How hard is it leement a brass mold?

[Blkpwdrbuff]

I was looking at an MP Mold for a .41 Mag the 41 Hammer.
It is supposed to cast at .411. I would like it to be .413 for my Marlin 1894 FG rifle with the Marlin microgroove rifling.Has anyone done this before?
I haven't decided on a gas check or plain base Mold.
My alloy is 50/50 ww/pure +2% tin.
I would also use this in my Ruger Blackhawk.
Thanks in advance.
Blkpwdrbuff

[Recycled bullet]

Have you tried casting it out of lyman 2 alloy 90/5/5 lead/tin/antimony and then powder coating the bullet and pushing it through a bullet sizer?

[Blkpwdrbuff]

No, I have not bought the mold yet.
I also haven't gone over to the powder coating side either.
I'm just kicking this around to see if it's feasible, and something I may want to do.
I know guys have done this to aluminum molds, and wondered if it could be done to a brass one.
I have emailed Miha, about making it bigger, but not heard anything.
I believe he's busier than a one legged man in a butt kicking contest.

[JSnover]

I've lapped aluminum and steel molds, don't see any reason why brass would be a problem.

[Wayne Smith]

I'd suggest you contact Accurate and get a mold made to your specifications rather than trying to alter and MP mold.

[JonB_in_Glencoe]

I was looking at an MP Mold for a .41 Mag the 41 Hammer.
It is supposed to cast at .411. I would like it to be .413 for my Marlin 1894 FG rifle with the Marlin microgroove rifling.Has anyone done this before?
I haven't decided on a gas check or plain base Mold.
My alloy is 50/50 ww/pure +2% tin.
I would also use this in my Ruger Blackhawk.
Thanks in advance.
Blkpwdrbuff

Have you slugged your 41 mag?
Is it a Remlin?
I don't believe any of the Marlin 41 mag guns have the issues that the 44 or the 30-30 have...but I've never owned a Remlin.
My 1894s (1988 mfg) doesn't have any issues shooting a .411 boolit. Besides other molds, I have the Ranch Dog TLC411-255RF that casts smaller than 412...it's just a hair fatter than 411 and I size it to 411 when I put the GC on. Never had any lead fouling issues. I mention that one, because I load it hot. I also have the plain base version, but I don't hotrod that, never had issues with it.

[Blkpwdrbuff]

Wayne, I would but Tom doesn't make hollow point molds.
I know Erik hollow points molds, but if I could just get it all in one it would cost a bit less.
I would like to try and duplicate what Good Cheer did with his mold he had Erik hollow point for him and I would also like a 4 cavity mold which Miha does.

[Blkpwdrbuff]

JonB, I bought this Marlin 1894 FG in either 2003 or 2004 when they first came out. I don't know if this puts it into the Remlin Era or not.
I have not slugged the bore but I know it really really likes fat bullets.
I started out sizing at .4105 then went .411, .412, and finally .413. That was the sweet spot.
My Ruger Blackhawk likes the .413's also.
I had to have the chambers reamed out. The largest one was .410 and the smallest was .406. Got them reamed to .412.
I guess this just shows us guns can be as individual as people.

[JonB_in_Glencoe]

Blkpwdrbuff,
You are correct, "guns can be as individual as people"
I just made my post in case you were just guessing about your Marlin...you obviously already know.
also, Remington bought Marlin in Dec 2007.

[Minerat]

I have 2 MP 41 moulds, a 413640 and a 413265 the 640 drops at 0.416 & the 265 at 0.414 with my alloy. Both have gas check bases too. The 265 was a group buy called a Trueshot clone. I size back to 0.410 for my SBH and Henry and they shoot just fine.

My thought is that you won't have to leement the mould as all of my MP moulds (10) cast a little over size. My alloy is not a scientific mix I use wheel weight lead with a little tin and a small lyman bar of lino once in a while in a 10# pot. Pencile test says the BHN is around 12.

[kungfustyle]

If you powder coat the bullets, the process should increase the diameter by .02. Maybe worth a try.

[longbow]

There is also Beagling the mould. That can increase diameter by up to about 0.003" and no permanent change to the mould. That would be the easiest thing to try if you need a larger diameter. If it doesn't work then lapping should do the job but you have to go slowly.

As per JSnover's post above, I have also lapped iron and aluminum moulds and I don't see any reason a brass mould can't be lapped. Brass will be softer than iron/steel but harder than aluminum. I would use a fine valve lapping compound and make a hand lapping slug... as in don't run a screw into the lapping slug then use an electric drill to spin it! Cast your lapping slugs throughn a hex nut or drill them and install a screw but turn the lapping slug by hand.

First I'd try Beagling. It may well give you what you want in diameter with virtually no work and no permanent change to the mould.

If Beagling doesn't work I would also be inclined to try powder coating before lapping a Mihec mould! I would worry about messing up such a work of art!

Longbow