This week I tried my hand at loading WC872 in the 45-70. My first load was 50/WC872 over 5/IMR3031 an a 450 gr. NEI GC WFN bullet. Accuracy was lousy. Next load was 60/WC872 over 5/IMR3031 and the Lyman Gould 330 grain HP. This time the accuracy was pretty good with 2" 100 yard groups. I don't know what the velocity was, but it was slow enough to hear the bullet slap the backstop, even through the hearing protectors. The others on the firing line keep looking to see what I was shooting. Sounded like a strong man hitting a piece of concreat with a big hammer. it really gets your attention. Cast soft enough to expand, this should be a heck of a deer load. Anybody want to guess about the velocity? BTW..These were both compressed loads. The 330 grain load was not too bad, but the 450 grain load, did tend to slap the shooter around. I would not want to plink cans with that load.

.......Checking the data I posted at Castpics generated in the MAS36 conversion's 24" bbl I got:

Straight WC872:

Lee PP'd 405gr & 67.0grs = 1287 fps
Lee PP'd 450gr & 73.0grs = 1365 fps (This bullet could be seated out further due to it's bore rider nose. 18" drop tube used.
Lee 500gr & 69.0grs = 1268 fps

Duplexed with 4.0/H4198 & 67.0/WC872 using the Lee 450gr slug gave 1523 fps.

Duplexed with 5.0/H4198 & 65.0.WC872 using the Lee 500gr slug gave 1470 fps.

I would call your 2" 5 shot 100 yard group a bit more than "pretty good", regardless of scope or iron sights :-)! I doubt any accuracy improvement would follow, but if you can recover bullets, you should try paper patching up some cast very soft. Patch the cast bullet, tumble lube and then run'em into your .458" size die.

Fire for effect into a sandbank or somesuch. Their appearance will be mind scroggeling to say the least.

........Buckshot

PS: The MAS36, 45-70 conversion:

Buckshot..I saw that data on castpics and wondered what kind of cases you use. My 60 grains load of WC872 over 5/3031 with the 330 Gould was about as much compression (about 1/2 of the bullet shank below the case mouth) as I cared to try. Yep, I used a very long drop tube. My cases are WRA 45-70.

I can extrapolate from your date that my 330/5 (3031)/60 (WC862) is probably in the 1,500 plus area for velocity. That is plenty for me and a 1-20 or WW+2%tin HP bullet will expand well at that MV.