Do I have an undersize mould?

[KirkD]

I purchased a SAECO F7D 881 double cavity mould that is supposed to drop 500 grain, round nose bullets at .460 for my original Springfield Trapdoor 1888. However, the actual bullet diameters are turning out to be .4565". Before I contact them, I wanted to check with you'all to see if it could just be that much shrinkage from the alloy. It was pure lead with just a bit of tin thrown in. I don't know exactly how much tin, because I got it from another fellow, but it produces a fairly soft cast bullet. Is there any way an alloy would shink from .460 when it is just fresh cast to .4565 when it has cooled for a day or two?

[Ben]

Possible that you've got an undersized mold. I bought a 35 cal rifle mold from them a few yrs back, the gas check shank was too small, a Hornady g/c that was crimped on would simply fall off. I called them, they replaced my mold. The 2nd one was fine, no problems.

Ben

[Jon K]

KirkD,

My midway catalog lists Saeco #881 500 gr/.458" *All estimates are #2 alloy. You can figure lead/tin alloy will be .001-.002 smaller, so you are getting the estimated size. You can send it back and tell them you need it to be .460", don't know what they will say, but it's worth a try. You can also have it modified by one of the mould makers, there are several who will modify blocks, or Beagle(do a search on Beagle mould here)

Good Luck,
Jon

[KirkD]

I went back and checked my original order with Buffalo Arms. They advertised the mould they sent me as ".460" 500 Grn. RN Saeco 2-Cav. Gov't Bullet Mould" and the number was SAE65881.

So now I'm wondering if Buffalo Arms sent me the wrong mould. There is no '65881' on my mould, just two numbers ... 'F7D' and '881'. I think I'll email Buffalo Arms and make an inquiry. Even with .002 shrinkage, a .460 mould should give me at least .458". As it is right now, the bullets are undersize for my bore and are wobbling and some are keyholing (and I have an excellent bore that is 10 out of 10 with strong, sharp rifling).

Edit: I went to SAECO's website where they have a write-up about bullet diameter variation depending upon the alloy. They said that if no antimony is used (as in my case), shrinkage will be extreme. My alloy was pure lead with a wee bit of tin. I'll try ww on my next casting run to see if the diameter is a bit bigger.

[Boerrancher]

As Jon K pointed out, most moulds are cut based on Lyman's #2 alloy. That said, there are a few things to look at before sending it back. Casting temp, is the easiest. If your mould and alloy are really, really hot the boolit will drop small, and smaller means lighter. With out knowing your casting temp, I can't tell if that is your problem, but try casting at as low a temp as possible, to get good fill out.

Next is your alloy. Some alloys, just plain shrink more than others do. I know I have to be careful with my 20 lb range scrap to 1 lb WW alloy. It shoots really good out of most of my guns, but it also shrinks a bunch if I get it too hot. A 30 cal boolit that normally drops at 309 with #2 will drop at 305 with my above mentioned alloy if I cast it too hot. With that being said, I can use the same 30 cal mould, straight ww alloy, and moderate temps, and drop 311 boolits with out beagling.

I am assuming that since you are shooting out of an old trapdoor, you would be using a softer alloy. If this is so, watch your heat. If you are casting straight WWs at moderate temps, then it is most certainly your mould causing the boolits to be undersized.

Best Wishes from the Boer Ranch,

Joe

[Boerrancher]

I was in the middle of my post when you posted. I feel pretty good about what I said about the alloys. Sometimes I am not as far off the beaten path as I think I am.


Joe

[KirkD]

Joe, thank you for that info. I'll keep a closer eye on my melt next time around. I do have a Lyman thermometer, but didn't use it, figuring if it was runny enough, I didn't need the thermometer. I should say that that run was my very first experience at casting bullets, so I've got a lot to learn. I'll try to keep the melt temp as low as possible on the next run.

[crowbeaner]

Bear in mind that WWs will cast a heavier but smaller diameter boolit. You'd probably be better with an alloy approximating #2. I use 18# WW and 2# 50/50 bar solder. I've had boolits cast at .411, and they shrink to .409.

[44man]

Not so! WW's will cast a lighter boolit then pure with tin but it will expand as it ages due to the antimony, giving you a larger boolit.
Too much heat with an antimony alloy will cause boolits to shrink more but the proper temperature will give the largest. If you cast too cold, then the mold is not expanded so you get small boolits again.
Pure or pure with tin needs a hotter lead then alloys so 800* is ideal, larger boolits might need more or the mold won't fill out.
I say the mold is just too small, not being figured for BP use but for a modern rifle with hard boolits and smokeless. If it was supposed to be .460 with no. 2 alloy, it sure will not lose that much diameter (.0035") going to soft lead so it is even too small for no. 2 to start with. A .44 or .45 mold will only vary boolits .001" or less no matter what you do with it.
The mold was cut with a worn and re-sharpened cherry. Send it back.

[KirkD]

800 degrees is what I'll aim for then. The mould is actually specially for the Springfield Trapdoor rifle.

[Meatco1]

Some good information here for me as well.

I also have a older Saeco 4 cavity .50 cal mold that is dropping undersized bullets. These are for a.50 cal Hawken, so the bullets are cast with PB. I will drop an ounce of #5 chilled shot into my next batch, and see if the diameter is corrected.

Thank you,

Richard

[Jon K]

Check the Saeco spec for #881
http://www.reddingreloading.com/PDF%20files/tradbullets.pdf