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View Full Version : custom mold made for 30 caliber, lube grooves with J&M???



rszkutak
02-21-2014, 03:17 PM
We'll I'm sure this is going to open a huge can of worms... SO here it goes.

I'm going to have a custom mold made, it seems what I want no one makes so I have to go 100% custom made for what I want.

I'm looking to do a 30 caliber spitzer mold, 175 grains with gas check. I am using the J&M coating so it negates the need for using traditional lube on boolits. And now that brings me to the point of my post.

Since lube grooves are used for lube (duh), which I am not going to be using any traditional type of lube will I see any issues with having the boolit mold made for me without any lube grooves but of course still having the obligatory gas check groove?

I am trying to preserve the BC of the boolit by keeping anything to create drag and turbulence down and to a minimum, since the lube grooves aren't needed, why do I need to have them in the boolit in the first place???

Thoughts???

Love Life
02-21-2014, 03:23 PM
I think it will be a great experiment. You will have increased bearing surface and I have been considering having some grooveless boolits made as well.

rszkutak
02-21-2014, 03:24 PM
It's a couple hundred buck experiment too... UGH!

Beagle333
02-21-2014, 03:26 PM
I always wondered, especially with a spitzer boolit, when it gets swaged into the rifling, with no grooves to fill, where is that extra lead gonna go? Will it deform the nose or maybe squeeze back to the base? :coffeecom

rszkutak
02-21-2014, 03:28 PM
I always wondered, especially with a spitzer boolit, when it gets swaged into the rifling, with no grooves to fill, where is that extra lead gonna go? Will it deform the nose or maybe squeeze back to the base? :coffeecom

I agree, however I would think that the same thing applies as it does in FMJ boolits. I dont think it would deform the nose, more than likely we would have an impact to the base of the boolit.

Love Life
02-21-2014, 03:30 PM
It'll probably do what a jacketed bullet does. Well, at least in my mind.

I read an article years ago about squeeze bore rifles, and I wonder if squeezing it down from .001-.002 will do. Kind of makes me think of an obermeyer barrel.

Wolfer
02-21-2014, 06:48 PM
Since we are talking experiment here. Could you take a cheap lee mold and cut the lube grooves out. If it didn't work your not out much.
You could probably sell the lube grooves to waksupi for part of the cost of the mold.:roll:

runfiverun
02-21-2014, 08:41 PM
you could drill out a mold and make it slick sided.
I done this to a 180 gr sp type mold and made it able to take copper tubing.
I cut the tubing and press the ends over then pour the alloy through the heated tubing.
the pressed over ends locks the lead at the front and protects the base.
simple matter pushing it to 23-2400 fps and that 1/2" long exposed nose mushrooms like a partition.
even with the small point.
to get there I drilled a little small then lapped the mold to size using the tubing as my lap.

anyway the same could be easily done to a regular mold, as a prelim experiment before dropping the bucks on a custom mold.

longbow
02-21-2014, 09:06 PM
If you have access to a lathe you can easily make a cylindrical push out mould like the old ideal Cylindrical moulds for paper patched boolits. They are simple and work quite well.

I have made them for paper patched boolits for .30 cal and .44 cal and I have made the same style of moulds but at typical 0.001" to 0.002" over groove diameter for .30 cal, .303 cal, .44 cal. 20 ga. slug, 12 ga. slug. Some are shot as cast with a lube cookie under and some are cast slightly small then knurled to final size.

Hmmm, rereading, you want a ga check. Well, a PB gas check would work on one of these but I guess otherwise you are right, you will need a custom mould. You could get Accurate to bore a cavity with gas check shank then get Erik (HollowPoint Molds) to make a nose form/pin. The mould would only cost $99.00 for an aluminum 2 cavity then the cost of having the nose form made which wouldn't be a lot.

Just a thought.

Longbow

rszkutak
02-21-2014, 09:27 PM
You've both brought up great points here. My issue is that I don't cast by "hand" like most people do where as I use a Magma Master caster so I need to have iron molds otherwise I will tear the hell out of the AL blocks.

Yes I will of course be using a GC on this boolit, I have plenty of those laying around in 30 caliber. My lead comes out about 22 BHN so i'm not really worried about it being too soft.

runfiverun
02-21-2014, 11:27 PM
to keep the gas check you'd need to make a cutter instead of using a drill bit.
the cutter would be a simple L shape and about the size of a drive band.
you'd have to start it in the drive band area and move it through the lube groove.
a gentle slow speed should do the trick
in fact the 30-165 bevel base 30 cal mold magma makes would be about perfect for this as their nose comes out at 298 to begin with and should take the p-coat without being too big.
oh that bevel base it has will take a gas check too.

DLCTEX
02-22-2014, 08:13 AM
I would not start with a mould for the Master Caster but rather a single cavity to prove the concept before spending the bucks for the more expensive mould. If you later decided the concept needed grooves (as in Barnes copper bullets), a different give or nose, or any number of changes, you will save bucks getting what you want.