I assume the HB bullets are grease groove? If so I wouldn't put any lube in the hollow base. It wont do much following a bullet with lube, except to make a mess in the bore.

J.G.Terry wrote on Mar 3^rd, 2018 at 2:03pm:


Why? What's wrong with a hollow base bullet in a modern bore? I use them a lot, with great results.

I've got a Lee #459-405-HB mold I bought to play with in one of my .45-70's and it casts a very nice bullet. Of course it has the same issues most aluminum molds have in occasionally galling the mold top, so I have to keep the top smooth and coated with graphite from my lead pencil. But it does cast great bullets, and seems to do so as easily as any non HB molds do.
It also works very well in bores from .457" or even up to .462".

I have two 58 caliber HB molds. Ones a Lyman Origional style Minne 585 grains removable base pin, others a Lee “Trash Can” the Lee is easier to use and cast a better bullet.  It’s hard to maintain heat in the Lyman’s pin, reject rate is higher.  The Lees attached base holds heat better. I put up with the Lyman because the bullets look right and are better long range Minnes.

One comment avoid wheel weights, all the old articles and manuals recommended WW. Written when car wheels were steel and weights were lead/tin. Today wheels are Alloy and weights are made of who knows what. 

Bullet is the most important thing to your results and good clean lead/mix is the critical success factor. Go to RotoMetals web site and order some 1/30 for your 45/70

PS Trash Can refers to the bullets shape. 

Boats

Hollow bullets in Modern rifle. This is basic. The skirt on a soft hollow base bullet will split or blow. The Lee 405 bullet is designed specifically for oversized TD barrels . This would be at TC pressures. Mine were cast from unalloyed lead and hand lubed with SPG. Go ahead and give it a try with hard cast bullets in a modern rifle.  Report back how it works. 

JGT, I've used HB bullets in pure lead, 1:30, and 1:20 mixes, and in my old original barrels, and newly rebarreled guns too. Never had an issue with bases splitting, and can't see how they could. The few slugs I've looked at when checking expansion into phone books showed no signs of bases splitting. I have no idea what you're talking about, and don't know what "TC" pressures are? Is this something to do with Thompson Contenders? And what kind of pressures are this extreme?

Thanks for all the feed back. Terry, "''' a heavy charge of smokeless?"''', in a trapdoor? That WOULD be a disaster!!! As stated in my original post I will be using black powder ONLY and it is damn near impossible to get more than 70 grains of BP in a 45/70 case.  I am not worried about too much pressure blowing the skirt. I have already cast the bullets and they came out pretty good both in pure lead and ww material,, by the way Guys I worked in the trucking industry for 25 years and these ww's are the old clip on type from those big steel truck wheels,, no zinc in the mix,,,......Ed

P.S Marlin Guy, did you use a thin card over your powder or will that stop the expansion?