Undersized boolits?

[novalty]

Well ran into a little snag with my Lyman 452374 cast boolits. Cast up a few in my first session, and thought I had about 60 keepers. Ran them through my RCBS LAM2 with my .451 sizing and got a bunch of them done, when it occured to me they were sizing extremely easy, and I didn't see any marks from sizing. Measured them with my caliper and they were measuring around .4495 to .451. The boolits look good, just undersized. Not sure it is because I am using straight COWW's or what.

[462]

That alloy shouldn't be the problem -- not .0025" too skinny.

Is it a new mould? Return it if it is, requesting postage reimbursement.

If it's a used mould, it can be lapped or "beagled" (search).

For what it's worth, my 4-banger drops them at .454".

[RobS]

If it's a new Lyman mold welcome to Lyman quality control. The only Lyman mold I would by these days is a used one that I know how it casts. I sold an older Lyman mold that also cast at .4535-.454 and the front drive band was full diameter as well unlike many molds that drop small above the front drive band as well.

As 462 mentioned if it's new send it back to where it came from.

[novalty]

Well I traded with another forum member, that said they had cast about 1,000 bullets with, for an older Ideal mold that I didn't think I'd use. I'll try it out in another casting session, and go from there I guess.

[robpete]

I had a newer 4 cavity that dropped @ .451(my Kimber likes .452's). I could not get that thing right. Ended up selling it and going with an Accurate H&G 68 instead.

[popper]

I hear this comment frequently. A simple, inexpensive and possibly temporary (until you fix it or get another) could be Piglet's powder coating method. It will add a few thousandths to diameter and eliminate leading. Saves recasting that 20# or so that didn't come out quite right. Yes, they do shoot good. Not old school but works.

[novalty]

I have shot this style bullet before sized at .451, and they shot accurately and I didn't notice any leading issues with my S&W 1911. My father-in-law that introduced me to reloading & casting, had cast me about 400 boolits with his Lyman 452374 mold, and I sized them and shot this spring without issues.

[runfiverun]

you can try bumping your alloy with some tin.
you can beagle the mold.
you can lap the mold.
you can try pressure pouring the mold.

if you want the mold to work with what you are doing those are your options.

[Larry Gibson]

Add 2% tin to your alloy and cast at 725 degrees. Open spout, if using a bottom pour, and get the alloy into the mould as quick as possible. Be generous with the sprue to the point of run off. That should give bullets to nominal diameter of .452. If using a Lyman, RCBS or Rowel dipper follow Lyman's directions (in their manuals on how to cast sections). If using a Lee dipper.....get a Lyman, RCBS or Rowel dipper......

If you want to send the mould to me to test I have a standing offer on so called "undersize casting Lyman moulds".

Offer; I test with Lyman #2 alloy (what the mould is made for) or and equivelent using COWWs + tin. If the mould is in good condition (I think we can agree that an abused mould is just that) and casts to nominal diameter or over I send mould back with alloy instructions and casting technique along with several cast bullets. If the mould does not cast to nominal diameter with Lyman #2 alloy I will buy the mould from you for what you paid + shipping to me. That is a win-win for you and I take the risk. If you want to take me up on the offer PM me for my address.

Larry Gibson

[novalty]

Add 2% tin to your alloy and cast at 725 degrees. Open spout, if using a bottom pour, and get the alloy into the mould as quick as possible. Be generous with the sprue to the point of run off. That should give bullets to nominal diameter of .452. If using a Lyman, RCBS or Rowel dipper follow Lyman's directions (in their manuals on how to cast sections). If using a Lee dipper.....get a Lyman, RCBS or Rowel dipper......

If you want to send the mould to me to test I have a standing offer on so called "undersize casting Lyman moulds".

Offer; I test with Lyman #2 alloy (what the mould is made for) or and equivelent using COWWs + tin. If the mould is in good condition (I think we can agree that an abused mould is just that) and casts to nominal diameter or over I send mould back with alloy instructions and casting technique along with several cast bullets. If the mould does not cast to nominal diameter with Lyman #2 alloy I will buy the mould from you for what you paid + shipping to me. That is a win-win for you and I take the risk. If you want to take me up on the offer PM me for my address.

Larry Gibson

Hello Larry,

I may take you up on that in the future, but as mentioned this was from my first casting session. I am not saying it is the mold, just that I got undersized boolits, and trying to get some tips for my next session to try out. I am casting from a RCBS Pro-melt-which is new as well, so I was getting used to that and adjusting the flow stop point. Once I get my smelting equipment back from my brother-in-law, who just melted down a couple hundred pounds of wheel weights, I'll put my Lyman thermometer in the pot. But my first session I cast with the Pro-melt set to around 725 degrees. I didn't smoke my molds or use any kind of spray, they were heated on my hot-plate at a medium setting. The bullets dropped pretty freely from the mold, which should be expected be undersized, and for the most part looked really good.
They are on the left side of photo:
http://i100.photobucket.com/albums/m11/novalty1970/Reloading/Firstcast_zps5462c59b.jpg

[Duckiller]

Somewhere I have seen and read a write up on how different alloys will effect boolit diameters. I have looooked everywhere I can think of and can't find it now. I have a .32 WS/8mm mold that I would like to cast a bit smaller and some 45-70 molds that I would like to cast a little larger. If anyone has information on how alloy or casting temp can effect final size could you please post where you found it. Thank you.

[Huskerguy]

I have the same mold. At least I think I do, mine has an F at the end if that makes a difference. I had the exact same experience and couldn't figure out what I was doing when sizing. I started measuring several cast bullets and found all sorts of differences. The largest measurement was exactly .451 with flat spots on both bullets from the mold. I was wanting .452 bullets to start with. I didn't buy this mold so I can't send it back. Guess I will look up "beagle" and "lapping" and see what I come up with.

Update: someone is going to have to give me more info on these two terms because I can't seem to find enough to learn anything.