Odd WC design

[NoZombies]

I've got an old Modern Bond Wadcutter mold for the 38. I've had it for quite a while, and when I got it, I recall thinking that it looked as though the bottom driving band looked like it tapered to a smaller base diameter. Time goes on, and I hadn't cast anything in quite a while, and then the other day, I had the chance to cast again, and decided to try out the old MB mold.

After casting up a few of the bullets, I've got to say, the mold casts very nicely. But I've also got to say, I was right about thinking the base was tapered. I can only assume the base was tapered in such a way in order to deal with thickening brass?

The mold drops at .360 from my alloy, but then the base of the bullet tapers to .350. the base driving band is very wide, and there is a crimp grove and slight full diameter protrusion on the front end of the bullet. The design is the J358 710.

Has anyone cast with this one before? Have any insight to the purpose of the taper if I'm wrong? Am I right?

I didn't take any photos of the bullets I cast, so I'll have to do that later. In looking, I see that the "standard" length for the J358 is 610, rather than the 710 on my mold. It would also seem that the taper occurs on the portion that makes it longer than normal.

Any thoughts?

Here's the J358 610 from the Modern Bond Catalog:

[stubshaft]

Maybe some kind of quiet or gallery boolit?

[Ben]

The mold drops at .360 from my alloy, but then the base of the bullet tapers to .350.


What happens to the bullet ( and accuracy ) when the .350" base enters the barrel and gases are traveling around the bullet base ? ?

[runfiverun]

might have been modified to take a gas check.
the inside of a gator check is @349.
a thinner ideal slip on might be about right..
i have put checks on tapered bases before.

38 cases do taper on the inside.
win and fed used to make straight sided cases for thier target wad cutter ammo.
that's why it was so accurate. [and hard for a reloader to duplicate]

[Mk42gunner]

I would say you are right about the base band being tapered to fit a standard case, but like Ben; I wonder how it will shoot.

Those lube grooves look huge, I bet it will be over lubed even with only one groove filled.

Robert

[starreloader]

I have an old Modern Bond 38 cal 160 GR. RN, B-358-742.. It has the same slight taper to the base of the bullet base.. ( not what you would call a bevel-base style that is common today ) A friend also has a wadcutter mold that has the same style taper to the base of the bullet... My mould cast a very boolits!!

[mooman76]

Kinda looks like a BP mould with those extra large lube grooves.

[Texas Tinker]

That cross section looks very simular to a couple of REAL (Rifling Etched at Loading) molds that I have for muzzle loaders.
One is a 200gr. pointed design in .45 cal (.457 as cast pure lead). The other is a 300 Flat point that I have never used.
Your .360 diameter should be right on the money for a .36 cal muzzle loader

[NoZombies]

I'm curious to try the design as well. I'm not sure how the tapered base will do, never can tell with these things until you try. I do suspect it would be overlubed even with just one groove lubed, but with the extra wide base band, maybe it would be okay.

As for the design being for a BP rifle; I'm pretty sure the catalog note about it being for the .38 special is accurate. I suppose BP WC loads in the .38 special could be interesting, and a good use for that lube capacity...

[StrawHat]

...As for the design being for a BP rifle; I'm pretty sure the catalog note about it being for the .38 special is accurate...

They only made the mold, why would they know anything about it?

[NoZombies]

Well, after getting back to my mold, I have to make a correction; the mold is marked "J358 610" after all, but the base sure doesn't look like the one in the catalog illustration. You can kind of see the taper in this photo:

[nanuk]

I'm an idiot....

[Dale53]

The ad reads plainly, ".38 S&W Special"...

I am betting that it will shoot well. Keep the bullet metal relatively soft (1-20 tin/lead or WW's+50% scrap lead+2% tin) and size to .358" and it'll shoot well.

If the lube groove holds too much lube (just lube one groove) then you can always use "shake and bake" (either Lee's liquid Alox or Recluse's formula).

FWIW
Dale53

[nanuk]

The ad reads plainly, ".38 S&W Special"...

Dale53

Bwahahahaaaa....

I learn something new every day

I never have paid that much attention, but I can't remember when the 38Special was actually properly refered to as the 38 S&W Special!

I always thought the S&W an the SP were two separate cartridges....

now I know there is two versions that share the S&W nomenclature.

Thanks for bringing that up Dale53.

[Longwood]

The reason for the taper is because of how deep they get seated into the case.

[scrapcan]

Just a mention on the MB moulds. They are marked with diameter and bullet length.

And when you load it make sure you use brass of the same length, it will help with the crimp groove and seating. I think this is the MB way of not having to have a cannelure at the base of bullet for the target loads.