IMR 4227 burn rate is slower than tightgroup. You want faster powder in this type of revolver cartridge due to gap between cylinder and barrel which wastes gas when bullet jumps it. You have to have complete burn of powder in the cartridge case before bullet jumps the gap.With 4227 it may be wasted and still be burning after that resulting in blow by.
I used 4227 in 7.62 Ng cartridge and even with the gas seal I still had some residue of this powder in cases and barrel. It fired ok and for that cartridge 7 to 8 gr was ok. May be if I used mag primers it would be ok however I decided not to use it in these cartridges.
May be Kurgan or Drslav have more experiments with 4227, mine ended with 7.62 cartridges.
I have 4227 and it works just fine, though I still prefer TB as it burns cleaner and I seem to get better accuracy with it.
I also use 4227 in my Martini 32-20 Cadet (which also chambers "7.5mm Swiss Ordnance" and my various Swiss 1882 handloads).
I have an 1895 (production year) revolver with the "medium-strong" top strap, some of the earlier revolvers have a slightly thinner top strap, so what I provide, please take with extreme caution!
I get the BEST accuracy with between 2.8 and 3.3 grains of Trail Boss behind a deep seated .314" 100 grain H&N soft lead wadcutter in an untrimmed 32-20 Starline case resized in a 30 Carbine die. 2 to 3 inch groups at 15 yards is my average group size. I sometimes get tighter groups. Always fun outshooting the Glocks and other modern pistols.
I have "pushed the envelope" with up to 3.5 grains of TB, but noticed a very slight accuracy drop with the lead wadcutters. 3.5 grains of TB with a 100 grain wadcutter gives mid 900's fps. I can/would push my revolver to 1100 fps no problem, as I know the condition and capability of my revolver, but since they're not handing out awards of who can push the limits of the Swiss 1882, I choose to hot load for my Martini 32-20 (310) Cadet only.
Jethunter is now making 110-112 grain .314" bullets with gas check that would be great in our revolvers! I bought a batch of 200 from him, but have yet to fully test them. Once the winter is here, and I have less house maintenance, I will spend some time at the range testing them with various powder, brass (length and type), and primer combinations and report back.
Regarding 4227 again, I find that it really shines in my Martini 310 (32-20 reamed) Cadet fallingblock, which shoots factory 32-20 and all of my Swiss 1882 handloads, the later with supreme accuracy. The key with 4227 is a small rifle primer, even though performance with a small pistol primer is adequate (but dirty). I find that 4227 and a 100-112 grain gas-check bullet really sings at velocities over 1600 fps... and that is well outside of the 1882's "safety zone". I mark the rim of every +900 fps load intended for my Martini and ensure that the bullets are seated far enough out so that they cannot chamber in my Swiss 1882.
happy shooting,
K