Viht loads for GM hardcast bullets to 50m

[dprees]

Any further progress on this old thread? I've just opened a tub of Viht N320 and I'm trying to develop a light .357 load for my Marlin, using 158gr TCs (both GM and home cast).

I've just tried 4.0gr in PPU brass, Fed primers, light crimp and the GMs averaged out 920 fps and the slightly softer home casts 940 fps.

I'd like to get the speed down a bit and it would be useful to know if anyone else runs a lighter load with the N320.

Apologies for the late reply--been away from this forum for a while.

I developed a light N320 load for the GM 158gr LTC I was happy with:
.357 case, Rem 1.5 primer, 3.3gr N320, COL 1.582".
21/Aug/13: 19C, 25yd. 10 shots: av: 807fps, mad: 10.4, es: 33, cov: 1.3%, sd: 11.8, ft-lbs: 228.
Elev: 33mm edge-to-edge, Wind: 26mm edge-to-edge.

David.

[Blackthorn]

Thank you for the reply dprees, useful to know how low I could possibly go down to. I'll have a tinker at some point.