Lead vs Bismuth in reloading

[Matt Valinsky]

Originally Posted by Pete Lester

Bismuth delivers higher pressures than lead, because with equal weight there is more bore scrub (friction) as the same weight of bismuth has a larger volume.

An old rule of thumb is you can take any lead recipe and substitute the same VOLUME of bismuth and get similar results. If you should do that you are in untested territory but I have never heard or read anyone who had a problem by doing this.

If you substitute lead for bismuth in a tested load in theory there should be less pressure, given the very low pressure of your chosen bismuth load substituting lead may lead to bloopers and squibs especially in cold weather.

I thought it had something to do with volume but never connected the friction aspect.

Thank you for the knowledge.

[J.B. Books]

Originally Posted by Matt Valinsky

I thought it had something to do with volume but never connected the friction aspect.

Thank you for the knowledge.

Just don't substitute the same VOLUME of lead in a bismuth recipe and expect lower pressure because you would be increasing the weight of the shot charge.