Under Size Mould Repair

[340six]

I have an old lyman mould that cast under size bullits.
I tried a 452 sizer die and they just are to small yes the sizer is good as it does its thing on 2 other 45 bullets. Lyman 45 Colt 250 and RCBS 45-230
A quick check with the MIC shows that 450.5-451. are what this mould 452389 {4 cavity} . I cleaned it well with some Bar keepers friend and looks new inside. Maybe it had a build up of oils so will try again today. It is white metal inside now and was burt oil/brown inside before:holysheep
This leads me to askif there are some places that repair older moulds?

[HORNET]

We've got a lot of stubborn people on here that tend to be very frugal and do their own repairs whenever possible. If you check the Lee-menting threads and stickies and get a little fine lapping compound you can fix that size issue yourself. It's only scary the first time......Make sure that you tune the alignment pins first and clean between the blocks frequently. I recommend turning things by hand for better control.
OOPS! Forgot to mention 'Beagling" which will work also (try a search for details). That would also get the size up to where it should be. Lapping is more of a permanent fix but beagling can hold up for quite a while before refreshing.
For more serious repairs, we do have a couple of members that will do re-machining of some features at times and depending on the requirements. Cost will vary.

[montana_charlie]

We've got a lot of stubborn people on here that tend to be very frugal and do their own repairs whenever possible.
If I were allowed to choose two words that best describe me, stubborn and frugal might be the ones I'd pick.

I have no need of the 'repair' lapping used to make bullets drop easily from a mould, but there IS one which I would like to 'fatten up'. It's a quality custom mould that I ordered when I (stubbornly) 'thought' I knew what size I wanted. Subsequent testing proved it needs to be four thousandths bigger...and I am too frugal to simply throw it away.

You say it's only scary the first time. This will be a one-time deal.
If it doesn't work, it will be many bucks down the tube.

I have read many descriptions of how to get it done, and realize that four thousandths is more increase than most are after. Because it is so much, I also realize that bullets cast to start the lapping will need to be replaced with larger intermediate ones as the cavity grows.

I have a somewhat different plan, which I will describe. I would appreciate any input (from experienced lappers) which might help ensure a successful outcome.

I will cast a bullet with Cerrosafe and dump it from the mould as soon as it will drop out.
I will file two flats (one either side) to hold lapping compound, and complete this by the 30-minute point...when the sample is as small as it will ever be.
I'll put the shrunken bullet in the mould, and clamp it snugly shut...then turn it by hand to distribute some lapping compound throughout the cavity.

Near the one-hour point (when the bullet has reached actual cavity dimensions), I will give it a few turns every twenty or thirty minutes...as the sample expands.

Cerrosafe reaches it's maximum size after something like 24 hours. I may even need to wake up during the night (a few times) to keep up with the expansion.

My hope is to reach the desired diameter by only using one lapper which will never get bigger than the goal...and (because it's harder than lead) will maintain the purity of it's original shape.

If the cavity doesn't get quite as big as the four thousandths desired, I have several 'normal' bullets of the correct diameter that can be used (I hope) to do the final polishing with something like Comet.

Any further suggestions...?

CM

[BCall]

I'm not sure I'd do 4 thou enlargement by lapping. Personally I would hate to see an expensive mold go bad because I did something wrong. I know that there are people here that would feel fine with it, but I am not one of them. I have lapped molds 1-2 thou, and was OK with it, but would not want to go larger. I knwo frugal is the key, but Eric at hollowpointmold.com offers drive band enlargement for a reasonable price I think. $25 setup plus $5 per band. I don't know how much the mold originally cost, but for an expensive custom mold, I would be more inclined to seek out his services if I needed to go up that much on an expensive mold. A cheap Lee mold, yeah I'd lap it, but not one of my custom molds. JMHO, Billy

[montana_charlie]

I should probably add some detail...
This is a mould which throws a paper patch bullet with smooth, parallel, sides.
It currently makes a .450" diameter bullet, but I need .454".

It is a Steve Brooks mould with an 'elliptical' nose and weighs in the neighborhood of 540 grains. He actually cut the wrong nose in this mould..and wouldn't make it good.

If I can get it bumped up, it may be worth experimenting with. Otherwise it's $160 poorly spent.
CM

[dragonrider]

Charlie I think that your plan might work but that you may have to repeat the process more than once, I doubt the first cast you make will get you the 4 thou you are looking for but the cavity should be bigger necessitating the casting of another.

[theperfessor]

Montana charlie

I think your idea of using a material such as cerro-safe might work. It will be interesting to hear how it works.

