[admiral]

reloading some bullets i cast from wheel weight lead for 45-70, they are 340 grainers. I've always loaded jacketed bullets in the past and am wondering roughly how fast i can push these before i start loosing accuracy or leading up the barrel. figured i'd start with 37 grains of re 7 and work from there. don't have exact data for this bullet weight but it is well below max judging from data for 385 grainers. should be in the neighborhood of 1500-1600 fps.

MY QUESTION - is that too fast for ww alloy.

[444]

1500-1600 ?
No, not at all.
There are a number of factors that effect whether or not you will get barrel leading; condition of your bore, the alloy used, the lube used, whether or not you are using a gas check, the bore/bullet fit, what powder you use....... Velocity is only one small factor. If you have everything right, you could push a cast bullet as fast as any other bullet in the .45/70. But, 1500-1600 is not pushing things at all.

[GooseGestapo]

Depending on the Powder you use, alloy used, and lube, bullet diameter, you should easily get 1500-1600 w/o serious leading.

I used a Lee .458"-340 plain base in a Marlin 1895 .45/70. I was able to get up to 1,900 fps using RL-7 before accuracy really fell off. Best accruacy was at around 1,700fps, but my particular mould was just not as accurate across the board as a 405gr plain base-H.P. mould I had. The bullets were sized to .460" and the 340 cast at actual .458-.459 so was just not "happy" in the Micro-Groove barrel like the 405gr was that came from mould at around .461".

Wheel weight will work real good, just don't expect lots of expansion, as if you really need any.

I recommend you size to .459 or .460" and use 50/50 Alox lube.

(and Exedrin for the headache/shoulder aches after you fire a few if faster than 1,500fps).