Fly cut 200gr SWC mold bullet weight ?

[milprileb]

So I have been spinning around trying to find a solution to that bevel base on the Lee 200 gr 45acp SWC (#68 clone) bullet. One option is a board member can
fly cut the mold and eliminate that BB entirely but the bullet will be lighter.

Any idea how light a 200 gr bullet would end up if BB were removed ????

I ask as I own a Lyman 4 cavity 185 gr mold and I could end up with little to gain
for fly cutting the Lee mold.

Granted I would have a lighter mold and a 6 cavity.

Your thoughts please.

[casterofboolits]

My experience, with my alloy, has been a reduction of one grain per .002/.0025 removed for a 45 cal boolit.

I modified two old style H&G # 68 (a four and an eight cavity cut with the same cherry) 45-200-SWCBB to drop a 185 grain boolit. I have also modified several pairs of Lyman four cavity moulds to drop the same weight boolits. 9mm thru 44. I did this with asurface grinder and a mill with fly cutter. The surface grinder gives the best finish.

[deltaenterprizes]

Surface grinder is not suitable for aluminum.

[zxcvbob]

How bout just cutting it out with a sharp pocket knife?

[fecmech]

Put a BB boolit in a vise, file off the BB and weigh the result.

[BMWrider]

Couldn't you lightly file out the top inside of the mold where the bevel base is formed? Maybe use a small reamer to knock off the edge? Seems it would be a lot less involved than grinding down the whole top of the mold.

[M-Tecs]

Surface grinder is not suitable for aluminum.

When you surface grind aluminum you normally use a softer wheel. They design wheels specifically for aluminum. To hold the part you use a vacuum chuck, block it in with steel parts, use double sided tape or use commercial clamps designed for surface grinding non-ferrous items on a magnetic chuck.

For something as small a mold block you can get away with using a general purpose wheels. Flood coolant is best but kerosene in a spray bottle works for small jobs. If the wheel starts to load up you can hear it. Just dress again with a course dress.

[HollowPoint]

I've never had to mill off the Bevel Base of any type of bullet mold. The closest thing I've done
is open up a Gas Check shank so my Gas Checks wouldn't slide off before sizing.

I don't think that milling off your Bevel Base would alter the weight of your bullet enough to make that big of a difference but, as I stated, I've never done it myself; just speculation on my part.

I base my statement on the fact that even with no alterations, the "As Cast" weight of your bullets as they drop from the mold can vary to a certain degree. If you just remove the ridge that forms the Bevel on the base of your bullet, the weight issue will be minimal at worst.

I'm not talking about milling off the top of your mold blocks to eliminate the Bevel-Base-Forming-Ridge; I'm talking about just opening up the ridge to the diameter of the rear driving band.

Even if you open it up a hair to big you can still size it down to your preferred diameter.

Another idea is to send it over to Eric at hollow pointing service and he can do it for you. He does top notch work.

HollowPoint

[mdi]

I have a Lee mold, bevel base 230 gr. TC. Just fot grins (that old "I wonder what will happen if..." thinking) I drilled out the base in one of the cavaties. Mebbe a 11.5 mm drill. I did it by hand but, a good drill press and a good drill vise would make the job a snap. My drilling job came out a bit oversized, mebbe .002" out of round, with a hint of chatter, and all the problems come out in the sizing die (Lee .451"), but careful use of a drill press would eliminate my mistakes...

[casterofboolits]

My experience, with my alloy, has been a reduction of one grain per .002/.0025 removed for a 45 cal boolit.

I modified two old style H&G # 68 (a four and an eight cavity cut with the same cherry) 45-200-SWCBB to drop a 185 grain boolit. I have also modified several pairs of Lyman four cavity moulds to drop the same weight boolits. 9mm thru 44. I did this with asurface grinder and a mill with fly cutter. The surface grinder gives the best finish.

I've only done this to iron/steel moulds. Never tried Aluminum as I don't use any.

[GabbyM]

Have you thought about making a pin for the die with a bevel to match the bullet to avoid lube leaking?

[HeavyMetal]

No one seems to have asked this question so let me: Why are you doing this?

To gain a lighter boolit? If so use the Lyman you already have.

To "gain" production over the Lyman 4 banger? If so buy a second Lyman 185 grain 4 banger mold and use both when casting.

Some one told you BB was "bad"? Shoot those "bad" boys and see if they meet your needs before you spend hard to come by cash!

You'll pardon me for playing a little " Devil's Advocate" but I am unclear as to the proposed purpose of the modification. I have a pair of the Lee 68 clone molds and they shoot to beat the band with the correct load.

Please advise.

[ItZaLLgooD]

I modified a Lee TL230-452-TC mold. They cast to approx. 235 grains in WW. I wanted 185 grains. I had to take way more off then I thought I would to get the weight down, somewhere around 0.090" - 0.100". I ended up leaving it at 195 grains because it was getting pretty short and I started to worry about accuracy.

I turned out pretty well and they shoot great. Lee molds are cheap enough that I didn't mind experimenting a little. I say mill some off there if you want to.

[pinshooter]

I did this to my Lee 452-200-SWC a few years ago.

Using WW + 2% tin:

w/bevel base 200.9 gr

w/o bevel base 176.6 gr

Since these were cast several years apart, the alloy used may not be exactly the same, but this gives you a good idea of what to expect.

The reason I had for doing this was a Lyman 450. I go tired of wiping the lube off the base of every boolit. Later I sold the Lyman and got a Star. Money well spent.

One other thing you will need to do is to shorten the screws that hold the handles on by the same amount. Even if it looks like there is clearance between the end of the screws and the mold, there won't be when the mold gets hot and you squeeze the handles. I learned this the hard way.

Pinshooter

[RobS]

Many lee molds will cast a bit over their weight. I milled off the top of the Lee 452-230-TC that weighed in at 236 or 238 grains IIRC. When done the mold was 10 or so grains lighter.

[milprileb]

The reason I had for doing this was a Lyman 450. I go tired of wiping the lube off the base of every boolit.

That is exactly why I am interested in doing this to my mold. However, if result is a 180 gr bullet and I already have 185 gr mold ..... this is not worth trying

[WHITETAIL]

I would drill out the BB and be done with it.

[44man]

To fly cut the top of the mold is the wrong way. Most BB problems are caused by the shorter drive area for the twist. You will not change that even though the boolit is lighter because most guns do not like a lighter one.
Some will say it is overall boolit length but I am not convinced, there is more to matching twist then that. I think it is a combination of things.
I removed the BB from one .357 boolit by hand but can't remember what I used. It took a final lapping with a brass lap though. I did not cut all at once to size.
That alone cut groups by 2/3's.
I don't own a .357 but it is now my favorite boolit for my friend's guns. It is now what the boolit should have been.

[milprileb]

Hold presses, I am not focused on driving bands and twists. The focus is eliminating the way BB mold allows a grease ring of lube to build up and need cleaning off every time you lube a bullet. Eliminating the BB to eliminate this irritating lube on the base is the focus.

Lets not jump to off the cliff and expand the focus on the thread please.

[Doby45]

Take a sharp knife and curl off the BB of just one cavity and you will see how easy it is. One cavity will take about 2-3min if you want to make it nice and purty. It truly is not rocket surgery as the Lee aluminum is nice and soft.