@CCT125US - I’ve had to do a similar thing for my 9x19s. The tightest chamber among them is in the P99c, so I use that barrel for the plunk test when I’m working up loads. The Berettas and CZs don’t seem to mind.
@CCT125US - I’ve had to do a similar thing for my 9x19s. The tightest chamber among them is in the P99c, so I use that barrel for the plunk test when I’m working up loads. The Berettas and CZs don’t seem to mind.
My current load is 3.6 grains of 231 with a 147 grain coated roundhouse at 1.14 oal which chronos right around 900 fps in a P30SK and around 920 in a P99, with very little deviation. Pretty accurate and clean, and close enough to full power carry ammo for quality practice sessions without beating on the gun unnecessarily. I had been using flatpoints but switched to roundhouse as both the P30SK and the P99 required the flatpoints to be seated deeper than I liked. Walter PPS didn't care though, go figure. I like the 147s both for recoil characteristics and for the fact that they impact a little higher and I like my point of impact to be at or above the top of the front sight rather than below it.
I finally got out the chronograph that had been gathering dust in the garage. Before I began my journey as a professional D class shooter in USPSA, I never really cared about power factors.
Much to my surprise the loads I had been using for the last 4 pounds of a proprietary powder blend all chronoed above the base line for minor power factor. Unfortunately one of my PCC's likes shorter COAL's and I ran out of my gift powder.
This is my first shot with this so tell me if something looks bad.
Bullet: RMR 124gr JHP Powder: WinClean 244 Primer: CCI #500 COAL: 1.075 UNLESS NOTED 10 SHOT STRINGS
3.3gr WinClean 244 SIG P320 X5 Legion 14 shot string
HIGH: 946 Low: 874 Extreme Spread: 72 fps
AVE: 902.8 SD: 19.39
3.6gr WinClean 244 SIG P320 X5 Legion
HIGH: 1055 Low: 993 Extreme Spread: 62 fps
AVE: 1,010.3 SD: 17.748
3.8gr WinClean 244 SIG P320 X5 Legion
HIGH: 1065 Low: 993 Extreme Spread: 72 fps
AVE: 1,029.3 SD: 17.83
3.8gr WinClean 244 GLOCK 17
HIGH: 1073 Low: 1033 Extreme Spread: 40 fps
AVE: 1,052.1 SD: 10.16 PF: 130.46
4.0gr WinClean 244 SIG P320 X5 Legion
HIGH: 1076 Low: 1048 Extreme Spread: 28 fps (NINE SHOT STRING)
AVE: 1,063.8 SD: 9.79 PF: 131.9
4.0gr WinClean 244 GLOCK 17
HIGH: 1118 Low: 1069 Extreme Spread: 49 fps
AVE: 1,087.6 SD: 11.93 PF: 134.8
I was shooting through the chrono at a USPSA torso with a 4 inch black sticker for a bullseye. 3.8 and 4.0 shot best in the Legion, group sizes were meh because I have presbyopia and if the front sight is clear, well nothing else is - they were 60% in the bull the rest circling. The Glock 17 has an RMR on it - one raggedy hole.
Shooting one right after the other really accentuates the differences in weight, the Glock was a little snappy at 4.0, the Sig just kinda sits there.
The SDs tightened up at 3.8 and 4 grains, and you said the accuracy did too. If it were me, I’d settle on 4 grains and call it good. As a general rule, you want to be at least 5 over power factor to account for differences in chronos and temperature changes.
Just some more data points for Alliant Sport Pistol:
147gr Blue Bullet TC 0.3555 loaded to 1.14 OAL using mixed brass"
Crimped to just remove bell
10-15 discard rounds loaded in between powder adjustments
CCI Small Pistol Primer
Sig X-five Legion
70 degrees F
Average FPS of 10 shots
Loaded on Dillon Super 1050 with powder baffle, SSI funnel and micrometer adjuster
Velocity measured via magnetospeed V3
3.0gr=860fps S-D:7.0 PF:125
3.1gr=882fps S-D:9.1 PF:130
3.2gr=897fps S-D:6.7 PF:132
3.3gr=926fps S-D:9.8 PF:136
3.4gr=939fps S-D:14.7 PF:138
Overall very satisfied with this powder. It's pretty clean, doesn't heat the gun up a whole lot, not smoky, meters very well, and seems to burn pretty consistently.