View Full Version : Modifying Lee molds to plain base

June 7, 2010, 12:15 PM
I have a Lyman 4500 lubrisizer, and it worked great with some plain base bullets that I bought, but all my bullet molds (Lee) have bevel bases and I just can't get the thing adjusted right. A little lube on the bottoms would be irritating but I could live with it. The lube gets under the bullet and pushes it out of the sizing die when I raise the handle! I end up with lube everywhere except in the grease grooves. So I've been using Lee Liquid Alox on all my bullets and the Lyman collects dust.

Has anybody drilled or ground the bevel out of a lee mold to make a plain based bullet? (I should probably try it with a 2-hole mold before butchering a 6-holer.) It's probably the same as converting a gas-check mold to plain-base, but with less metal to remove. Would it be best to clamp the mold shut and drill it out on a drill press, or grind it out by hand with a Dremel tool? Or maybe I can find an end mill the right diameter and twist it by hand with a tap wrench...

June 7, 2010, 12:32 PM
Sketchy work there, If I were you I would put it in a vise to keep it shut and sturdy.

Then I would find a really good drill bit the same size as your bullet mold. Drill it, be careful and make sure the bit shaves it off bit by bit rather than "Biting" into the mold.

The drill press is a good idea but how can you keep the mold in one spot?

Make the fine adjustments with a dremel until you get the desired result.

Take your time, starting with a 2 cavity sounds like a good idea. I have no experience in modifying molds but if I were to drill into my aluminum molds, this would be the plan.

June 8, 2010, 08:20 PM
The bevel I removed by gettin my 3X lookin glass (with lite) & a exacto knife !

Ya can remove the mold if ya want but i did`nt & it turned out purty good , if ya go a little larger so what, the sizer will take care of it .

I took rubber bands to hold it together so I could turn it any angel in my hand .

If ya use a drill go smaller then use the exacto .

Have`nt tried a GC - - - -yet:cool:

Dang forgot to comment on the lube problem , pressure control !!
I find if I try to put enuff pressure to lube a few this is what happens but if I "bump" the handle for each bullet problem lessens , this is the technique you must use on soft lubes !!

Another aspect is adjustment sometimes adjustin the bullet up or down a half a turn will solve problems , I start with the bullet hi & adjust down until I get the desired affect with minimum pressure .

June 8, 2010, 11:33 PM
The H&I sizing dies have small holes in them that can be plugged with shot. May take some experimentation on your part but it does work. Just remember if you remove the bevel you will have to bell the case mouth. Also there are people who can make you a custom sizing die; so that is another option.

June 19, 2010, 08:32 AM
For those of you who are not aware, they make mill vices that will actually bolt to the slots on the drill table. a good mill vice will adjust for tilt, forward and back, and side to side.

June 19, 2010, 04:26 PM
Yeah, but. . .

Lee is the only manufacturer other than LBT that I am aware of the lathe-turns the mold cavities. It is the exceptional roundness that results that allows these bullets often to beat conventional cherry cut molds for accuracy. Not that cherry cutting can't be done well, too. It is just technically more difficult to maintain exact center and keep chips perfectly cleaned out as the block halves come together. A not uncommon issue with cherry cut molds is bullets that are bigger on the flashing diameter because chips kept the halves from coming together perfectly at the end of the cut. That's not a problem with Lee or LBT.

You want to do a perfect job of removing the base bevel without your bullets winding up out of balance. Also, you want the final bullet dimensions to seal against the sizing. Any way you look at it, it is going to be more expensive to tool up to do this accurately than it is to pay Lee a custom fee to cut new molds without the bevel base for you.

The best approach is to use a milling machine or a lathe, but it can be done on a drill press. You want an X-Y vise or an X-Y table to hold the vice on the drill press platform. You need a center finder to know when you've got the mold cavity axis perfectly coaxial with the spindle of the drill. Otherwise, material will be removed off-center. Drilling soft material without grabbing requires a sharper drill point angle than standard drills have. Also, you want no chatter, so a single flute drill with about a 90° tip angle is best if you are going to drill? A variable radius boring bar chuck instead of a drill will let you turn off a few thousandths at a time until you clean the bevel to the full diameter of the bullet. That is the approach that is least like to introduce an error, but then you need to invest in that special chuck.

You may also get away with stepping up through chucking reamer sizes to final diameter, but I'd only do that if I had the reamers already. And you still need a center finder to get the mold cavity axis coaxial with the drill spindle.

Just fixing the lube error. . .

I can think of other ways to deal with the lube issue. One thing that is likely to help is to buy an RCBS lubricating and sizing die. The RCBS and Lyman dies both fit each other's lubri-sizers. The difference is that the Lyman dies have a vertical string of lube holes on the side, while the RCBS has just one entry hole level.

In the Lyman die, lube hits the bullet at as many holes as line up with the grease reservoir. The RCBS dies are made with a single ground groove like a bullet lube groove on the outside of the die, and the lube flow holes are drilled into that single groove. The outer surface is recessed slightly so the lube can find its way from the reservoir to those holes. That is why lube entry is just at that one level in the die. If you set your bullet up to align the bottom edge of its lube groove with the bottom edge of the RCBS die holes, that's where it will flow in. After filling the bullet lube groove, you have no lube pressure yet at the bevel, so you can raise the handle and push the bullet up past the lube holes before the bevel can fill. The ejector ram has only to rise one hole diameter to block the holes and cut off lube flow. By the time the bullet exits the top, a good length of ejector ram is in the way of the lube flow.

