Hollow Base .45 cal Boolits

[Sliver Shooter]

I have several LEE molds, for my 45-70 , that have the hollow base. The cavity isn't as hollow as the old minnie ball. I'm wondering about if these will swell to catch the rifling upon ignition? They are sized to fit pretty snug to the bore. I want to try them in my muzzleloader and in that they are very snug as well. I would cast them from soft lead .

[BLAHUT]

I would venture a guess; if cast in pure lead; YES; keeping velocities at about 1200 FPS or so; with lure lead; all I use......... mine shoot very accurate....

[Gobeyond]

I read an article about that. If some hollow base walls are to thick to obturate. He seemed to think they were.

[Sliver Shooter]

I would imagine using soft lead, and loaded much more than 1200 fps, there would be leading. Adding some hard to lessen leading to the mix, could cause the base not to bump. Shooting a 450 gr. hollow base at 1200 fps would have quite a bit of energy remaining at 100yds, I would think. That's a big chunk of lead. I know todays muzzleloaders can shoot far beyond 100yds but I also know you can close that distance on a deer. I also have a LEE 500 gr. with a flat base. That one with a lubed felt under it, I have seen, grouped well at about 1000fps. There again cast of soft lead.

[45workhorse]

Ought to make a nice 50 cent piece of lead after smacking a steel target!

[Kosh75287]

I guess there is a thin margin between "soft enough to obturate" and "hard enough to prevent severe leading". Anyway, isn't this what all the 40:1, 30:1, and 20:1 lead:tin alloys were supposed to address?

[Gobeyond]

Yes, add tin and a good lube.

[Larry Gibson]

The Lee 405HB bullet is a replica of the M1873 45-70 bullet. However, the term "hollow base" is a misnomer in that it was never intended to perform as does the HB of a Minie' style bullet. The hollow in the bottom of the bullet is actually referred to as a "dish" which is intended to keep the weight at 405 gr while maintaining the specified external dimensions. It was found the 405 gr M1873 or the Lee bullet does not have the mass to obturate sufficiently for best accuracy with BP level pressure loads. This was why the 45-70 bullet of 500 gr was developed in 1872 as it had the mass to properly obturate. Back then they used .459 sized bullets in the service rifles which had .460+ grove diameters.

If loading a bullet that is at or over groove diameter a true Minie' style HB bullet serves no real purpose. As to the thick skirt on the Lee 405 HP it, like the original bullet it replicates, gives little, if any, expansion/obturation at BP pressure levels. A true Minie' style HB, however, can obturate and can give too much expansion/obturation with a too soft alloy at top end BP load levels in the 45-70 with the bullet skirt being "blown" on exit from the muzzle.

[45workhorse]

I like seeing skirts blowing in the wind!

Just not my minie skirt!:bigsmyl2:

[Good Cheer]

I have several LEE molds, for my 45-70 , that have the hollow base. The cavity isn't as hollow as the old minnie ball. I'm wondering about if these will swell to catch the rifling upon ignition? They are sized to fit pretty snug to the bore. I want to try them in my muzzleloader and in that they are very snug as well. I would cast them from soft lead .

Hey there Sliver Shooter.
Shooting .457 boolits in a .458 bore / .470 groove muzzleloader with 24" twist, the various off the shelf Lyman 45-70 molds expand to fill the grooves just fine. Over powder card wads are a good thing.
To inhibit blow-by gas cutting on gas check type stepped bases more and more card wads are a good thing.:rolleyes:

[Nobade]

I was using that exact Lee 1873 bullet yesterday in my P-H Volunteer. At 70 grains of powder, they did not seal. At 80 they did fairly well and at 90 grains they were super accurate and definitely going supersonic. Cast from pure lead, lubed with Bullshop NASA lube, and run through a .450" push through die to fit the .451" bore. They slide down by the weight of the ramrod. So yes, it does work.