Not into BPCR......yet. Just hunting and side match stuff. Have a Sharps 40/70 SBN and contemplating a mold throwing a 350-400 gr bullet. I kind of like the RCBS design but MLV said something about too much nose bearing surface. So that leaves the Lyman and Saeco designs (I like the looks of the Saeco 370). The Snover types don't look like optimum for hunting but maybe cast 1:20 it wouldn't matter on deer.

Appreciate input and especially the conventional wisdom on commercial designs with respect to nose bearing load.

Yellowhouse
Lyman has two flatnose .40 cal molds. a 240 grain #403169 and a 400 grain #410655. And if you want a custom mold, Steve Brooks will make a flatnose anywhere from 300-450 grains, it looks like a Lyman Postell wth a flatnose.

Yellowhouse: I've gone thru the learning curve with my 40-70 SS. Your 40-70 SBN is somewhat different. It will be a challenge to load cartridges for this rifle, but not impossible.

First, you need to know your bore size. If you have an original rifle, your bore is probably .403 inches. Modern makers of 40 caliber single shot rifles for the most part are using a bore size of .408. this of course will make a big difference in the selection of dies and bullet molds.

You can save yourself a lot of wasted effort and expense by first calling Buffalo Arms. Their web site is www.buffaloarms.com (http://www.buffaloarms.com) . They are extremely knowledgeable and helpful. They can supply you with brass, dies, molds, and everything else that you will need.