Mold tune-up?

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  • Last Post 01 October 2018
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max503 posted this 17 September 2018

Here's my Lyman 225415 mold.  I cast up a small handful of bullets this evening - and I'd forgotten how much of a PITA this mold is to use!  I've had to beat the hinge pin in order to get the bullets to drop out of the cavities.  In addition, the sprues want to stick to the cutter plate.  Those have to be tapped, and sometimes pried off.  I ruined a few bullets that had to be pried out of the opened mold blocks.

I use Bullplate as directed to lube the bottom of the sprue cutter, top of the blocks and the alignment pins and holes.  

It looks to me that the blocks don't match perfectly.  One is a couple thousandths above the other at the top surface.  I think there could be some burrs in the cavities. 

Should I maybe look into flattening the top of the blocks and the bottom of the sprue cutter.  If so, how would I do that?

Can I polish out and de-burr the cavities?  If so, how?

One cavity fins on the nose.  I'll try to post some pics.  Thanks in advance.  These bullets shoot ok.  But I think they can do better.

I like pics.  Can you tell?  See that shiny line in the first pic?  I think that's where the sprue plate rubs which keeps the plate from sealing to the top of the blocks.

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max503 posted this 17 September 2018

I think I need to 1) polish off that shiny line on the top surface of that one block, 2) polish out and deburr the actual cavities, and 3) polish/flatten the bottom of the sprue plate.  

How would I do that?  I've never done it before.

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David Reiss CBA Membership Director posted this 17 September 2018

It appears that this mold has been abused as there appear to be several issues that I can see from the photos. I am certainly not accusing you of this abuse as you may have purchased it used. The sprue plate can be polished with emery cloth on a thick piece of glass. You can attach the emery cloth with contact cement. As for the the cavities you can spin a bullet coated with grinding compound such as JB paste or Clover grinding compound. However there appears to be some heavy nicks around the bases of the cavities. This would take a machinist to mill or grind the top of the blocks flat. Anyone please correct me if I am wrong. 

This mold is fairly common and many are available on Ebay or Gunbroker, you might just consider replacing it. 

Max, I apologize if my comments sound harsh. 

 

David Reiss - NRA Life Member & PSC Range Member Retired Police Firearms Instructor/Armorer
-Services: Wars Fought, Uprisings Quelled, Bars Emptied, Revolutions Started, Tigers Tamed, Assassinations Plotted, Women Seduced, Governments Run, Gun Appraisals, Lost Treasure Found.
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joeb33050 posted this 17 September 2018

Loring Hall told me, years ago, that molds needed inspection and adjustment after every casting session. Dowel pins tapped to eliminate play in mold halves, all lead cleaned off, sprue plate off and burrs removed, all other burrs removed, etc. I did this for years, and it seems to have helped. Some molds don't drop bullets. Bronze wire brush or pencil lead on edges helps for a while.

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max503 posted this 17 September 2018

I'm wanting to polish the mold and I'm wondering how to do it.  Can you guys please expound on the de-burring and cavity lapping processes?  That's where I need help.

Yes, I bought this mold used.  No, I don't think it's been abused.  The camera I used is very effective at picking up detail at close range.  Those are normal tool marks.  They just look bad because of the camera's abilities.  Modern technology is wonderful.  That camera cost less than $20 and it's attached to a 20 foot cord for looking down holes, pipes, etc.  It's called an endoscope and I got it off a website called DealExtreme.  Here's a couple shots of a fired 22 case:

 

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pat i. posted this 17 September 2018

I'm gonna go with Dave that that molds been beaten up a little.....or a lot depending on what your idea of beaten up is. In the long run you might be better off putting it on the shelf and looking for a replacement.

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Ken Campbell Iowa posted this 17 September 2018

hi ... if all else fails, i will give it a shot ... basically as mentioned above ::  mill blocks, lap sprue plate, polish cavities ...    tighten alignment as possible ...       by the photos, you might lose 3 or 6 thousandths on the bullet base :::   will the gas check still fit ??? ....

$5 return postage and it is possible it is not recoverable.  pm me if.

ken

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max503 posted this 18 September 2018

I just want to polish the cavities but not remove any appreciable amount of metal.  I guess you stick a nail in the base of a bullet, coat the bullet with valve grinding compound or toothpaste or some other grit, and spin it in the cavity?  Anybody done something like this?  I just want the bullets to drop out of the cavities easier.  Those small slugs don't have much weight and they want to stick in the mold.  

Then I want to polish the base of the sprue plate and the top of the blocks.  Any suggestions?

It makes good bullets.  I shot this group a week or so ago at 100 yards from my 10" Contender Hornet off a wood block rest with a 4x scope.  That horizontal spread is from my pulse.  Thanks.

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max503 posted this 18 September 2018

Maybe I should make a little steel wool q-tip thingy and spin it in the cavities with a Dremel or drill press?

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GP Idaho posted this 18 September 2018

max503: No point in holding back at this point. Get right after it and get it  cleaned up. Gp

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Hornet posted this 19 September 2018

I'd recommend taking Ken Campbell up on his offer. That abused baby needs some serious massaging and it takes practice to successfully resuscitate one that far gone. It's NOT difficult, but it does have a learning curve.

