SAECO Mold Casting Heavy

[alamogunr]

I just finished powder coating about 200 SAECO #130 .45 ACP boolits. I've had the mold for quite a while but seldom cast with it. Never bothered to weigh either. I'm about to set up to load some .45 ACP rounds for son and grandsons. I have fair supply of PC MP version of H&G 68, 200gr. PC 230 gr round nose and the SAECO #130 supposedly 185 gr. Just to be safe and have these about the same velocity(800-850) I decided to weigh a sample of each.

The 200 gr and the 230 gr weighed in at very close to standard weight. The SAECO #130 weighed 197 gr. That was a lot more than I expected. I checked the scale despite having 2 different bullets come in at close to specified weight. I used my Lyman check weight set that has served me well for many years. It verified the scale was set correctly for each bullet.

I didn't specify the mold for the 230 gr rnd nose bullet because I couldn't remember the number. It was also a SAECO mold. Being fairly new to powder coating, I didn't know what to expect from these PC bullets. Apparently, PC doesn't add much weight. I would have been drastically misled if I had only weighed the #130 bullets.

Has anyone ever encountered this much weight variation from the weight specified for a mold?

[justindad]

I have two copies of the NOE 454-237-RN that weigh 10 grains different. Given that only two molds made in the same year, the variance across all of their molds will be wider.

[243winxb]

My #130 same as yours. Fat & heavy. I used 200 gr data to load. . Your can add linotype to bring the weight down, but thats a waste of linotype.

My most accurate bullet is the Lyman 200 gr bb. But it hard to get .452" diameter, unless i add linotype.

Linotype makes bullets lighter & larger in diameter.

[Kennibear]

When cut with a new cavity cutting cherry (tooling) they are large. The manufacturers want a few sharpenings
on each cherry for cost reasons. I have a Lyman single cavity 358429 Keith 168gr SWC that throws 173gr in wheel weights at 0.360" diameter. I won't get rid of it as it is my most accurate pistol bullet of any caliber. I size it to 0.358" and double chill the bullets then lube in a 0.359" die. I have considered buying a 0.360" G,H&I die to lube to be off the lands for sure.

KB

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[Dusty Bannister]

I have not seen this term before, what do you mean when you "double chill the bullets"? And what is it supposed to do?

[Thin Man]

I have an RCBS mold for the 45-70 cartridge that claims it will cast a 300 grain boolit. Doesn't matter whether I pour straight WW alloy or 50-50 WW and pure lead into this mold, it always drops a 325 grain projectile. I currently own 12 molds weighing 230-545 grains for the 45-70 caliber. In spite of it's weight variance (advertised weight v. delivered weight) this RCBS mold is the tightest grouping mold pattern of all these molds I have. This one will stay with me until my time is over.

[Larry Gibson]

alamogunr

What alloy did you use?

[fredj338]

alamogunr

What alloy did you use?

^^THSI^^ You guys know that bullet wts are set by the mold manf with specific alloys, often Lyman #2.So anything else plus casting temp, will affect final bullet wts.

[243winxb]

⅕https://www.redding-reloading.com/ma...-moulds-charts

Bullet Sizes & Weights – How to Vary Them
The bullet diameters and weights presented in this list are based on the use of Taracorp’s Lawrence Magnum bullet alloy (2% tin, 6% antimony, 1/4% arsenic, 91.75% lead).

[Kennibear]

Chilling is the heat treatment of lead like quenched steel. Chilling means to drop lead into water at a temperature just below melting/solidifying temperature. Chilled shot is dropped from the pour screen into water after falling just far enough for the droplets to turn into spheres by the surface tension of the molten lead. Chilling bullets is usually done by standing the bullets up on a tray in the oven and heating them to just below melting and then dropping them into water. I drop from the mold into water, not a old towel like the Lyman manual used to say how to do it.

KB

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[Dusty Bannister]

I understand the quenching from the mold or oven heat treating and quenching. But the double chilling is the question. Once you heat the item up again, you destroy the original HT/Q and end up repeating the process. Terms can lead to confusion, but the real question is why do it two times when once is sufficient?

[Kennibear]

Because I have measured them and they get harder with the second chilling. They get even harder with three but not enough to warrent it, usually < 1 Bn more. "Chilling" is the correct term for what we do as "quenching" is iron specific. Very hard surface steel objects are often double quenched from two different temperatures. The WW2 Japanese Arisaka bolt action was very low or no alloy carbon steel with an elaborate multi step heat treating that gave it higher strength, surface hardness and ductility than the low alloy bolt actions used by everyone else that had a single quench and temper process. As tested by none other than P.O. Ackley himself.
As counter intuitive as it seems the bullets get harder after two chills.

KB

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[Dusty Bannister]

I guess we should agree to disagree. I have never found any written reference to support the theory that one can increase the lead alloy hardness by repeated heat and quench, UNLESS you change the heating temperature or temperature of the quench water.