How tight do you tolerence your round ball castings?

[LuckyDog]

I just starting casting finally. I started with round ball.

So I have a Lee 490 RB mold. I have what I think is close to pure lead. It was a bunch of chunks that work was getting rid of of. The had been using them to weight things down or apply loads to cables. Some where just chunked out of a larger round disk. Others were cast into cans with eye bolts.

This is my second time casting. I am much happier with last nights results.

I have a PID controller that I put together to control the 10lb Lee bottom poor. (Production Port IV?) I cleaned and smoked the Lee before the first attempt, it spits them out easily.

I cast 244 balls last night and weighed them all this morning.
7 = <173.5gr
64 = 174 +/-0.5gr
120 = 175 +/-0.5gr
36 = 176 +/-0.5gr
17 = >176.5gr

One of the 7 I actually saw a hole in the sprue cut, so I am sure there was a void in there. :cry:

Most measured 2 or 3 thousandths under .490.

Some of the 17 actually measured larger than .490. I think I might have not closed the mold tight enough or loose gripped it.

Had the pot set at 710°F, but sometimes I was casting before it reached temp. Casting at about 680 - 700. Other time I noticed that the pot had overshot to 726°F while I was casting after refilling.

Thoughts?

[William Yanda]

30 degree temp swing with a PID? How long does it take for the PID to learn a smaller deviation from the goal?

[fishhawk]

Just go shoot them and don't worry about that little variation.

[LuckyDog]

Still learning. :)

I had just put all the sprues in and added 2lbs. It was on its way back up. The over shoot id's because i don't have the parameters just right yet. It held the temp great once settled.

[LuckyDog]

Fish, you mean ALL of them? Or throw out the high and low groups?

[fishhawk]

You can throw out the light ones if you want. In theory a pure lead ball for my .58 should weigh 267.5 gr i sort and keep any that are 260 gr or better. If your using loose powder and a measure you got more variation there so don't worry about a couple grain difference in ball weight.

[mooman76]

I keep the ones that look good. Shoot and have fun. Are you shooting competition? If not don't worry about it.

[LuckyDog]

I tossed the lightest ones back in the pot.
The inter-club bp shoot is coming up. I want you my hand cast balls. Now when the patches show up, I'm off to get re sited in.

[Maven]

Variations in RB diameter are to be expected regardless of manufacturer or what the mold is made of (aluminum, brass, "iron"). However, you shouldn't experience much of that with a single cavity mold or even a double during a casting session. You may get more consistency by casting @ 800 deg. F when using pure Pb, at least initially, and by adding a tiny amount of tin to your melt as well. Btw, this ballistic calculator is quite helpful in determining RB diameter & weight:

http://www.beartoothbullets.com/rescources/calculators/php/roundball.htm?v1=.495&v2=2876.1

In short, although I do weigh all my RB and conical castings, mostly to cull the lighter ones (voids?), I'm not convinced it's absolutely necessary.

[LuckyDog]

Maven, are saying a 3gr spread is a bit large?

[Southron]

Round Balls will actually come out of the mould with slightly different diameters depending on the temperature of the metal that flows when it flows into the mould and also the temperature of the mould.

I always recommend weighing your bullets and separating them into different "Lots" of Plus/Minus 1/2 Grain. Of course, the "light" balls go back into the lead pot with the sprues because they have internal voids.

I highly recommend for "Match" shooting you use plastic Quick Charge Tubes. With the Quick Charge Tubes you can WEIGH each powder charge, dump it into the tube and then close the end of the tube with one of your weighed lead balls.

This assures you that you have absolutely the same ball weight and same powder charge for each shot to assure accuracy.

Also, loading with the plastic tubes is much FASTER AND SAFER that using either a powder flask or powder horn to load your rifle at the range. Another "downer" of using a flask or powder horn is IF you have a spark left in your breech and the powder ignites when you dump it into the barrel, then there is a very good chance that the flask or powder horn will be a grenade that will go off in your hand.

Using the plastic tubes, the worst that will probably happen is some singed fingers [of course, always keep the muzzle pointed away from you while reloading.

Another advantage of the plastic tubes is that they can be thrown into the clothes washing machine when they get dirty and be used over and over.

I started shooting muzzleloaders in 1962 and have pretty well learned what is the best and safest way to do things.

