all this is that I had never really chrono'd and looked at the lower load range with StaBall properly. The lowest I had run with StaBall was 41.5gr, and I landed on that load with a good guess that ended up hammering with an SD of 7 when I chrono'd it later (if only I was always so lucky in life). I did a mini-ladder from 42.4-43.4gr and was still faster than I wanted, so I did another one from 41-42.2gr. Biggest/widest node I've ever seen, I could probably pick anything between 41-42gr and be just fine, they were all within ~60fps, I picked what looked like the flattest of the flat spots.
I shot exactly one group at 100 then went straight to fun and steel at 400 because I was sick of load development shit, I'll take it out past 1000 hopefully this week. My bullet-jump still seems to be working, somewhere between .100-.120" of jump, no idea where the lands are and don't care. Felt like I pulled one... ;-)