Home Forums Hunting & Shooting Handguns 240-grain SWCs and Unique in a 44 mag. - why the huge spread in loading data?

Gents,

Can someone explain to me why Sierra's manual #14 lists a max load of 7 grains for Unique powder under a 240 grain SWC (.430") while the classic light Taffin load is consistently listed as 8.5 grains Unique under the same weight of SWC?

Is the difference due to bullet hardness? If so, what's the threshold?

I have some 240 grain SWC's (.430") w/ a BH of 10. I'd like to load these over 7.5 grains of Unique for a paper punching & rabbit load, but not sure if that's "too light" or "just right", given their hardness.

I have loaded up some Oregon Trail 240 grain SWCs over 8.5 grains of Unique - they shot very well and recoil was pleasant, but I experienced a little leading downstream of the forcing cone. Given their hardness of ~24 BH I'm thinking that load was a little too light to seal out gas cutting.

Any input is welcome.

Thanks.