Just cast some big bullets & gotta' question

[Blackwater]

I'd cast tons of bullets before I got my BPCR, and I thought I knew how to do it. Getting that BPCR was a great awakening to me! I found I didn't know squat about loading real black powder, and more surprisingly, found I didn't know much about casting really good bullets EITHER! This was very humbling, to say the least.

Well, a buddy sent me his Lyman 457125 mould he was having trouble casting with, and asked me to see what I could do with it. I guess I shot my mouth off about some casting stuff, and he held my feet to the fire. I hope I acquitted myself passably this time.

Cast 144 bullets, and nominal wt. was @ 513 gr. and 88.2% of them weighed between 512.2 to 513.9 gr. a + or - .85 gr. variation. This was the best I've ever achieved for wt. variation. This was with my version of 20:1, which was with alegedly soft lead from an old water tank (or boiler maybe?) from yesteryear that I got at the junk yard, with good 50/50 bar solder purchased from a welder's supply locally. Worked pretty good, I think.

My buddy didn't tell me what problems he'd been having with the mould, just to cast and tell him what kind of results I got. The problem I got (same as his) was finning on the nose, along with an apparent mismatch of the two mould halves. It was close, but the parting line was a bit too apparent, and the mould didn't close fully. The failure to close properly was initially due to using the mould on the wrong and non-fitting handles, but I used a very old old set of Lyman single cavity handles, and the mould seemed initially to close pretty well, with only a sliver of light between the halves. I guess my Mark I eyeball needs recalibrating? Took 20 of the mid-wt. lot that all weighed between 513.2 and 513.4 gr., and measured them. The noses, measured at the parting line, miked in the high .448's to .449. Pretty tight, but that parting line still showed up too prominently, indicating a small but noticable mismatch of the blocks.

The bases miked .457" plus or minus @ .0002" (two tenths), so I know my measuring with the mike was pretty good. The noses, however, miked from .4613-.4661", when measured perpendicular to the parting line, and across the mould halves (clear as mud now?) that just ain't closin' like they oughter.

I also observed some variation in how the bullets cast. Some appeared to clearly have closed more in line than on others. I'm taking this to be a problem with the alignment pin. That's my best guess, anyway. For all the casting I've done through the years, I just don't know about how to assure myself this is the reason for the mismatching, though, nor how I might go about "fixing" this mould. If Lyman won't redeem it or give him a new good one, I think he's going to chunk it, or maybe sell it cheap. He may also be willing to try to fix it, though I won't be holding my breath for that to happen. He's ticked at Lyman right now, and GOOD, too, because they cost him considerable casting, loading and shooting time.

Any observations and opinions of what to do with this mould would be welcome. I'm sure he's going to try to get his money or a new mould, but if they replace the mould, I don't think he's going to keep the new one. I think he's likely to get a good one from somewhere else - maybe Brooks or some of the other noted quality mould makers.

I've really learned a lot with this BPCR, and this mould has taught me some things, too, which is the reason I volunteered for this kind of duty for my buddy. What I don't know, and am really interested in, is:

1. How to correct a mould, should I ever need to, if this situation presents itself.

2. How do the alignment pins work, other than the obvious, and what should I look for in them to ensure that I'm just missing something on this mould? Never run across this before. The mold's "almost right," but no brass ring - not by a LONG shot!

3. Also, how much light do you like to see between the mold halves when on the handles and held to the light?

4. If the mould is warped, which I think I know CAN happen occasionally, can I use some wet or dry sandpaper (I'm thinking 400 & 600?) on some 3/8" plate glass to "fix" the mould and make the halves mate? I'm thinking I'd have to use small jeweler's files to file the vent lines back in, but I might be able to do that without screwing it up totally ... maybe.

