Cast .50 muzzleloader bullets coming out too small

[Manzanita]

Cast my first batch of .50 bullets today. Figured as expensive as Powerbelts are, I'd melt down those old weights I saved off some old-timey studio camera pedestals a couple of years ago and try to make some bullets I can shoot for fun without emptying my checking account and maybe even hunt with.

Now, first off, I have very little idea of what I'm doing. Here are the details:

Mold: Lee REAL .50-250 two-cavity bullet mold.

Lead: Came off old studio camera pedestals (counterweights). Don't know the purity. A friend ran his fingernail on a slab and, although it left a scratch, he said they seemed hard. They melt nicely and pour really well as I made a big batch of picture perfect bullets today.

Gun/usual ammo: CVA Wolf .50 (usually with 100gr loose pyrodex pushing a 240gr Powerbelt hollow point. It shoots great but those bullets cost a fortune).

I used bore butter to lube the bullets today. Plan to maybe use something a little less messy but that's all I had on hand.

Here's the problem. The ridges on the bullets are supposed to be engraved by the rifling upon loading; hence the name REAL (Rifling Engraved At Loading). Naturally, you'd expect the bullet to be a little resistant to loading.

Mine practically fall down the barrel. Once they clear the muzzle, they are way easy to push. Today I tried a few out after my casting session and after putting the powder in and loading the bullet, I turned the gun muzzle-down and heard the bullet sliding down the barrel, stopping a few inches shy of the muzzle. I pushed it back, popped in a 209, and fired the first shot with 80 grains loose pyrodex mainly just to foul a barrel a little so the bullet would stay in place. That made the bullets stay put but they still seem awfully loose on the way down to the "fouled" area by the breech. I stuck with the 80 grains and shot at a paper target about 60 yards away. All but the first bullet hit the paper, the rest of them went in the black with a respectable grouping considering I was sitting on a bucket resting the gun atop a rolled up towel on a workmate, but they seem to be keyholing. Not surprising considering how loose they are in the barrel.

My instructions say that using a different alloy than Lee used (I think they said 10% tin/90% lead) can result in a different size and/or weight bullet. Not knowing how impurities affect size/weight or even what's in the stuff I'm melting, I'm wondering what ingredients might affect this and what could someone do to make their bullets come out of the mold a little bigger?

[FrankenMauser]

The purer the lead, the more shrinkage you'll get.
The hotter the alloy, the more shrinkage you'll get.

Harder alloys shrink less.
Colder pours shrink less.

Since you have no idea what the alloy is, I really can't offer any advice there.

But, if you experiment with alloy temperature a bit, you may find sweet spot that gets you a couple more thousandths of an inch.

What size are the bullets actually dropping at?
Do you have a known alloy that you could cast a couple bullets with, to give an idea of whether the mold was cut properly?

[Manzanita]

You already gave me some advice there as I didn't know what factors had what specific effects, so thanks.

A friend did come by yesterday afternoon right after I finished pouring and brought me a big chunk of lead he cut off a sailboat keel. He pours his own bullets and that's what he uses so I'll get to at least experiment with another unknown alloy before hitting up the local tire stores... heh.

I also gave him a handful of the bullets. He was here when I tried loading one in the house (without powder) and saw how loose they were. He uses a more traditional ML and wanted to see how they worked in his.

One of these days I'll buy a nice caliper. I'm using one graduated in 1/32s for reloading and it's not very precise. As for the lead, I may have to buy a known chunk from somewhere just as a control sample.

[Rifleman1776]

Why bullets and not patched pure lead roundballs? Oh, well, you didn't ask that.
Yes, your bullets are too small. Just because a barrel is labeled .50 cal., or whatever, does not mean it is a perfect .50" dia. either lands to lands or groove to groove.
By using a hard lead that loads easily you are setting yourself up for a dangerous situation. As a hunting day warms up metals expand at different rates (lead/steel) and the slick, lubed bullet can slide up/down the bore. Shooting with the bullet half way up/down the bore is a very dangerous situation and your barrel can blow up.
What you need is soft lead and a mould that will give slightly oversized bullets that will engage the rifling and stay put at the bottom of the bore. This can be a time consuming search and an expensive venture buying and trying costly moulds until you find one that will work in your gun.

[m&p45acp10+1]

Preheat the mold before you start casting. Put it on the stove, or a hot plate. I put mine on the gas stove at medium low for at least 15 minutes. I lube the bottom of the sprue plate, and allignment pins with synthetic two cycle oil on a pipe cleaner. If it is not smokin when I put it on the mold is not hot enough.

With a bullet that big it should take at 3 to 5 seconds for the sprue to harden. Turn it upside down after the sprue hardens for about 5 seconds. Then break the sprue, and drop them from the mold.

If all else fails look into paper patching them.

[Boomer58cal]

Mine practically fall down the barrel.

I had the same experience with R.E.A.L. bullets in my .58. I never could get them to work right. They shot pretty good with the 0.005 patch though. Shot through 13 1 gallon milk jugs filled with water.

What brand is your rifle? I know some 58 cal CVA's had a 0.577 bore instead of the more common 0.575. Maybe they're 50 Cal bores are slightly over size as well???

Boomer

[myfriendis410]

You can "Beagle" your mold to add a few thousandths to the diameter. The technique is to add two strips of aluminum duct tape; one on either side of the cavity. Clean the surface before applying and depending on the adhesive it may or may not stay on after it cooks off. Heat the mold 'til the adhesive quits reacting and then cast. Yes, your bullets will be slightly oval, but it apparently make zero difference. Look up the technique on the cast boolits website.

[Manzanita]

I appreciate the input and the ideas. After consulting for a few days with my research associate, Mr. Google, I am of a mind to do one of three things. Paper patches, plain old cloth patches, or teflon (pipe thread) tape.

I'm intrigued by the teflon tape idea. Seems like some have good results with it and others not so good (which seems to be the norm for just about anything online). Wrapped one bullet and it seemed to fit much better. Next time I get a chance I'm going to try it and see how they shoot.

May even pick up some patches and try them.

I also think I've got some of that tape laying around from when we redid our first floor ductwork. Might experiment with that, too.

[Boomer58cal]

I prefer a cloth patches myself. I had bad luck with the tape. Too messy for me. I grew up at black powder rendezvouses and often shoot 30 to 50 rounds consecutively. I got a lot of fouling from the tape in several of my rifles. The tape seem to work fine in my custom made barrels, but I had them made with extra deep riflings( .016 deep)

It wouldn't be a bad idea to try the tape anyway it does work good for some people and in some rifles.

Boomer