Can you size-up a .356" cast boolit to .365"?

[Robanada]

I've got a makarov and I'm looking at these 95gr lee molds that look very tempting, but the problem is that they're nowhere to be found, and where they are found, they're seriously marked up.

There seems to be a lot more supply of the 9mm luger molds, and so they're not so expensive right now. Plus, I can only find a 2 cavity makarov mold and I can find 6 cavity luger molds. I've found several 102 gr luger molds, which shouldn't be too much heavier than the 95 gr mak molds (I've seen commercial mak ammo as heavy as 115 gr). I was wondering if, once I slug my barrel, can I expand a cast boolit from .356" to .365"? Or is that too much of a size difference?

[Tatume]

Dear Rob,

Yes, you can do it. However, I suggest that the utility of a six-cavity mold will be lost. To "bump up" a bullet you will need to squeeze each one in a vice. When the bullet is compressed from front to rear the diameter will increase. You will then need to size the bullet to your desired diameter in a lubrisizer. This is a time-consuming process that is usually only undertaken for the purpose of feeding an exotic firearm for which bullets are not otherwise available. Results are frequently not the best, but are better than having no bullets to shoot. You will probably be better off to wait out the feeding frenzy and purchase the correct mold.

Take care, Tom

[Maximumbob54]

I think the term is "beagle" when you cast a bullet, drill a hole in the base, get a screw nice and tight in the hole, add some jeweler's rouge or something similar (I think I've read even Comet will work) and using a power drill with a bit slowly work the bullet in each chamber. I would do this is small short runs and then cast to see what your labor has created until you get it where you want it.

[Tatume]

Hi Bob,

He didn't ask about modifying the mold, he asked "can I expand a cast boolit from .356" to .365"? However, yours is a good suggestion. What you described is lapping the mold to a larger diameter. To "beagle" the mold is to add a shim between the closed halves. The result is a slightly oblong bullet that can (usually) be restored to concentricity in the sizing die. It might be worth a try, but I still believe it would be better to wait and get a correct mold.

Take care, Tom

[HATCH]

Mihec made a hp mold for 9x18
at the time it was only 2c but it might be made in 4c now.
Great mold. Cast perfect boolits everytime.
The makarov is snappy to shoot. Good luck on recovering all your brass. I always loose 10%.

[longbow]

Maximumbob54:

What you are describing is lapping a mould. I have lapped several moulds successfully but lapping is usually limited to about 0.003" max. cavity enlargement.

You also need a reasonably coarse valve lapping compound or similar to remove that much metal then finer to finish and it takes casting several laps during this process. Also as cavity size is increased generally some out-of-roundness starts to occur and is almost unavoidable, along with rounding of all internal edges.

So, in my experience, while it may be possible to lap a mould 0.009" it is not likely practical and the results would very likely be poor.

Beagling is also limited to about 0.003" before finning starts at the mould splits.

A combination of Beagling and lapping might get 0.006" but not likely good quality boolits.

As Tatume says, some people "bump" boolit sizes up a bit and that can be done in a sizer/luber though again, 0.009" is a lot. Tatume's suggestion of squeezing in a vice or possibly impact should work but again, 0.009" is a lot then the boolits would have to be sized back.

None of that really helps the OP but I thought I would clarify things a bit on what is and isn't likely to work.

Longbow

[runfiverun]

you ain't gonna lap a mold that big.
you ain't gonna beagle a mold that big.
you could swage a boolit that big but the swage die will cost you more than 3 molds.
rcbs makes a nice Makarov mold.
yeah it is a 2 cavity mold but i'd bet 300 boolits an hour is enough to last you a while.
spend a Saturday casting and a sunday lubing and you should be covered for most of a year.

[MtGun44]

Going to be a stretch, might bump up or something but basically
you can lap or beagle (NOT the same thing) maybe .003 or .005
without problems after that you are pushing it. Not saying it is
impossible, but impractical is close.

Paraphrasing Roy Schieder in 'Jaws' - "You're going to need a bigger mold."

Bill

[Robanada]

Thanks for all of the input guys. I guess I'll have to just wait for that mold to become available =\

I don't know 100% how bullet sizing goes, but I thought that there was a top punch that pushed it into a sizing die? Mechanically, isn't that the same as putting it in a vicegrip and squeezing it down?

[MtGun44]

Theoretically, yes, but the alloys we use are way too hard for the lubrisizers,
which are not nearly strong enough, either. There are swaging systems to make
boolits/bullets, but a lubrisizer isn't it.

You size DOWN, not UP.

Bill

[Boolseye]

There's a group buy happening for an MP Mak mold. Go for it.

[GaryN]

If I couldn't find a mold big enough and there wasn't a group buy that had one big enough and I had to have it now, I would get the six cavity and send it to Eric. He can open up the cavities to what you want.

http://www.hollowpointmold.com/

Or you could have accurate molds make you a custom one which would be excellent quality and a fair price.

http://www.accuratemolds.com/bullet_detail.php?bullet=31-150B-D.png

[Maximumbob54]

Ranch Dog had a really good looking Mak mold. My chumpy Mak wouldn't shoot them though. I handed a few to another guy at the range that happened to have a pretty nice (as far as Mak's go) Bulgy Mak and his shot that same ammo great with no leading.

[gefiltephish]

If funding is not a problem, try this page and scroll down to 35-###. Also look at the 36's if you don't see a design to your liking. Or you can ask Tom to clone whatever bullet you want. You can get up to 5 cav.
http://www.accuratemolds.com/catalog.php?page=3