Here is the link to the Quick Charge Tubes:

http://winchestersutler.com/ShotLoad.html#QCTube

NOW GO OUT AND HAVE FUN, FUN, FUN WITH YOUR MUZZLELOADER!

[fishhawk]

"then there is a very good chance that the flask or powder horn will be a grenade that will go off in your hand."........ Never never never load directly from a horn or flask into a barrel always use a measure to do any thing else is just asking for trouble.

[LuckyDog]

Those are pretty cool looking.

I've been using 30-06 cases with a 45acp case as a cap.

Thanks for all the inputs.
I'm glad I asked this question here.

[mooman76]

As you continue casting you will get better and more consistent. You might want to separate your first balls you cast until your mould gets up to temp better. If they come out different diameter they will of coarse weigh different. I don't weigh mine but I just shoot for fun. Some people that weigh will separate into groups or separate the best ones from others and shoot the lesser ones when it doesn't matter so much.

[Boogieman]

Maven, are saying a 3gr spread is a bit large?
3 gr. on a 175 gr. ball is 1.7% this is as good as most factory swaged round ball . load them up & shoot them , Your targets will never know.

[Maven]

LuckyDog, Yes, +-3gr. is much too large. Like Southron, I hold my .490" and .495" RB's to +-0.5gr.

[bedbugbilly]

I've been casting and shooting RB for 50+ years - always with soft lead of course. I have never weighed nor put a mic or set of calipers to a ball. They all shot just fine. You can expect some variety in weight and size regardless of mould maker. Trust me . . . today's RB molds are more "precise" than any of the the old "bag molds". You have a decent sprue cutter which cuts the sprue off squarely. A bag mold utilizes a "sprue cutter" (similar to side cutter action). They were used for several hundred years and every RB would have had a different grain weight - but they still shot just fine - in time of war and peace. Quite worrying about it and just go shoot them . . . . they'll all go downrange just fine.

[johnson1942]

i would never use less than a .495 roundball for serious shooting in a 50 cal roundball gun.

[dagger dog]

If you drew a graph of your weights it would start at the lighter weights and curve upwards to the peak weight then curve back down to the heaviest weight, in other words a bell shaped curve, your data is very typical.

The main thing is to keep the overs and unders until you have a good size batch of each, after you shoot up your prime weights then use the lighter or heavier loads adjusting your sights to compensate for the weight difference from your prime weights.

[LuckyDog]

Thanks for all the replies. I'm a mechanical engineer (forgive me 😝) but I do know about / understand / appreciate tolerances. Just trying to keep it practical.

[lobogunleather]

The purpose for which the rifle will be used will tell us more than anything else. If you are seeking gilt-edged accuracy for competition you will benefit from removing every variable (ball diameter and weight, powder charge, etc), and the longer the range the more critical such factors will be. If you are using the rifle for hunting at short to moderate ranges small variations in components will have negligible effect. If you are shooting for casual entertainment relatively large variations may be acceptable.

[white eagle]

Lucky
keep em separated and keep the patch the same shoot and see if they really make a difference
on your target
I have never weighed any of mine but that doesn't by any way shape or form mean I shouldn't
be interested in the results

[fouronesix]

In the past I've weighed and measured a few to check. Couldn't detect much difference among those weighed or measured when I went slow, pitched back the early ones as mold got up to temp, kept a correct pace, had good casting technique, kept the proper alloy temp, payed attention to the sprue cut voids, watched the seams, etc. and used a 1 or 2 cavity mold. Short fat bullets and roundballs are among the easiest to cast for consistency.

For hunting, I owe it to the animal to use the best possible ammo/equipment/judgement- whether it be ML or center fire. For targets or plinking, I don't really owe a paper target or tin can much- whether it be ML or center fire.

[Omnivore]

There are some good comments here. I would just reiterate, saying that your mold temperature is as important as your pot temperature. Other than that; a few thousandths in ball diameter isn't a great big deal. Once you're getting good groups, you can start weighing your lead to see if that allows you to get fantastic groups. There are many other variables to get under control before you go to the extent. I have found that the condition of the bore from shot to shot is as important as anything else, and so you can weight and measure your balls all day and still shoot poor groups. If your getting down to the little inconsistency of the balls being the primary factor limiting your accuracy, you're doing very, very well.