That beauty on the right is Berry’s Bullets .458 diameter 350 grain RSFN copper-plated bullet. It’s recommended for target-shooting and plinking up to 1700 ft/s muzzle velocity and they cost about the same as my typical 308 or 8mm hunting bullets. The core is not that hard and the plating not that tough so the bullet will distort or strip, I guess, beyond that. So, my objective is to develop a load that will give ~1700 ft/s out of the long (32 inch) barrel of the BC. A number of powders are suitable: Unique, H4198 and a few others. The problem for me is that much loading data is either more whimpy than that or far more brisk than that. I will have to experiment. I will also do expansion testing to see whether this load will expand on logs indicating usefulness on deer despite Berry not recommending these bullets for hunting. I figure if a bullet is soft enough to fail at 1700 ft/s near a rifle it will fail in a deer too. Lots of deer are taken with pure lead or hardened lead cast or swaged bullets and I doubt the thin plating of copper will make much difference.
I weighed ten bullets out of a bag of 100 and found the mean mass was 349.36 grains with standard deviation of .43 grain. The extreme deviation from the mean was 0.66 grain. That’s not as good as some jacketed bullets but at about half the price they should be just fine and probably better than cast bullets. A few of the bullets had small dents in the plating probably from shipping and handling.
First step is choosing a seating depth. BC is reputed to have a short throat but being a single-shot I don’t need to crimp on that cannelure or crimp at all and I will try seating out to the rifling right away. My loads will be far from maximum for such a strong action. I obtained some Starline cases. They don’t look as good as Winchester cases but they are cheaper so they are worth a try. They have ugly looking flash-holes seen from the mouth of the case but I made no attempt to true them. I made a tiny flare to avoid shaving copper and seated a bullet far out. I gradually seated the bullet deeper until the dummy round fitted easily about 0.050 inch from full insertion into the chamber. I then closed the action to seat the bullet further. LOA was 2.432 inch! That is a short throat! Typical loading data is for 2.55 down to 2.525 inch. I repeated the process, and noticed that I had judged chamber insertion by the extractor, not the chamber itself. Choosing smaller steps I was able to close the action easily at 2.461 LOA with rifling marks showing. The cannelure is just below the mouth of the case. This short throat will likely limit my velocity at the top end with 300 grain JHP just because of charge weight…
Lyman’s 45th cast bullet reloading manual lists 292 grain bullets with 18 to 20 grains of Unique and 385 grain bullets with 14 to 17 grains in an 1886 lever-action. Interpolating suggests 15 to 18 grains of Unique should work with a 350 grain bullet and give about 1500 ft/s in a 26 inch barrel and a bit more in a 32 inch barrel. I would risk a bit more powder given that my BC is much newer than 1886… The chronograph is my friend.
Those are scary loads… The charge only fills about ⅓ of the case so a double charge is easily possible. So, I weighed each charge and seated a bullet on it before I could accidentally add more powder. I labelled each case with Uxx.x to indicate the charge.
Next, I’ll load H4198. Hodgdon, who makes the powder, shows a “Trapdoor” load of 32 grains of H4198 giving 1483 ft/s for a 385 grain bullet out of a 24 inch barrel. It’s a very mild load at 14700 CUP so I should be able to use 35 grains in my BC with a 350 grain bullet. They show up to 54 grains behind a 350 grain bullet near 2100 ft/s for “lever actions”. Hornady published data for their 350 RN bullet, 34.7 grains IMR4198 for 1600 ft/s out of a 26 inch barrel. So, I loaded 7 rounds with 35 grains of H4198. Should be a hoot… 😉