having issues with rifle casts

M

mwells72774

New member
I never seem to be able to get a good rifle projectile. They always seem to come out with swirls. I've tried colder lead and hotter, varying temp in mold but still get swirls. I can cast pistols just fine. It's 50/50 ww and pure in a Lee pro bottom pour
 
Have you tried pre-heating your mold on a hot plate? And start off with your lead maybe 740° or so and then you can back down if you are getting frost.
If you do heat the mold with a hot plate, the solid top style is preferred. I do use a coil style, but I put a metal plate over the coils. Some say the coil version might warp blocks since it is uneven heat, so I just don't chance it.

Get everything hot enough to frost the bullets and then see if you can't get em dropping nice solid ones and then back down to where it isn't frosting and you should be happy with them!:) Adding 2% tin (or pewter or lead-free solder) will quite often help the lead smooth out in the mold. Tin lowers the surface tension of the alloy and lets it flow easier.

Also.... what size bullet are you trying to cast? Some of the bigger ones (400-500gr) will often do better when ladle-cast. It seems the bottom pours just don't dump enough lead in there fast enough to make a bullet before some of it starts to cool and swirl. Make a big sprue puddle too, at least when starting out. Get that sprue plate good and hot, because if you don't hit that hole perfectly centered with the lead stream it will cool it slightly as it slides across and funnels down into the hole and then might be too cool to spread out evenly by the time it gets to the bottom of the mold blocks. You also might get the alloy extra hot and defeat that tendency, but if you got the big ones, try the ladle once and see if it works. Good luck! :cool:
 
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I guess it was too cold. Heated it to what I thought was too hot and it threw some great projectiles. They do have a slight fin where the mold joint is. Guess I should clean it to be sure?
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If you get it hot enough to cast good ones, then back down to where you don't have frosting or fins, you'll have the perfect spot and you can try to remember those heat settings and the cadence that you used. Glad it's working for ya! :)


Keep an eye on the face of the mold blocks too. When you are casting pretty hot, it is much easier to get specks of lead on the block face or maybe even some tinning where the ends of the lube grooves meet on the mold and that will hold it open just a bit and cause finning as well. If you do gets specks or tinning, just touch a dab of beeswax or really any kind of wax to the spots while the mold is up to casting temperature and rub the spots away with a piece of burlap or denim. It should wipe right off.
 
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To clean oils off a mould, I use an old tooth brush and dish soap and just scrub with hot water and soap. Then rinse and dry. remember to lube the spots that are supposed to be lubed.
 
Mwells, there is a fella over at cast bullets "Lathesmith" who will make you a sizing die and punch for a reasonable fee. I've purchased a couple from him and have been quite content.
 
Heat is not the problem. Sounds like your iron molds core surface is either saturated with storage oil or waxy plate lube. Detergent soap and hot water scrubbing may or may not help. But there is one other sure fire thing you can do to clean them.
 
Buckshot makes great dies, I have a few from him. I also have some from Lathesmith, and I placed a new order for one from him yesterday. Both are very good machinists! :D
 
I was never able to cast pretty bullets with wheel weights, not enough tin in them. You should be able to get some 50/50 bar solder and use that to increase the tin in the mix. I also cast round balls of pure lead, got a lot of rejects as pure lead doesn't cast well either. Come up with some tin and you'll prolly solve the problem.
 
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