Small problem: Tearing of bullet base at sprue

[Green_Canoe]

I'm new to casting and had very good luck with my first attempt, casting 425 grain Lyman .50 cal bullet for a .50-70 out of 30-1 lead.

Now I am casting 250 grain .45 bullets in a double cavity Lyman mould out of some scrounged lead. My lead mix was 1 part Lino, 2 parts range reclaim lead, and 3 parts pure lead.

I filled both cavities and left a sprue puddle that was just big enough to connect the two cavities. Once the puddle frosted over I counted to 8 seconds roughly and opened the sprue plate and dumped the bullet.

The problem is when I inspected thebullets later on it looked as if I'd torn the sprue out by the roots rather than getting the nice clean shear I'd gotten with .50 cal. bullets. The bullets look fine otherwise. What can I do to fix this?

[Wayne Smith]

Wait a little longer before cutting the sprue. You may want to switch to using two molds if you are casting that hot that the sprue isn't firm at a count of 8. Pour one mold, put it down, pour the other, put it down, cut and dump the first, etc. Should give enough time for your sprues to harden.

[felix]

When the sprue changes color, from shiny to dull, that's the time to open the plate. ... felix

[Calamity Jake]

Also check the sharpness of the spru hole, that can cause tearing too.

[Trey45]

All good advice above, something that a few of the guys here do is wet an old towell and put the mold on it sprue plate first to harden the puddle faster, I've never tried it myself, but from what I've read here and other places, it gives a nice sharp cut of the sprues with less lead smears and less base tearing. If all else fails, you might want to give it a shot and see if it works for you.

[DLCTEX]

Using Bullplate lube allows me to cut the sprue early without smearing and galling of the mould. I can cut the sprue while still "wet" in appearance, but this is too early as the boolit will be damaged if dumped, but not torn on the base.

[StarMetal]

The old sages here aren't going to buy this, but I and another member cast that way...that is just tearing out the sprue very very little. It has no effect on the accuracy of the bullet. I'm not talking about a deep crater either, but then again when you learn this style you don't get a deep hole. I get my mold up to temperature and do as Felix said, as soon as I see the color of the sprue change I open the sprue plate. I'll never go back to trying to get those flat sprue cuts messing with the size of the hole, the sharpness of the hole, the tightness of the plate itself. .....but there will be many here that tell you the method I'm using is wrong. Tell that to the groups I shoot in many different firearms both long guns and handguns.

[runfiverun]

i do like starmetal does i open with gloved hand.
you develop a nice rythmn that way.
the small scuff is generally flattened out by the stars base punch anyways.

[StarMetal]

i do like starmetal does i open with gloved hand.
you develop a nice rythmn that way.
the small scuff is generally flattened out by the stars base punch anyways.

Thanks for backing me up on this style Lamar.

[Le Loup Solitaire]

I may or may not be an old sage, but waiting for the sprue to change color i.e. from shiney to dull is the way it is supposed to be done, or at least it was for a long time and when I got taught- it was that way. It should not take more than a few seconds for that to happen. If longer, than you are running the temp too high and/or the mold is overheating. This happens especially with larger bullets snd/or when one starts to get in a rush and casting too fast. "Steaming/watercooling your mold" either from the bottom or the top is a way to reduce the heat buildup if it is geting out of hand and the sprues are taking too long to set up, but if you have to do that on every pour.. or every second or third pour then you are running things too hot and/or you are in a great hurry for whatever your reason might be. If however you like that system then by all means be happy. I don't like water anywhaere around a casting/smelting operation. I would choose to use either a small electric fan or use two molds in tandem/alternation to control excess heat buildup. On iron molds getting "steamed" I have seen rust forming...very light it may be, but who needs that or having to clean it off/out of tight places either. As for enlarging the sprue cutter hole or the hole in the dipper snout...that was the subject of an article in one of the NRA bullet casting supplements. The idea was that it made for better fillout. True or not, I personally have always done very well with a dipper and ladle without doing either or both. There was also a trick for supposedly making bases with a minimal sprue mark; that was to pour with the sprue cutter off to one side so that the pour occurred at the very edge of the bullet base. Also there was less to cut. That may have worked for some folks, but I found it bothersome to keep trying to get the sprue cutter adjusted to the same exact spot and getting the stream to pour easily into the smaller opening. Give it a try and see if it works for you. I never had a good notion about things being even a little/tiny bit off-center anyway, especially at longer distance rifle shooting, but anything is possible.. LLS

[Green_Canoe]

Thanks for the replies. I was definately running faster with this mold since it was a pistol bullet to be used at 25 yards rather then a rifle bullet and I was looking for quantity over quality. The more I think about it, the conditions in my garage were much different for my two casting sessions. The first session was in January and the temp was about 35 degrees. This last weekend when I cast the pistol bullets the temp was almost 70. I know I had a lot more heat transfer to the atmosphere in January than I did last weekend. I suppose the bullet mold may have as well.

