Any tips for accurate 357 subsonic loads for a Marlin please

[Old phil]

Undecided between 38spl and 357cases. Rifle is moderated
Thanks

[davegee59]

I use 7 gn Viht 320 for 357
5.9 gn virt 320 for specials and its a nice crisp load and burns quick and clean

[Old phil]

Thanks for that

[Black Beard]

I use 3.5 gr N320 and a 158 grain RNFP lead bullet for target shooting. I haven't chronoed it but I guess it will be doing about 900 FPS in a rifle.

General rules for quiet loads:

The aim is to have a high initial pressure, to minimise the amount of powder used and to take as much energy out of the propellant as you can before it leaves the muzzle. This means you get less gas at less pressure in the muzzle blast, which is quieter.

Use a minimum case capacity. If you can load bullets deeper than normal into a 357 case then you get higher initial pressures. If not then use 38 cases.
A crimp will also increase initial pressure. So will softish lead bullets as they upset into the bore better. Heavier bullets will be better at taking energy out of the burning gas. Use as fast a powder you can find (N310 is good but a pain to work with so N320 is nicer).

BB
.

[thisisdonald]

Great info there BB, thanks. Im using Tin Star and Bullseye with really light loads that I cant remember right now, with 240gn flat nose in a .44 mag case.. not sure about quiet, but they are really consistent.. the bullseye and tinstar are quite bulky and are really consistent in my redding powder thrower.

[Old phil]

Thanks very much- never realised that
I have N340 and Unique.
4.8 of the latter with a 158 cast TC in a 357 case gives a nice tight group but I think just on the threshold of going supersonic. 4.7 will probably do it
I also have N 310 but I suspect that might do best in a 38spl case?