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View Full Version : Alloy and temperature affect on as cast bullet diameter??



dogdoc
05-14-2014, 10:34 PM
I have a Lyman 429421 4 cavity mold that cast bullets with wheelweight alloy at about .427 inch diameter. I would really like a much larger bullet for my S&W model 24 and 624. How much larger would I expect by adding say more tin? What kind of variation in diameter is realistic with different alloys or casting temps? Thanks

Moonman
05-14-2014, 10:42 PM
dogdoc,

You can look under the thread CLASSICS AND STICKY'S look for
MOLD ENLARGEMENT BY "BEAGLING".

62chevy
05-14-2014, 10:43 PM
Your mold may be to hot. Wheelweight alloy increased the size of my boolits from .452 to .453 same with my 30 cal from .309 to .311 both something I can work with.

DrCaveman
05-14-2014, 10:48 PM
I dont want to sound discouraging, but dont expect to gain too much from alloy & temp adjustment alone. Beagling or lapping have been the only ways ive found to consistently enlarge the boolits.

Check out the sticky called "something i learned about temp last weekend" and youll get the skinny

You might squeeze a thousandth...or two... From alloy adjustment. Temp adjustment is somethng im still working on. But trust me, it is important

As for alabama, i was just in the birmingham area last weekend for a cousins wedding. Beautiful place, nice people. If you like 'bama, check out Oregon. I think they have a lot in common.

Larry Gibson
05-15-2014, 01:08 AM
Add 2% tin to your COWWs. This will give you a proper ternary alloy with a balanced SbSn mixture in the lead for better fill out and an over all better alloy.

Cast with alloy temp at 725 degrees.

Use cast tempo just fast enough so bullets don't frost.

With both bottom pour and ladle fill cavity quickly and leave a good large sprue even if alloy runs off sprue plate.

Your Lyman mould is cut for a ternary #2 alloy not COWWs (your COWWs are tin poor BTW). By doing the above you should get a minimum .429 bullet if not a .430 - .431.

Larry Gibson

ShinyPartsUp
05-15-2014, 01:50 AM
Add 2% tin to your COWWs. This will give you a proper ternary alloy with a balanced SbSn mixture in the lead for better fill out and an over all better alloy.

Cast with alloy temp at 725 degrees.

Use cast tempo just fast enough so bullets don't frost.

With both bottom pour and ladle fill cavity quickly and leave a good large sprue even if alloy runs off sprue plate.

Your Lyman mould is cut for a ternary #2 alloy not COWWs (your COWWs are tin poor BTW). By doing the above you should get a minimum .429 bullet if not a .430 - .431.

Larry Gibson


I am new to casting and about to finally (after getting materials and equipment together) going to start casting. I had heard all of this in different places, but never so succinctly and easy to comprehend in a couple sentences. Thanks.

44man
05-15-2014, 07:35 AM
Larry is correct, once you get to frost the boolits will be smaller. A little tin helps the alloy. Water drop and age a week or so and you can grow them about .001".

dogdoc
05-15-2014, 07:42 AM
Thanks
Most likely too hot mold as bullets look great but frosted. I will increase tin content as well. I guess I need to slow down or operate 3 molds as I tend to want to go fast and am not giving them time to cool down. I read somewhere on this forum about touching to mold to a wet cloth to keep them cool? I know the hazards of h20 in the lead pot so I am hesitant.
dogdoc

gray wolf
05-15-2014, 09:26 AM
Not one of the experts, but, I very much doubt you will get .003 .004 from what you ask.
3 or 4 thou is some serious enlarging from just Temp and a little alloy change.
Then again one never knows.

'74 sharps
05-15-2014, 10:02 AM
Check the LASC site for details on alloy shrinkage.

osteodoc08
05-15-2014, 10:44 AM
Aren't Lyman molds "regulated" for either Lyman #2 or Linotype? If they are casting small with those alloys, it needs to go back for them to fix. Lots of folks have had bad CS from them, however, I recently had a good experience with them correcting and tuning up a mold of mine.

fredj338
05-15-2014, 05:59 PM
Thanks
Most likely too hot mold as bullets look great but frosted. I will increase tin content as well. I guess I need to slow down or operate 3 molds as I tend to want to go fast and am not giving them time to cool down. I read somewhere on this forum about touching to mold to a wet cloth to keep them cool? I know the hazards of h20 in the lead pot so I am hesitant.
dogdoc
I prefer a fan blowing across the mold as I open it, seems to keep temps down enough to keep up a good pace. As noted, you can maybe grow the bullet 0.001" by alloy & casting temp. Beagling or lapping is the better route. I have several molds I have beagled, the only downside is sometimes the foil tape comes off, but easily replaced.

fastfire
05-15-2014, 06:34 PM
I prefer a fan blowing across the mold as I open it, seems to keep temps down enough to keep up a good pace. As noted, you can maybe grow the bullet 0.001" by alloy & casting temp. Beagling or lapping is the better route. I have several molds I have beagled, the only downside is sometimes the foil tape comes off, but easily replaced.

I am hesitant about using a wet towel, today I bought a 4" fan to help cool the mold.
I have a hard time slowing down to the proper rhythm as not to get frosted boolits.
Will usually use more than 1 mold to keep moving.

MrWolf
05-15-2014, 10:15 PM
Add 2% tin to your COWWs. This will give you a proper ternary alloy with a balanced SbSn mixture in the lead for better fill out and an over all better alloy.

Cast with alloy temp at 725 degrees.



Use cast tempo just fast enough so bullets don't frost.

With both bottom pour and ladle fill cavity quickly and leave a good large sprue even if alloy runs off sprue plate.

Your Lyman mould is cut for a ternary #2 alloy not COWWs (your COWWs are tin poor BTW). By doing the above you should get a minimum .429 bullet if not a .430 - .431.

Larry Gibson

Thanks - I have learned early on that you have the ability to explain concepts making it easier for folks like me to understand.

beagle
05-15-2014, 11:48 PM
Don't think you'll get what you want from adding tin. Alloy won't make that much difference from my experiences. Supposedly, Lyman moulds are regulated with #2 alloy but from my experiences, they take a stab at the diameter with CAD machinery and from my experiences, that's hit and miss on Lyman's part. Too bad they don't make trial casts and include the bullet from the mould but I've never seen any evidence of that in my years of casting. You either look for an old Ideal mould as these seem to cast larger, have a machinist to open the bands with a boring bar or "beagle"./beagle