10 mm loads for major power factor

[jmbaccolyte]

I'm sorry if I misunderstood, I thought your statement was that a major power factor (165 pf) .40 S&W load was at or near the top of the cartridge's performance envelope and I responded that the top load listed on Hogdgon's website is 208 pf. Please excuse me if I sound churlish, I'm getting old and tend to get cranky about nap time.

I'm certain that some of the guys here have run .40s at 1.26" OAL with 10mm loading data and can answer your other questions. As for rounds going "pop" (case failure?) I suggest using new or real "once fired" cases for full power loads. Happy Trails.

Edited June 6, 2015 by jmbaccolyte

[dsb]

No, you're fine... looking up the load data you quoted showed me that there were more .40 loads that comfortably made major than I had first thought, but at 1.125" OAL.

Yes, my 'pop' was a case failure, it was a case that I accidentally picked up at a match, or someone picked up for me, that hadn't been fired through my gun. I wholeheartedly agree with your recommendation of "using new or real "once fired" cases for full power loads", which is why I have always started with new brass and only used stuff that was fired through my gun. This is why the whole .40 is cheaper than 10mm argument doesn't work for me. $157/K vs. $162/K for brass doesn't motivate me to run .40, especially if I have to load it long to make it feed right.

"I'm certain that some of the guys here have run .40s at 1.26" OAL with 10mm loading data" I seem to remember running mine at ~1.20" OAL with a 200grn projectile, and wishing that I could go longer. If you can get to 1.26 with a .40 that might be OK, but if you can't, and you're using 10mm data, might that potentially cause a problem? I'm thinking it at least contributed to my case failure, especially since major was 175pf back then.

The funny thing is that I'd have preferred to run 10mm back then, but I was told I couldn't because Strayer hadn't made enough 10mm guns for the Limited cutoff/homologation. Somehow, Jim Fairhurst managed to use a 10mm at nationals, but I don't know what gun he used, he wrote an article about it in Front Sight back in '99.

[jmbaccolyte]

Great. My Tanfoglio Match (not nearly as expensive as it sounds) in .40 lets me run pretty long OAL with 180 grain Bayou and BBI coated bullets, if I use the 10mm mags. But almost all of my loads are cream puff (minor pf) or medium (major pf). I run them long just so I can switch between minor, major and hot loads easily. The brass I use was picked up from law enforcement range qualifications that used Berretas and H&Ks, so true once fired.

Of course, YMMV.