Any options and wisdom re fixing such moulds would be appreciated. BTW, also cast some #458's from a buddy's NEI mould (the 485 gr. "Badger" bullet that allows seating out .3" to turn a trusty .45/70 into a functional .45/90), and there's hardly a visible parting line from that mould, or with my Saeco #745, either. Haven't weight sorted or measured the NEI's yet, but typically they've measured out at within .0005" or so of being perfectly round. Good moulds. I must be getting better at this casting stuff, because the wt. variation was the closest I've held since I got my BPCR and started casting these big bullets, but the results are NOT very encouraging with that Lyman mould.

Thanks in advance for any help or comments here. I think my buddy's too whizzed at Lyman to care, but .... well, you know - "A mould's a terrible thing to waste." That's what they say on TV, isn't it? [smilie=l:

[BruceB]

Blackwater, pard;

On question #2, if there's any doubt in my mind about the pins being too far out of the mould faces and thus causing a failure to close completely, I drive the pins a bit deeper into their holes (from the inner face of the block) and then try the fit of the blocks again. I take a preliminary measurement with calipers so I can tell how much movement takes place, and so I can return to approximately the original pin depth if that was not the problem. If I have a duplicate set of handles to fit the mould in question, I'll also try the mould in the other handles before modifying anything....all handles are not the same.

This is related to your question #3, because I don't want to see ANY light between the blocks. On a very few moulds, I've gotten some reasonable bullets from blocks which do show some light between the halves, but for the most part I can't see any light whatever.

Good luck to you.

[Buckshot]

...........Blackwater, the mould sounds like ***. Is it new? If it is, send it back. If you attempt any obvious alterations that don't work, Lyman won't touch it (and rightly so) and he's out a mould.

".............. The problem I got (same as his) was finning on the nose, along with an apparent mismatch of the two mould halves."

".............and the mould seemed initially to close pretty well, with only a sliver of light between the halves."

".............The noses, measured at the parting line, miked in the high .448's to .449."

".............The noses, however, miked from .4613-.4661", when measured perpendicular to the parting line,"

".............I also observed some variation in how the bullets cast. Some appeared to clearly have closed more in line than on others."

Those are all alignment issues, and some alignment problems can be traced to the handles. I hope you're using the correctly fitting ones now. Otherwise the only way the blocks align is via the 2 pins and their holes in the opposite block.

On a good set of blocks (regardless who made'em) by holding them in your hands, you should be able to mate the blocks together and with only finger and thumb pressure hold them together and see NO LIGHT between them. Also by grasping the blocks with your fingers you should not be able to get ANY rotating motion between them.

It's okay if when pulling the blocks apart if there is just a hint of resistance to their parting. This a a good fit of the alignment pin noses in their holes. I have seen many a mould that was a sloppy fit on the handles and with careless closeing the pin hits just on the edge of the hole. This can eventually wallow out the hole.

A oin nose banging on the edge of it hole can raise a bit of metal into the hole. This can lead to incomplete closing or a possible alignment issue especially if the other pin is also doing the same.

You can check for block warpage by merely laying them down on a good flat surface and trying to rock opposing corners. Also do a light check by looking under the block as it lies flat.

Sanding the faces on abrasive paper (if warped) will only give you oval boolits as you're removing metal and the blocks move closer to each other. It may just be that the blocks were poorly cherried from the git-go.

............Buckshot

[44man]

Tap the pins out a little to get the blocks closed all the way. You should not see any light between the blocks. With the handles off, try to wiggle the blocks sideways. They should not wiggle, if they do, pound the pin or pins back until there is no wiggle and no light between the blocks. It takes a little messing with but be patient and you will get it right.

[44man]

I found that the quickest way to warp a mold is to tighten the handle screws real tight. I bought a few second hand molds that were this way. I fixed them by drilling the handle screw holes all the way through and threading the rest of the upper hole. I screw in screws from the top against a brass plate in the handle slot. This will spread the block apart. Then heat it and tighten the screws a little more. Keep checking for flatness and if you go too far, it is a simple matter to put the screw in from the bottom and pull the block back the other way.
Never over tighten the handle screws!
The best molds have pins or the bottom of the block has the threads.