Lino casting temp.

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  • Last Post 13 November 2014
mrbill2 posted this 10 December 2011

Want to cast some bullets from linotype. What is the best temp to cast linotype?

I know it's printed in a book sonwhere in all this room of masconfusion, but like most things I can't seem to find it. Help !!

mrbill2

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LWesthoff posted this 10 December 2011

The book says anywhere from 500 F to 600 F. Actually, you can probably go even hotter - you might get some frosting, but a lot of casters like to get even frosting on their bullets.

Wes

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Duane Mellenbruch posted this 10 December 2011

RCBS Cast Bullet Manual #1 suggests pure lead and lead tin mixes be cast at 700 degrees.  WW and linotype are suggested to cast at 775 degrees. 

I tend to run 750 or higher in my Lee 20 pound pot to avoid nozzle freeze up.  I do not mind frosty bullets though.  And I cast mostly for handgun although I use the same alloy and temp for rifle. 

It does not really address wether a ladle or bottom pour pot is used.  Duane

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onondaga posted this 10 December 2011

I have cast with straight Linotype and it casts fine at about 100 degrees above its fluidus point in your pot. It will generally cast well  as long as it is really fluid just like any other alloy or even pure lead. The mold temperature is much more important to control the quality of the cast bullets. Working mold temperature is controlled by casting cadence not pot temperature unless pot temperature way hotter than needed like 750 degrees and up.

Any bullet alloy with lead and tin in it should not be cast over 750 degrees because the tin at that temperature will begin to oxidize very rapidly and the quality of Tin in the alloy to get good fill-out of the mold will be degraded or lost.   Particularly, the Tin on the surface of the flow stream  above 750 degrees will oxidize instantly on exposure to air and that oxidation will act as an impurity or anti-flux and degrade the quality of bullet castings.

I have cast Lino bullets for .223 Rem. for varmint hunting. Lino bullets can be driven to higher velocities with higher pressures than say Lyman #2 but all expansion on impact with game is lost. The Lino bullets either pass through like FMJ bullets or they will violently fragment on hitting bone. A standard factory .22 rim-fire HP will do a better job at killing a woodchuck than a 3000 fps lino bullet out of a .223 Rem at 50 to 100 yards in my experience. Sure, you can hit them out farther with lino bullets, but there will be a lot of wounding and crippling even on woodchucks.

The Lino bullets are great for paper punching,  But,  I can also advise that when casting Lino that if it is water quenched to harden the bullets even more,  that upon shooting the  hardened and now very brittle bullets that the rifling in the barrel will shave the bullets allowing gas jetting and accuracy will be lost and tumbling bullets should be expected.

You can verify the fluidus point of your particular alloy in your pot with a thermometer. Melt a potful of alloy then place the thermometer in the fluid alloy. Turn the heat source off and watch the alloy and thermometer. Precisely when the alloy first begins to change color and begins to get the texture of slush or the surface looks like galvanized steel, note the temperature on the thermometer. That temperature will be within 50 to 100 degrees below full fluidus of your alloy. Casting temperature for your alloy is ideally 100 degrees above full fluidus of your alloy.

That idealized casting temperature of your alloy will work well with a casting cadence of 3 to 4 drops a minute. That speed can be difficult for a beginner but no sweat for an experienced bullet caster.

Gary

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mrbill2 posted this 10 December 2011

Thanks fellows, now it's time to turn on the pot. I'll be using the bullets to punch paper only. Now if I could only learn to punch the hole in the right spot on the paper at 200 yards I'd be a happy camper !! Damn Wind

mrbill2

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RicinYakima posted this 10 December 2011

I agree with ONONDAGA's first two paragraphs, and Wes's books. I start at 650 and turn the temperature down as the mould heats up. That is real temperature, not what the thermostat on the pot says, which is at best a guess within 100 degrees or so.

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LWesthoff posted this 10 December 2011

O.K. I went out to the shop and got my Lyman Casting Thermometer (the shop was already locked up and it was cold last night). Recommended casting ranges for linotype, #2 Alloy, wheelweights and pure lead are noted on the dial. The zones begin at the metal's melting point and go 100 deg. F beyond, according to the “Thermometer Instructions” that came with the thermometer. Lino: 470 to 570. #2: 540 to 640. Pure lead and WW's: 600 to 700.

I have generally worked 50-75 degrees higher than that, and have not experienced any frosting.

As you've probably gathered by now, the best rule (within reason) is whatever works best for you. Your mold (size and metal) and your casting rate have a lot to do with the “right” temp.

Wes

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RicinYakima posted this 11 December 2011

Wes,

Linotype is not capable of frosting if it is of the correct composition. It goes from liquid to solid without a “pasty” phase. This phase is where the antimony crystalizes if there is not enough tin. Most well used linotype, like most of mine, has had a lot the tin oxidized out and has a short pasty phase. It will frost, but I've never been about to prove or dis-prove that it makes a difference on the target.

Ric

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OU812 posted this 13 November 2014

Depending on your mold and casting pace, adjusted pot temps can vary from 650 to 800 degrees to get perfect bullets. My small 314299 iron Lyman mold requires 650-700 degrees. My larger double cavity aluminum 30cal XCB mold requires 750-800 degree pot temp.

Linotype is the best alloy to use in a bottom pour pot because it fills cavity well with less defects. All softer alloys I pressure cast using a ladle.

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R. Dupraz posted this 13 November 2014

Nothing scientific.

Just hot enough to make good bullets

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Pentz posted this 13 November 2014

Get one of Pat's PIDs. Takes the guesswork out of fumbling with a thermometer of uncertain heritage and performance. Cast at a temp that looks good for you, comes with experience depending on temps and lead composition. Most of us shoot lead collected from various sources and that complicates things.

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