need to add .002 thousandths of a in,

[odfairfaxsub]

without beagling i was thinking about lapping the drivebands like people do with lee molds but this is a steelmold. what have you used sucessfully as a compound.

[DLCTEX]

I have used fine valve grinding compound. Use two steel plates and roll the boolit between them with valve compound in a thin layer on the bottom plate. This will embed the compound in the lands only. Wipe off excess before using. Steel will take some work, but it can be done. I did an aluminum mould without wiping the excess off and enlarged the bore riding nose also.DUH! Oh, use oil to aid in the cutting, works better. For .002 I would try some medium or maybe even course to start.

[odfairfaxsub]

thanks texas

[Mal Paso]

I used 320 grit Diamond powder from Arrow Lapidary. 25 ct. was about $25 + shipping but you can buy smaller amounts. Diamond cuts faster and makes it less of a chore. I rolled it into the drive bands of a soft lead bullet between 2 steel plates.

[odfairfaxsub]

then ran the bullet in a drill right?

[Wolfer]

I used 220 grit from a Wheeler bore lapping kit, drilled a small hole in the base as close to center as I could without measuring and screwed the arbor from my Dremil polishing wheel into it.
Kept it flooded in dish washing soap and turned it real slow. Took a while but I got it there.
This was a Lyman 429-421
As the laps got too loose I would just make another, probably took about 3 per cavity

[odfairfaxsub]

luckily its a single mold. what was the finish with the 220 grit? was it one that broke itself down as used

[mooman76]

Someone (I can't remember who)here recommends a method where you place a nut on top of the mould without the sprue and pour your lead in. Then you turn the nut with a wrench with you lapping compound in place as you would the drill. Stopping to wipe out the excess lapping compound that gets between the mould halves. It actually works better and faster than you would think.

[runfiverun]

if the mold is 358 or larger then the lapping compound on the boolit and a wood screw in the base will work.

if it's a long skinny boolit.
then pouring through a warmed up 1/4"/5/16ths" nut on top of the mold and turned with a wrench or nut driver is the way to go.
i just use some valve lapping compound [in oil] from the napa for about 7 bucks.

i find it best to lap a warmed up mold.
clean
pour till i get good boolits again then make another lap and do it again.
clean
then pour and measure a couple of boolits.
work slowly [it took me most of a week to do a 4 cavity mold .002]
i finish the mold off by lapping with whitening toothpaste.

[ciphery]

Good thread, I'm off to find more info about the same thing.
I own a 1955 Polish made M44 in near mint condition.......except she has a .315" bore dia...... .312" is what she is supposed to have.
Any how, finding 316 molds is impossible so lapping is my best bet.

[NoZombies]

Good thread, I'm off to find more info about the same thing.
I own a 1955 Polish made M44 in near mint condition.......except she has a .315" bore dia...... .312" is what she is supposed to have.
Any how, finding 316 molds is impossible so lapping is my best bet.

The good news is that here, there are makers who build custom molds. Including .316"

[Mal Paso]

Good thread, I'm off to find more info about the same thing.
I own a 1955 Polish made M44 in near mint condition.......except she has a .315" bore dia...... .312" is what she is supposed to have.
Any how, finding 316 molds is impossible so lapping is my best bet.

If you don't have the mold already consider a custom one. CNC mold makers can run the cherry in a little bigger circle. Not sure how Accurate Molds is set up but you can probably get one made for the same money as fixing a new one. Although I treasure my hand lapped Lyman 429421, that's a lot of work to get something almost as good as if it was cut right the first time.

[runfiverun]

noe just run a 316299 mold i would love to have for my argies, airc the nose was 305 and the body 316.
i have done fine with the 314299 at 313 sized and checked and 304 on the nose, but a bit bigger would let me up the speed some more.

look in the vendor section and see if he still has some.

[ciphery]

A buddy of mine gave me a LEE 165grn 7.62x39 mold for Christmas so......
I've seen a 316 mold before, problem has always been no gas check or round nose flat point.

[HangFireW8]

without beagling i was thinking about lapping the drivebands like people do with lee molds but this is a steelmold. what have you used sucessfully as a compound.

.002 of one thousandths... So, two millionth of an inch shouldn't take very long. :kidding:

I use Clover, grit depends on how far I have to go.

HF

[GL49]

Yesterday's project:

I've got a Lee six cavity .452 230gr TC mould that would cast .4505 to .451 at the parting line, .451 to .452 across the bullet, depending on the cavity. I wanted to size to .452 using WW's, what to do?
I used 320 grit clover compound in a grease base, drilled the end of a bullet cast from the mould, tapped it for an 8/32 machine screw, installed a screw, cut off the head and spun it in ONE cavity with my cordless drill at low speed for 25 seconds. Using the blunt end machine screw insured that it wouldn't screw through the bullet and ruin the cavity. Scrub-a-dub-dub in the sink with a toothbrush, hot water and dishwasher soap (had to do it twice, the oil in the grease/clover compound mix is tough to clean), it casts .453 at the parting line, .4535 across the bullet.
Now all the driving bands clean up in my .452 sizer, no sign if it not hitting anywhere. The bullet just falls out of the mould. Next step is to polish with Comet or toothpaste, and since I know it works and haven't reduced my six cavity mould to a five cavity, I'll do the other five cavities, using as cast dimensions from each cavity to gauge the time I need to spin the bullet in each.
Don't know how long a steel mould will take, but aluminum cuts pretty quick. I can tell you the process does work, and seems to enlarge more at the parting lines, which is what I needed and of course were smaller anyway.
I've got two more undersize Lee moulds that will get the same treatment, one of which doesn't want to drop the bullets without some encouragement.