The tearout wasn't bad, but I'd like to make the best quality bullet I can. You've given me lots of suggestions. I should be able to find something that works for me.

Thanks,

Ian

[BABore]

Like Joe, I run right on the ragged edge of tearing out a bit of sprue. I know everything is running right when I just get a little tearing while running a sharp sprue plate and BP lube on it. I've found that waiting for the perfect, clean cut, shiney text book sprue will actually cause more weight variation. I believe this is from the blocks running too cold and up/down temperature fluctuation. You can weigh some boolits to prove this out to yourself. I now typically only weigh 22 cal booilts and those I want for special accuracy tests. When I first got started I weighed out alot of boolits. Not to segregate for accuracy reasons, but to tweak my casting technique to lower variation. I've found no difference in accuracy with a slightly torn sprue.

[45 2.1]

I've found no difference in accuracy with a slightly torn sprue.

Ha ha ha ha ha............... Now you believe. Now wheres Mikey at.

[BABore]

Ha ha ha ha ha............... Now you believe. Now wheres Mikey at.

More or less. Them ones you sent Mikey looked like HP's on the wrong end.

That said, he did say they shot just fine.

[StarMetal]

Even if they were holes, which I doubt because I have lots and lots and lots of 45 2.1's bullets, the hole is in the center of the bullet axis...wouldn't make much difference. Doubt if it could be measured.

You beginning to believe NEO????? :kidding:

[BABore]

Even if they were holes, which I doubt because I have lots and lots and lots of 45 2.1's bullets, the hole is in the center of the bullet axis...wouldn't make much difference. Doubt if it could be measured.

You beginning to believe NEO????? :kidding:

Un huh!

They kind of reminded me of the throat slug you sent me, but bigger and deeper.:groner::p

[357maximum]

Mikey has been out looking for a job and some shrooms. Not doing so hot on either search.





1. Despite pre-conceived notions on my part ......bases that are torn CONSISTANTLY can and do shoot just dandy. I have actually been doin it that way for awhile now, I just do not make the CRATER as large as Bob does. Compared to shearing the cooler sprue I get the same or better groups, it is far easier to cast every boolit the same, and it is slightly faster. WIN< WIN< WIN

My weight variation has decreased quite a bit since I started doing it THE WRONG WAY.:takinWiz:

*apparently sometimes the grumpy old men here have a clue as to what they are doing even when it is "wrong" to everyone else in the flock*



[smilie=l:That throat slug could have used a bit more thumping......did your arm get tired Joe?[smilie=l: You do need to use a hammer when you POUND a slug ya know.:groner:

[257 Shooter]

Thanks for the laugh Mike. That is an perfect description.

[Marlin Junky]

I wait until I get a color change as Felix suggests but also use Bull Plate lube. Cast with enough heat so about 5 seconds is required to solidify your ample sprue puddle. Before I pre-heat the mold, I will apply a liberal coat of Bull Plate lube to the underside of the spure plate and cook just the spure plate on the hot plate (underside up) until the oil stops smoking. After which, I assemble the mold, attach it to the handles and pre-heat the whole thing. While you're casting all you need is a few swabs with just a trace of Bull Plate on them to lube the block top during the course of a 1-2 hour casting session. Keep the Bull Plate away from the cavities or you'll end up casting a bunch of rejects. I usually ladle cast at between 750F and 800F depending on alloy, etc. and under a couple conditions even a bit hotter.

MJ

[prs]

In working with 250gr .454" 6 cavity Lee molds and WW alloy, I figure its either tear the bases a litle or tear the spru plate a lot.

prs

[44man]

Hard to believe we agree on something! :kidding:
The best shots and casters here ignore the little tear out.
What I hate is when a mold is not right and leaves a little lump on a gas check boolit sprue cut. I prefer a little tear out. Doesn't matter with a PB, sort of like the sprue left on a round ball. Boolit edges are important and I was inspecting some pulled boolits from factory loads when I found something I don't like.
Notice the damage on the base from an off center, too small and crooked base punch on this boolit.