Another thought is to stop using the lubing function of the lubri-sizer at all. Just dip the bullet in mineral spirits as a temporary lube, and run them in and out to size them. After the mineral spirits dry off, use Lee Liquid Alox or White Label Xlox to coat them and let it dry. Works fine with as-cast bullets that will be sized by the gun barrel as well.


July 20, 2010, 09:11 PM
I had this problem for years and never could get the problem solved on my machine. Lyman or RCBs size dies both did it. If I didn't have much pressure to start with and gave the ratchet a twist to fill the grease groove, then when I raised the ram, the bullet would still come shooting out. I figured that thousands of others may have solved the problem, but I couldn't and didn't want to spend any more time working on it. The idea of spending a bunch of extra money for special bevel base plugs seemed like a waste of money.
I wouldn't buy a BB bullet mold even today.
I also found that not sizing and just lubing worked much better for me in 9mm, .38, .44, and .45 (accuracy went up and leading went down). After that, I just put the lubrisizer away (would someone like to buy it and all the plugs and dies?) and pan or tumble lubed. For awhile, I even sat around packing the grease grooves by hand.
YMMV, but what is gained with the BB? Seems like the solution to a non-existent problem that just created more problems.
Always thought that there might be some advantage for the commercial casters and their Star Lubricators.
Next, Lee is very cooperative. Has anyone talked to them about cost for them to mill off the BB?
Also, for others out there--has anyone seen a benefit with the Lee tumble-lube mini-groove molds? I found them harder to cast "perfect" bullets and the standard molds work just as well with LLA--and there might even be some miniscule reduction in pressure with an empty grease groove compared to one that is full.
Also, it seems a shame that 99.9+% of the lube never contacts the barrel anyway and if half the lube leaves the band after leaving the muzzle, it might upset accuracy.

February 4, 2011, 12:16 PM
I have done this on one occasion. I had a single cavity mold for the .375 Winchester that I wanted to turn into a flat base. I chucked it up in a 4-jaw chuck in a lathe and centered it using a dial indicator, then gently turned out the bevel base. It worked very well, and seemed to shoot better. It certainly lubed better. I traded the gun and the mold, etc shortly thereafter, though, and now am a 45-70 shooter.
I imagine a two or six cavity could be done just as easily, as long as you indicate each cavity in properly.

Here's a couple of pictures of bullets cast before and after.



February 4, 2011, 08:32 PM
liten up on the lube pressure a bit that`ll help alot & ya can cut a cardboard card that`ll help more but it stiks to the base of bullets some times !

The next mold I modify I`m gonna turn a steel rod the dia. I need then cut 2 flutes in it then chuck it up in a chuck I have off the drill & turn it by hand .

I feel the rod will rite itself at the finish turnin by hand ???

Clean often & lube it ???

February 5, 2011, 10:07 AM
This is an old thread.

I cut the bevel from a Lee once just using a carpenter utility knife. if its sharp, it aint hard. It just carves right off.

DONT go too far. I got a little carried away and actually put a little bit of a flare on the boolit. Not enough too matter. It still shoots good, but at least I dont have that stupid bevel.

February 5, 2011, 11:36 AM
It's an old thread, but I'm still here watching it :) I've been shooting a lot of tumble-lubed bullets lately. You know how some people thin Lee Liquid Alox with a little mineral spirits? I thinned some down with melted Minwax Paste Finishing Wax. I have to warm it before I use it, but it dries hard and not sticky, and they don't smoke as much when I shoot them.

But someday I need to get back to using the Lubrisizer on some bullets, and I think I'll try whittling the bevel off one of my 2-cavity molds and see what happens.

February 7, 2011, 11:31 AM
To warm it, do you put it in hot water, or nuke it?

February 7, 2011, 11:43 AM
To warm it [Alox and paste wax mixture] do you put it in hot water, or nuke it?
I put the bottle in a heavy aluminum saucepan (from the Goodwill Store) along with the bullets I'm going to lube, then put it on a hotplate set to LOW until they are all nice and warm.

February 7, 2011, 12:39 PM
I just thinned mine down with mineral spirits and tried some, and it seemed to work ok, but it will take more than one coating that way. Do you remember the approximate quantities of Minwax to LLA?
I just can't get to where I like the uneven, splotchy coating the tumble lube does. Probably doesn't hurt, but it just LOOKS crappy.
I lubed some of my RanchDog 350 gr 45-70 bullets by smearing it in the grooves with my finger. Good fill on the lube grooves, with none on the nose or base. It just takes a long time. I'm thinking about doing a double dip of thinned LLA then size/seat check.
The GOOD thing about all this is that I don't have to be in a huge hurry to figure it out. My Lee HB 392gr bullet gives me 1 3/4 to 2" accuracy at 100yds at 1200 fps, so it makes the Marlin "useable". I also have a pretty accurate load using a 300 JSP..:rolleyes:
Working out a good load with the 350 RD is just going to be gravy.

February 7, 2011, 12:59 PM
About half and half. The Minwax was the bigger half :) If you can find Johnson's Paste Wax, that might work better than Minwax (some people use JPW straight; I think even for cast rifle bullets)

February 7, 2011, 01:06 PM
I might give that a try. I appreciate the information.

To sort of stay on topic, I still don't understand the notion that molds need to be bevel based. It seems totally unnecessary, and probably detrimental to top accuracy to me.... although that is simply speculation on my part.
It would seem that a good nose pour mold on a plain based bullet would give the best accuracy potential for loads under 1500-1600 fps.

February 7, 2011, 01:59 PM
I find that the bevel makes it easier to seat bullets in case mouths during loading.

I think Lee and others make custom molds relatively cheaply. You might just want to have a custom bullet mold made without the bevel.