tollerance for roundballs

[buttonbuck]

I am needing to cast because I am down to the "Plinkers Pile" I will do some more range work. Here it goes. I have a 2 cavity lee mould, they throw different weight balls. I figure I will have 2 groups to shoot from. So when I go back and inspect them and weight them into two piles how close in weight should I go for hunting. I have always done +or- 1 grain When you get this picky you get 1/3-1/2 cull. So the question how much of a tolerance can you have or am I right on with the =or- 1 grain

 

[jtmattison]

I used to weigh mine and cull anything outside of + or - one grain. Then I went to the range and shot a mixed bag of balls that were not weighed. I did not see a difference in my groups. No fliers either. I came to the conclusion that weighing was a waste of time. I am very satisfied with my sub 2 inch, 50 yard groups.

Your results may vary.

HD

 

[Zonie]

I agree with Huntin Dawg.

I don't think hunting requires a ball weight like the target shooters try to use to maintain a 1 inch group at 100 yards.

A LOT of people are very happy using the swaged roundballs from Hornady and Speer for hunting and those vary in weight over +/-5 grains out of the box.

 

[Bill Hall]

I too, got really nutzoid in my younger days, concerning weighing balls. They had to be within +- one grain, or it was back into the pot. Then, for some reason I stopped weighing and didn't notice a difference.

I think it's good to weigh just to find that occasional ball with the occasional air pocket or slag inclusion, especially for your hunting ammo. Just throw out the really light balls, and don't worry about the numbers that are two, or less, grains off. Just my thoughts. Bill

 

[Dphar]

I am needing to cast because I am down to the "Plinkers Pile" I will do some more range work. Here it goes. I have a 2 cavity lee mould, they throw different weight balls. I figure I will have 2 groups to shoot from. So when I go back and inspect them and weight them into two piles how close in weight should I go for hunting. I have always done +or- 1 grain When you get this picky you get 1/3-1/2 cull. So the question how much of a tolerance can you have or am I right on with the =or- 1 grain

You need a better mould and maybe a better lead pot or a better casting technique or all three. I have a Lyman 495 double cavity and when I start casting to keep it will keep about 90% within one grain. I have a 40 that does very well to. My others are single cavity.
I let the pot heat for about 1 hour before I start casting and lay the mould blocks over the pot to heat, just keep it clear of the lead. I then cast maybe 20 balls that I simply drop back in the pot to get the mould hot. When the balls look good and it takes a few seconds for the sprue to set I go into actual production. Leave a big sprue on the sprue plate of the mould it helps produce a uniform ball. Cast at a consistent speed and slow slightly or swing the mould back and forth after the sprue sets if its taking to long for the sprue to set. This will slow the casting speed and let the mould cool slightly. This reduces lead soldering to the mould blocks which can be a problem if the mould is too hot.
I use a Lyman Magdipper pot, run it pretty hot, "8-9" on the dial and I cast a complete run without stopping then weigh these as a lot. If you stop and start when casting or cast some one day and more the next they will not weigh the same and a lot of culls will result. So each session must be a separate lot until weighted then its safe to mix them. Even a 10 minute phone call can change the weight and will require the "new" batch to be kept separate for weighing.

Dan

 

[Dphar]

I agree with Huntin Dawg.

I don't think hunting requires a ball weight like the target shooters try to use to maintain a 1 inch group at 100 yards.

A LOT of people are very happy using the swaged roundballs from Hornady and Speer for hunting and those vary in weight over +/-5 grains out of the box.

But swaged balls do not have casting flaws. Draw down "voids" or air bubbles etc. Cast bullets/balls often do even if "perfect" visually.
In my actual testing of cast bullets I have found that bullets more than 1 gr light will have significant flaws that will effect balance either actual holes or variations in metal density that appear as the bullet is machined away a few thousandths at a time.
While slow twist barrels are less finicky than faster twist bullet barrels I still weight RBs carefully.

I would rather miss a shot in a match than screw up a shot on an animal.

Dan

 

[bwhoffman]

Typically, molds are made, by various makers to throw a certaian grain weight based on a certain lead alloy mix.
ie lyman rifle is like a 20:1
lee roundball is pure lead/no alloy ect.

I found reference at on time regarding Lee rb molds about their tolerences.
(not verbatim here).....the cherries used to make our molds are within the industry specs, which are-.00/+.003.

2 cherries are used to make a double cav mold. most of my lee molds throw different weights in each cavity. my product reflects this!
I use pure soft lead in my .40 and .50 handgun.
everything else is digesting wheel weights....which is an all together puppy mill alloy of god only knows what.

I too have found really no significant difference in my groupings.

FWIW, my free $.02 and your milage may vary!

 

[BrownBear]

I use much the same methods that Dan Phariss describes with great results.... To the point that I quit weighing balls altogether. If I was a match shooter I'd at least weigh my smaller ones, but for calibers over 50 I just can't make small differences in weight show up on paper.

I'll add a couple of insights or precautions to what Dan said. He mentions the large sprue puddle. It needs to be large enough that when you see a little dimple form in the puddle, you're sure that it doesn't drop down below the level of the sprue plate. That dimple going too deep is the source of most voids, especially if your mold is starting to get too hot and is smearing the sprue and closing the top of the void.

