Hello Dave,

The Sharps Rifle Co of Bridgeport Connecticut who built the original model 74 also used to provide PP bullets swaged to size and loaded PP ammunition. In all cases the alloy they used was a 20-1 lead/tin mix. They sold vast amounts of ammunition, if it didn't work they would have soon lost orders.

It seems to me that the company knew what they were doing. So use that alloy as a starting point, you should have no trouble with the bullets not bumping up. Do not use any unknown mixture especially one containing Antimony. There's no cheap way to get pure lead. Today, brass, powder and primers are not cheap and by shooting bullets of an unknown alloy provenance, your really wasting your money, so it costs a few cents more per bullet, so what? You'll only get good results if everything is consistent a variable content lead alloy bullet won't be. If you use pure lead and pure tin the mixture is repeatable time after time. Linotype and wheel weights are also not reliable, in their constituents.

Welcome to the wonderful world of PP bullets. 

My alloy has always been 1/25 No Antimony just lead/tin. Mostly premixed commercial supplied, sometimes I alloy it up myself.

Just put in a order for some pre-alloyed. Lead supplier gave me a good argument for changing and am going to give his advice a try.

He said optimal for smaller bullets is 1/20 reason is more tin helps fill out and gives better bullets. My 32/40 nose pour molds are cranky and better fill out would be an advantage. Most smaller bullets are used with Smokeless very little "bump up" and are over by about .002 to compensate. 1/20 is as soft as you need.   He also likes 1/30 for larger black powder bullets. Larger molds fill out is less an issue .40 calibers and up are mostly used with black powder, softer helps "bump up"

This advice from a expert when it comes to lead and casting, I thought it was worth listing too.  

Boats opinion, no good reason for adding Antimony to anything, it's used by the commercial casters who always tout "hard" cast. Hard is not good in our rifles it sells bullets that's why you see it. 2nd Harry on the lead, Bullet is the critical factor lead even pre-mix at 2 or 3 dollars a pound is cheap compared to the other cost of shooting.

Boats

Dave,
I did my first PP bullet shooting half a century ago, like everyone else I experimented, with loads, bullets, patching materials and lubrication. In the end I found out that the old timers knew what they were talking about. It's only in the last decade that I have read about people lubricating the paper patch. The patch is supposed to strip away from the bullet in the first few feet of flight once it exits the muzzle. Apply any form of lubrication to a PP Bullet's patch and you may well loose it's ability to shed the paper patch on exiting the muzzle of the rifle.

The best way to lubricate is by using a grease cookie sandwiched between two card discs beneath the bullet as the bullet travels down the barrel the rifling should cut the paper patch into strips which are removed by the air one the bullet exits the muzzle. If you have lubricated or glued the patch it may not separate at all, making that shot less accurate, especially at longer range. 

As for primers they can vary in results depending on the powder used. Large pistol primers are hot enough to ignite Black Powder with ease, but if your using one of the faux Black Powders you will have to experiment to find out what is best. At the present time you will be lucky to get your hands on any primers from what I have heard recently about US reloading supplies. 

Harry