I'm hoping some of the old-timers around herre might care to share their experience with various cast bullet designs.
I'm concocting a havy .458" bullet, ~550g, and I see a number that have only one or two big lube grooves on them, and often a bore rider nose.
Seems the benefit to having few grooves is more lube overall, by virtue of having fewer angles into the groove area.
Not quite sure why the bore rider feature is so popular (may be wrong about this anyway) but seems it could be to provide less resistance down the barrel, less leading, something else?
Sometimes, just for chambering in short throats, maybe that's all there is to it.
Now, I get that this whole cast bullet shooting thing is far from a science, and it's somewhat of a crapshoot as to which design will work in your gun, but maybe someone can help "shoo" me in the right direction here?
Many thanks.

I shoot a lot of BPCR matches and have used a lot of various heavy .45 cal bullets over the years.I think the reason why so many of the heavy .45 cal bullets designs are bore rider types is the fact that for most of the last 100 years these bullets were destined to be used in the 45-70 cartridge which is not the largest .45 caliber case to begin with.

Conserving powder capacity in the case and also the better bullet alignment in the bore are the reasons for bore rider noses.
Also a bullet is only a TRUE bore riding desing if the actual nose diameter of the cast bullet is within a thousandth or so under the diameter of the tops of the lands in the barel they are used in.Other wise(unless they are cast softer enough and pushed hard enough to obdurate or "bump up" at the nose when fired) they will not truly ride the bore...

I am curious,what .45 cartridge will you be loading these bullets in? Most currently available .45 cal bullet designs are just fine for use in the .45-70 as they are...

Friendly,
Can't help much.I've designed two moulds;one works fine,the other seems to be on Welfare.
I've shot some of those old Lyman bullets,and they were designed for more grease then is now needed.Advances in lubrication and barrelmaking have reduced the need for as much grease as before.
A bore riding bullet seems to align in the barrel easier.
Good luck,
Frank

Shoot more black powder and you'll appreciate those deep wide grooves. While I don't shoot black powder exclusivly, I do select bullet molds that carry an abundance of lube....no problem using less if the load requires it, but there is a problem if the load requires more and you don't have the space to put it.

Bore Rider does get the weight up front, out of the powder volume, and so long as the riding section is the right size for the bore, doesn't seem to harm a thing. But it does have to fit...slack here never does accuracy any good.

I sure agree with the need for adequate lube grooves for BP shooting, although I am still curious as to what .45 cartridge needs a 550 GRAIN slug when there a MANY good factory 500-525g molds out there??

Saeco makes three 500g+ .458 bullet molds in FP spitzer,RN and wide flat point respctively.Depending on how hard of an alloy they are cast in and what they are lubed with, they can be successfully used for everything from National level BPCR matches to hunting Cape buffalo in Africa!!

IMHO, the factories pretty much have .458" rifle bullet molds covered.....

Hi all -

jim62 -

Just to calm you down, he's designing ('cause he thinks it's fun) a 550 gr for me ('cause I want one) for my .45-70s.
May want a 600 gr next. :-)

regards,

I'm actually very interested in the idea myself.
Those old Sharp's rifles sent the 550's out at -what?- 1300 fps? Seems an easy task to beat that by a couple hunert at least.
And the further you get on the other side of 1600, the closer you get to energy levels of hot 405g loads, with a heluva lot better SD and BC. Should make a great rainbow rider for those looooong shots.

As for the 600g, you're going to be on your own there. That's approaching 1.4" of bullet. Might work great, might not, but if you look at the energy levels, it seems the 350-420g is right at the sweet spot, everything else above struggling to get the energy up. On paper, the 420-ish seems a good compromise in energy and SD. The 350 is about the SD equivelant of a 115g .264" or a 155g .308" or a 235g .375". To me, the 550g "feels" like the good heavy to me. Like SD of a 245g .308" or 370g .375"!!!
Guaranteed to stop a charging Squirrel.

And Jim62, as far as the factories having it covered, well may be true. I haven't seen many molds for over 500g. I have seen Saeco's 540g FPGC (what's a flat point, anyway?!) and there's a few things I'd change about it. The crimp groove is way off for the 45-70 as Marlin chambers it, at least, and I think you could get away with less lube groove, which equals less length, or more weight in same length. The nose job is pretty much what I have in mind, though.
Also, best price I've seen is $65. Dan at Mountain Molds will make it "my way" for less! ;-)

Maybe there is a good 550g design out there , with a .480" nose or so. I'd love to see it if anyone has a link.

Shoot straight!
Taylor

Try ballisti-cast, they are a class outfit. I have several of their moulds. They make a 540gr FNGC with the crimp groove at the correct place for the 45-70. It is a "Hammerhead" design with large meplat. The 45-70 throat in my Marlin lever was too short to chamber this bullet. I chose to run a throater into it to fit the round. It is very similar to the bullet used by Garrett.

Gents,

In the free world, "wanting" is as good a reason as "needing" when it comes to anything that goes bang,so have at it.

I have been shooting NRA BPCR silhouette mathes for six years now and have worked my way into Master class in the process.During those years shooting Sharps replicas in 45-70 with straight Black Powder from 200 to 1,000 + yards, I have noticed little difference in ballistic performance with bullets over 525 grains.That is why I brought up the mention of the factory slugs having things covered.

As to Flat Point bullets-all the Factory FP designs are 500g or less,so a custom maker would be that best route to get a 550g slug from...

Trouble with positioning the crimp groove so that the round chambers in Marlins is that it takes up significantly more space in the cartridge. I believe RCBS's 500 gr mould will chamber with no problems, the nose is the same size as their 400 gr. Check out http://www.mountainmoulds.com There's an online bullet design area that will show a picture of your new bullet. You can change a few measurements and look at it again. I have no relationship to him or his business, nor have I tried any of his moulds, but I do like playing with the design program.

Ryan

must be two versions of that bullet as the one i have runs fine through my marlin. The seaco version didint.Try ballisti-cast, they are a class outfit. I have several of their moulds. They make a 540gr FNGC with the crimp groove at the correct place for the 45-70. It is a "Hammerhead" design with large meplat. The 45-70 throat in my Marlin lever was too short to chamber this bullet. I chose to run a throater into it to fit the round. It is very similar to the bullet used by Garrett.

Ture...to have it cycle through the Marlin action, are going to have to add weight to the rear of the bullet and not the nose. Does take up case volume and limit the vel. that can be achieved.

From the looks of it, the RCBS 300, 425, and 507gr. bullets more-or-less share the same shape from the first driving band forward...to gain weight, more bands are addeed.

A big wide meplat does move more bullet weight to the nose, and by doing so it give a bit more case volume to play with. That big wide front flat does add to the terminal effect.

To gain a longer nose, could still seat the bullets deep enough to cyle the action, but that would limit powder volume even farther. Would also earn a longer jump for the first driving band to the rifling...that may not be imporatnat, some rifles can shrug it off and shoot well that way; most don't care for the extra distance.

IF dealing with a single shot (or other action that will allow a longer OAL) are several good long-nosed designs worth exporing...at least up to the limit of the barrel twist to spin them.