Second insight is to go ahead and spend the $20-30 on a Lyman lead thermometer (don't remember the zact price, but TOW has them). You'll really value it for getting consistent lead temps for uniform casting.

Okay, one more. I'm using the bottom pour feature on my pot for all my balls 54 cal and smaller, but with limits. I don't let the pot get down to less than about half full, and I keep the spout good and clean. I could just as well use the dipper for smaller balls like I do the bigger ones, but I'm lazy. Works for me, but variations in pours from the bottom spout can give you some fits if you don't counter them.

 

[ohio ramrod]

If you have variations from the same cavity you probably have small voids in your balls. If your variation is between the holes you have two choices. Make two batches one from each cavity, or just use one cavity. A micrometer will tell you if one cavity is throwing a larger ball than the other. Variations in diameter will effect loading ease, voids can effect accuracy. :idunno:

 

[ohio ramrod]

I have found that I can eliminate voids from pouring with a bottom pour pot by holding the mold against the pour spigot for about twenty seconds after pouring. This keeps the sprue hot and allows it to fill shrinkage as the ball starts to cool. :idunno:

 

[plinker]

I also use the Lee mold. I haven't found that one cavity will consistantly cast larger or smaller than the other. I use the RCBS pot and get around 400 balls in a session. I grab 20 at random and weigh them individually. Then I sort into two groups. The first is within 1/2 grain of the heaviest of the first 20 I weighed. The second group is up to 1/2 grain lighter than the bottom end of the first group. I do all of my shooting offhand and don't really see a difference in the groups, but I do notice a difference in the thickness of the patch I use to get a fit that I can drive home using just hand pressure -- no hammer.

 

[Rifleman1776]

Serious, meaning really anal, target shooters will not use a double cavity mould. When I was like that :redface: I used a Lyman bottom pour pot, Lyman single cavity mould and weighed to within 0.1 grain. Surprisingly, my discard rate was only about 25%.
Today I only do visual inspections but weighing will not hurt. As long as your sprues are cutting off consistently, a one grain variance is a good measure for all kinds of shooting.

 

[rr11]

I have weighed my balls in the past. I shot one target with weighed balls one with swaged balls and one with as cast. At 50 yards all were close. I hunt with swaged but my every day shooting is with cast wheelweights. :surrender:

 

[paulvallandigham]

YOu have to shoot at targets at 100 yds. or further for the voids, differences in diameter, and differences in weight to become apparent in your groups on paper.

For casual, off-hand shooting, don't bother sorting. For shooting at targets at 25 and 50 yards, off=hand, the same advice applies. If you are shooting at 50 yds. off a bench rest, or using cross-sticks, some-not all--- shooters notice larger groups when they don't sort. There are too many other factors affecting group size from a rest to be able to say that all shooters are affected the same. I have, however, watched very experienced match shooters shoot much smaller groups at 50 yds. than I can, using my guns, and my loads.

If you are interested in the very best accuracy, hanging around with top shooters is a great way to learn how its done. And, if you aren't sure if its YOU, or your load combination, ask the Very Best Shooter you know to shoot a group with your loads in your gun. It can be a humbling experience, but at least you will know where to concentrate on improving your skills.


Some of the best advice I have received has been at shooting matches, where some top shooter was kind enough to tell me what he thought I was doing wrong, and what I was doing right. :grin:

 

[Rifleman1776]

I believe voids like air pockets will make a difference at much closer ranges.
Other than that, I pretty much agree with what you say.

 

[paulvallandigham]

Perhaps if you shoot off a rest. Off-hand shooters rarely :thumbsup: can hold tight enough to see the difference.

 

[Rifleman1776]

Perhaps if you shoot off a rest. Off-hand shooters rarely :thumbsup: can hold tight enough to see the difference.

:shake: Reducing any variance will improve scores. A little here, a little there and the medals go to the other guy.

 

[paulvallandigham]

If you read my article on "off-hand and trick shooting", up under the Articles section on the index to this forum, you will understand that I spent considerably time learning to shoot accurately enough off-hand to do trick shot demonstrations for audiences where my local club was hired to appear at some celebration. I was never able to learn to shoot aerial targets, because of safety issues, but I learned to do trick shots at stationary targets. I describe how this is done in the article, disclosing my "secrets" :blah: :surrender: on how I eliminated variables to make these shots in front of audiences. The expectations of both other club members, and the audience puts you under a bit of stress. That is one of the factors you have to learn to control to make those smaller groups. :hatsoff:

 

[CoyoteJoe]

The deer and elk I've killed never seemed to have a tolerance for more than one round ball.

 

[buttonbuck]

Funny thing I found the box of balls I cast earlier. I do have and use a casting thermometer, I think the last 30 or so I cast that were culled from my last session the 1/3 culls were from the mould being too hot. or some manure on the mould face but like you said once you get a pace going you just cast. I think I quit when I noticed a separation line on the balls and then noticed on my last few. I do throw back the first 20, My Pot I let heat about 30 minutes, I use a Lee Pro 20 it has a pour spout but I use the lyman dipper I did not have as much luck with the pour spout, though I am sure it can be done I found myself more content using the ladle.