Tapered Bullets? What to do with them?

[lar45]

A friend sent me a 50 cal mold to try in my Swede 12.7x44r Rolling block.

It's a LBT 508 475 HH. The lube grooves are angled, my thought is they look like scrapers for cleaning out BP fouling, but the lube grooves are not very deep so they won't hold much lube.
The second odd thing is the bullets are tapered going from .508" at the base to .496" at the top driving band.
I cast a small pile from 50-50 WW-PB. I'm going to pan lube with new BAC and load in cut down 50 AK brass to try them.
Any thoughts on what this mold was meant for?

[Winger Ed.]

Shoot 'em and see how they work.
Whoever designed and produced the mold might know what they were doing.

[243winxb]

Not a muzzle loader. Taper is in wrong direction. BP bullet loaded from chamber?

Would seem to be designed as a "bore rider" ? My guess?

https://en.m.wikipedia.org/wiki/.500_Nitro_Express

[Shanghai Jack]

Taper bullets brings to mind breach seating.

[Alstep]

I have the same rifle and always wanted to load for it, so will be watching this thread. What do you form your brass from?

[lar45]

I make my brass from 50 Alaskan cases cut down to 1.750" I gather there may be didderenr chamber lengths, so be sure to measure yours.
I use a 500S&W sizer die to size the top of the case to hold the bullets.
The bore on mine is .475" and groove is .505"
The originals were loaded with a hollow base .502" bullet. Some people say they load .510" bullets, but they won't chamber in mine.i did Beagle the Lee 500-440 and they shot pretty good. I've been loading IMR4198 to around 1250-1350fps.

[lar45]

https://castboolits.gunloads.com/sho...-Rolling-Block

Here's a link to some load data.

[megasupermagnum]

I have a hunch that it was meant to be paper patched, and loaded in a 50-70.

[Taterhead]

I bet if you emailed Veral Smith at

LBTisAccuracy@gmail.com

he'd be happy to explain the design logic.

Beautiful mold!

[JSnover]

Who made the mold? Could be someone's experiment with bore-riding or breech-seating boolits.
BACO (among others) offers some molds with driving bands cut to larger diameters from nose to base, they're just not as 'extreme' as that one.

[lar45]

It's a LBT mold

[Gobeyond]

It says to me the small end would fit the lands and the trailing band goes in the grooves.
But you right the is some specific purpose for a tapered bullet. Sometimes they pp them. But the bullet masters, etc, would know.

[lar45]

Sent an email off to LBT...
Shot 10 of them tonight, pan lubed with new BAC, barrel was spotless. Was very hot and humid. Pushed a few flyers until I settled down. Looks like it wanted to shoot, but...
I'll have to try again on a better day.

[DonHowe]

Tapered bullets are often used for breechseating as the taper allows the bullet to be fully engaged in rifling without as much engraving/dustorting as with a cylindrical bullet. This is like the Pope style bullet such as the one I use in my .32-40 High Wall. But the taper is also like Loverin-designed 311467 which is loaded into cartridges in the normal manner. In this case the taper of the bullet allows it to be seated touching the rifling but without engraving into the rifling. As the tapered bullet enters the barrel the entire bullet length except for a fairly short nose (as in a Loverin bullet) where a bore-ride bullet typically hase a long nose with short body/engraving length. Given proper fitting, both types work.

Back to my .32-40, barrrl dimensions are .314 land and .321 groove the tapered bullet I shoot tapers from .314 on the top band to .323 at the base. When seated into the throat so the base is ~1/16" ahead of the chambered case the forward band is bore-riding with the rest of the bullet gradually engaging the lands until about half the length of the base band is engraved. The gas-checked Loverin-design 311467 will begin to do exactly the same thing if seated out of the case far enough though extracting a live round loaded thi long will likely leave the bullet stuck in the case.

Hope this helps some.

[lar45]

Makes lots of sense, thanks much.

[Green Frog]

Tapered bullets are often used for breechseating as the taper allows the bullet to be fully engaged in rifling without as much engraving/dustorting as with a cylindrical bullet. This is like the Pope style bullet such as the one I use in my .32-40 High Wall. But the taper is also like Loverin-designed 311467 which is loaded into cartridges in the normal manner. In this case the taper of the bullet allows it to be seated touching the rifling but without engraving into the rifling. As the tapered bullet enters the barrel the entire bullet length except for a fairly short nose (as in a Loverin bullet) where a bore-ride bullet typically hase a long nose with short body/engraving length. Given proper fitting, both types work.

Back to my .32-40, barrrl dimensions are .314 land and .321 groove the tapered bullet I shoot tapers from .314 on the top band to .323 at the base. When seated into the throat so the base is ~1/16" ahead of the chambered case the forward band is bore-riding with the rest of the bullet gradually engaging the lands until about half the length of the base band is engraved. The gas-checked Loverin-design 311467 will begin to do exactly the same thing if seated out of the case far enough though extracting a live round loaded thi long will likely leave the bullet stuck in the case.

Hope this helps some.

^^^ This! ^^^ Thanks, Don, you saved me from having to type just about word for word what you said!
Best regards,
Charlie the Frog

[DonHowe]

Having an idea of Veral's thinking, if I had any money, I would bet this mold was designed for a specific firearm and use and diameters determin# by a slug of the throat of that particular rifle. I am wondering if he may have made this mold for a personal friend as I don't recall ever having seen this scraper-like bsnd configuration on any of his cataloged molds.
I am also pretty sure someone will educate me about this!

The bavk end of a tapered bullet can be sized conventionally for loading in cases. Also, considering the stated bore/groove diameters of the rifle in question I think I might try casting the bullet of a soft alloy and let the powder to make the front end fit closer.