Since you're dealing with a simple cylindrical form with a specific end shape (no lube grooves or cut shoulder I assume?) it might be worth trying to use hot melt glue and embed the lapping compound in it. Still might have to make several laps, but it might cut the time down. And I bet if you got a good fill you could put a little downward pressure on it and polish the nose and cause the lap to swell a little bit and cut a little bigger on the sides as well.

I'd watch out for rounding the corners off at the sprue cutoff point whether its a base or nose pour.

Just a thought, good luck to you however you do it.

[montana_charlie]

Charlie I think that your plan might work but that you may have to repeat the process more than once,
You could be right, and time will tell. But, here is the reason I have hope that one time will do it.

In a discussion about how much Cerrosafe actually changes size over time, a guy posted this...

For example, a casting of my 40-65 Ron Long chamber neck measured 0.4305" one hour after taking the cast.
24 hours later the neck measured 0.4330"

If the chamber cast started at .430"...and gained about three thousandths in 24 hours...I'm hoping a .450" casting will gain (most of) four thousandths in the same amount of time.

If I keep grinding away as the bullet grows bigger, I hope to end up near the diameter I want.

What I am seriously hoping to avoid is a situation where the sides of the mould develop different diameters at different points along their lengths...humps and valleys, as it were...or a fat middle and a skinny base.
I'm hoping the hardness of Cerrosafe (over bullet alloy) will prevent that.

Montana charlie

I think your idea of using a material such as cerro-safe might work. It will be interesting to hear how it works.
It's good to hear somebody does...
I expect the slug to grow in length (as well as in diameter) so that may work to keep the base matching up with whatever is happening deeper in the cavity.

CM

[340six]

Well I was realy posting to see if there was company or member here that did that kind of work. As Someone who does would be best and have me stick to things I know.
Last night I cleaned it well with my old tooth brush and bar keepers friend to see where I was at with the Micrometer.
Then posted this this morning to see if anyone did.
I tried the cast bullets with compounds but the bullets gave way before they removed much if at all. Really all they did was polish.
So went at it like I do to sand polish aluiminum. Figured if I can do that maybe it would work out.
Some of my work on as cast heads pilished out for a 12.3:1 340six pack engine.
http://i234.photobucket.com/albums/ee87/fast340six/trans/18527486_22573996.jpg
http://i234.photobucket.com/albums/ee87/fast340six/trans/polishtrans1.jpg
Another set of heads I did for a small block stroker 340 stroked to 423ci
http://i234.photobucket.com/albums/ee87/fast340six/trans/polishedtrans2.jpg
http://i234.photobucket.com/albums/ee87/fast340six/trans/eddie4.jpg
So "Today" I cleaned up the one hole that had bad spot, with some tapered sand paper rolls on the button heads of the mould with the die grinder. i did it to all 4 so they would all be the same.
Then made a Buff out of a bob for die grinders by spining it and cuttting it down with a sharp wood chisel.
Followed by sand paper. Once I got the right shape and size I went to work with the grease based black emery. I cut some with the black emery cleaned it up measured, repeat did not want to go to far.
Followed up with gray emery, and white rouge to polish
Ok sorry high jacked my own thread back to the mould
This picture shows the uncut bob buff and the one I cut down to the bullet shape that was put to work with the die grinder.
http://i234.photobucket.com/albums/ee87/fast340six/Bullet%20moulds/bulletmoulds001.jpg
http://i234.photobucket.com/albums/ee87/fast340six/Bullet%20moulds/bulletmoulds002.jpg
The marks on the flat part are not really scratch marks, but trash I had on my finger that wiped right off with a rag.
I cut some with the black emery cleaned it up measured, repeat did not want to go to far.

http://i234.photobucket.com/albums/ee87/fast340six/Bullet%20moulds/bulletmoulds009.jpg

[montana_charlie]

340six,
You made some very pretty cavities. Were you able to keep sharp corners on the driving bands?

Sorry for my hijack. I thought your question had been covered, and I could take up space on the tag end without starting a new one.
I'll refrain from any more comments until you say you're done...

CM

[340six]

Yes the sharp conners are still there. Yes I am done lube and size on a little over 500 now. I made up some of them little wad cutters for thursday night to see how this load works out.
If they do not feed in the 1911 they will be great in the Ruger Black Hawk

[jsizemore]

340six, I had your exact problem with a new mold. My solution was to add 1.5% pewter to my WW's and to keep my casting temp below 650deg. I shoot for 640 and the pot cycles 630 to 650. Gained a couple thousandths over the use of straight WW's and casting just shy of 700deg. Hope this helps.

[theperfessor]

Very nice work and good photos. I bet the bullets just jump right out.

[340six]

Any Idea of age of this mould? Says Ideal not lyman so it is old maybe they made it smaller for who ever?
Thanks!
And yes they jump right out

[brettb75]

I would definately give Eric a call at hollow point service he is a top notch guy