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frnkeore posted this 19 September 2018

I'm a retired machinist, of 44 years. I've fixed many molds, including misaligned block halfs.

Yours is as abused as I've ever seen. My guess is that the abuse came to be, because the edges of the cavity's have burrs. The way to fix that is de-burr it CAREFULLY, with a Exacto knife. Do the same to the burrs that protrude, into the GC shank area.

The sprue plate can be polished as David says. Use course emery of 60 grit and try to get the bottom edges sharp. You will also need to polish the tapered sprue area, on the top, as the rough machine marks are what mostly causes sicking. After doing that, the sprue hole may be almost the size of the base.

Replacing the pins or pushing them in deeper, may bring back the top misalignment. That would be the first thing to try. The female side will be warn oblong and the new pins will need to go deeper, until the halfs stick a little or you can counter sink them, to get to the part of the hole that is still round. I would recommend new pins, if you do that.

Even after you do all of that, the mold will never be worth more than $20 to anyone that knows what a mold should look like.

If I had that mold, I would put new, over size pins in, square the top and bottom and re-cut it to a larger caliber.

Frank

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Ross Smith posted this 20 September 2018

I just had a machinist shorten a plain base mold to get shorter bullets. I started with a good newish mold and it still cost $50 to mill the blocks and move the sprue plate set screw holes. My advice would be to take that $50 bucks and add to it and buy a new mold. Or just try it yourself, you won't be out anything.

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max503 posted this 24 September 2018

Thanks, everyone, for the help.  I've decided to tackle this job by myself.  

The mold gives me good bullets.  (See my post with the blue target.)  Also, I wrote an article for the FS issue 187 about the luck I was having with this bullet in my Hornet.  If it gave me peach-basket sized groups at 100 yards I would think different, but it works.

Aren't there people who pride themselves by getting good bullets out of old, rusty molds?  And mine ain't even rusty.  

I think those high-definition pictures make the mold surfaces look much worse than they are.  So far I have kissed the top surfaces of the blocks and the bottom of the sprue plate with a very fine file.  Didn't take much to even up the top surfaces.  (The bottom mold surfaces are completely even with each other.)  Next, I'm going to lightly polish the cavities and edges with one of those white fiber wheels in my Dremel.  Haven't decided yet what to use for a polishing compound.  I'll do it some day when my nerves are really steady.

Thanks again for the help and I'll post a follow-up when I'm done with the tune-up and have had a chance to melt some more lead.

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Ken Campbell Iowa posted this 25 September 2018

hi max ... when power wheel  polishing across a hole, you might/will polish a radius into the hole junction ....  make a oval fin on the bottom of the bullet ..   .  

i would not use a wheel, just polish against  a flat surface ....   

... and stop fixing it just short of perfect .... heh ....

hey, and leave a little rust on it !!!

ken

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max503 posted this 26 September 2018

Thanks again for your offer, Ken. I'll be gentle with it.

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delmarskid posted this 28 September 2018

I have brought a couple molds back with stoning and Emery cloth. I would stay away from power tools not enough material had to be removed for mine at least. You can pull a piece of tissue paper over the molds cavity edges to find burrs and take them off carefully to not leave a radius that will show on your bullets. The sprue plate can be replaced if it needs it. The fins that I think I see on the noses of your bullets could be from the molds blocks not closing squarely. If the alignment pin holes aren't too out of round the opposing pins can be tapped inward a bit and this will probably go away. I love fixing things with simple hand tools. I've bought broken stuff just to see if I could make it work.

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max503 posted this 28 September 2018

I've cleaned-up the tops of the blocks and the bottom of the sprue plate.  All I have left to do is deburr the cavities.  I'm meditating on that. Yes, the edges are prickly.  I ran a q-tip over them.  I need to lightly deburr them.  I won't use the Dremel.  There's got to be some itty-bitty burrs that are keeping those itty-bitty boolits from falling out of the cavities...……...

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delmarskid posted this 29 September 2018

If the mold were mine I would lay a very fine flat stone across the faces and just slide it back and forth with finger tip pressure. If there are rough spots inside of the cavities I might try to locate them and maybe sort of burnish them down with the end of a small dull edhed screw driver. Easy does it buddy. We don't want to make things worse right?

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delmarskid posted this 29 September 2018

I have a Flintstone phone so I can't edit. I meant edged. You may be able to lift the burr at the cavity edges and then stone it down. It might take a few cycles sort of like taking the wire off of a knifes edge

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max503 posted this 30 September 2018

Well, I smoothed the tops and faces of the blocks and bottom of the sprue plate, then I deburred the cavity edges. I polished the sprue hole divots.  I think the burrs were on the gas check band.  Yes.  This mold had been abused.  It is old.  I've got the old style cardboard box it came in.  Don't remember where I got it.

But I tried it out yesterday and it worked much, much better.  The bullets didn't need to be beaten or pried out of the cavities.  My only question is - do I leave bare metal where I filed and deburred?  The patina is gone in some spots.  Do I just leave it like that?  I oil my molds for storage.  Thanks.

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Hornet posted this 01 October 2018

I've cold blued some and left others bare. It doesn't really seem to make much difference. You'll probably see the color change on it's own after a few hours of run time. It'll also run even better then. A coat of naturally developed high temperature oxidation does wonders.

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