Re-visiting weighing RB

[kopelli]

Without getting too far into the weeds, I'd like to get your ideas on weighing round balls.

The question is not "IF" to weigh round balls, but if you do (or have experimented with) weighing round balls,

1) How did you do it and what tolerances/variables do you use?
and
2) How did you measure the difference in results (consistency in groups or accuracy)?

I've read both Steve Sells and Dutch Schoultz, and several comments on various forums, and have purchased scales and started weighing 50 Cal. round balls. I've become confused, and, would like to hear some specifics from those of you that are into weighing.

For example, on weighing:

1) Do you find the greatest weight of individual ball and discard any that deviate from that weight by some variable?
2) Do you find the average weight and discard any ball that deviates by some factor (say .5 grains or .25 grains)?

For example, on the measurement of increased efficiency/accuracy:

1) Did or does weighing reduce you group size by inches? at yardage? Caliber?

By way of further explanation, I am trying to develop a load for my 50 cal TC 1:48 and I believe to achieve the best (tighest) groups I need to control all the variables I can, one of which is the weight of the RB. But at what cost? Out of a box of 100 Hornady RB's, there are 12 different weight groups of balls (by .1 gram increments) from 177.6 down to 176.5. So where to start testing? Therefore, my question to you, is what method and tolerances do you use to achieve the groups you desire?

If, I can/could reduce my groups from 2" at 50 yards, to cloverleafs at 50 yards, I would no doubt weight. However, If I get from 2" down to 1.5 inches, probably not worth my time. I've seen some excellent videos of near ragged holes and clover leafs at 50 and 60 yards and if weighing gets me closer to that, I'll like to try it!

 

[William Sublette]

Shoot more, think less.

Your worrying about the color of the dining room before you've even poured the foundation.


Your biggest variable is the loose nut behind the butt plate. Until you control that, the rest is meaningless.

 

[TreeMan]

When I pour roundballs if they don’t have wrinkles or any blatant defects they go in the box to shoot. I’ve never had an issue with fliers that I would attribute to a ball that weighed and grain or two more or less. Bore conditions such as inconsistent fouling shot to shot will effect accuracy more than weight of the balls. Now if pouring minies I’ll do a better inspection and weigh those because being so large they’re more apt to have air pockets and blems.

 

[dkasprzak]

Out of a box of 100 Hornady RB's, there are 12 different weight groups of balls (by .1 gram increments) from 177.6 down to 176.5. So where to start testing?

@kopelli I too shoot Hornady RBs in my TC Hawken .50 1-48 twist and weigh all balls when I initially purchase a box. Using your example above I would keep everything that is within 1 gram, IE 177.6 to 176.6 OR 176.5 to 177.5 and save the ones outside the group for plinking. With the numbers you provided, I would keep the “heaviest 1 grain group” as you are trying to eliminate “flyers”.

Not sure if this will help you get the group sizes you want but… at least you eliminate one variable. And just to confuse matters, if you can’t shoot clover leafs at 25 yards stay there until you can, then move to 50 yards. Have fun tinkering.

 

[dkasprzak]

@kopelli I meant to add these to the initial post above. This is after weighing balls, finding the right thickness patch and using TOTW Mink oil.

 

[Grenadier1758]

The sorting should be based on the weight of a pure lead round ball. For a 0.490" round ball, the weight of a pure lead round ball is 176.9 grains. And 176.9 grains should be the desired center point of @kopelli's sorting distribution. Keep the balls from 177.4 to 176.4 grains. There won't be much difference in accuracy on target with balls from 177.9 grains to 176.0 grains. Once the balls are sorted by weight, determine which group most of the balls are gathered. For that box of balls, select the balls +/- 0.5 grains. But for purposes of load development keep the balls from +/- 0.5 grains for initial load development. Once the tightest group loading combination has been determined, then try loads using the +/- 1.0 grains. The real differences will start to show up at 50 yards and be more obvious at 100 yards. At 50 and 100 yards the consistency of the shooter in grains of powder, sight picture and trigger release come into prominence.

Sorting by weight is more of a benefit for cast round balls to try to identify those balls with casting voids thtq form as the lead cools and may draw in some lead and air through the sprue if the mold is not quite completely full.

 

[pat i.]

I think wind and sight picture would play a much bigger role in group size than a 1 grain weight difference in the balls.

 

[hanshi]

Over my 56+ year career of shooting round ball I've had lots of tiny groups, one hole, cloverleaf at 50 yards. I've always cast for every caliber I own and never weigh them. If they look okay that's good enough for me. IMHO I consider weighing round ball a waste of time.

 

[Ozark Mtn Muzzleloader]

Over my 56+ year career of shooting round ball I've had lots of tiny groups, one hole, cloverleaf at 50 yards. I've always cast for every caliber I own and never weigh them. If they look okay that's good enough for me. IMHO I consider weighing round ball a waste of time.

I agree. I also think the same thing about measuring black powder or substitutes by weight. I usually hear the old standby response of “bbbbbut they do it at Friendship & win”. I question if anyone there ever tried it a different way…but I digress.

 

[Tenmile]

A double cavity mold will usually throw slightly different weights. If we do the physics we see that this has only a small effect on velocity. Remember Newton’s Second Law
F = ma
If the force F (powder) is constant and we have balls with masses m1 and m2, then we have
F = m1a1 and F = m2a2
This gives
(m1 / m2)a1 = a2
Hence the accelerations (and therefore the velocities) vary by the ratio of the masses. If there is only a small difference in mass, this will have a small effect on the trajectory.
The important reason for weighing is to cull any light balls that might have a cavity. This will have a profound effect on the trajectory.
If this sounds pedantic remember that this was known and understood long before flintlocks were invented.

 

[pilot]

The difference in weight by one grain is .35%. Do you also weigh your powder charges to the same tolerance?

Personally I don't weigh either of them. My shooting skill is far more of a factor. Weight differences that small are meaningless.

 

[SciAggie]

@Tenmile Great explanation. I'm not sure why this is debated so often. Consistency matters in all aspects of the load for best accuracy. I'm like some of y'all - if I'm piddling along shooting for chuckles and grins then I don't weigh my RB. If I get an occasional miss so be it. But for my main hunting load, I want the best accuracy I can achieve. I often load my rifle and it may stay loaded for a while. If I'm shooting a game animal I want high confidence in my gun/load combination.

So here's a test I did with my .72 English Sporting rifle. The only variable below is the RB - everything else was the same. All targets are 5 shots at 50 yards.

This target was with swaged round balls I purchased - not weighed.

This target was with hand cast bullets - not weighed.

This target is hand cast bullets weighed within +/- .5 grain.

That's enough to convince me that weighing the balls is worthwhile for this rifle at least.
I'll add that I have a target that I shot with a Remington Hepburn in 40-65 (lead bullets and BP). One day I put 20 consecutive shots from the bench inside one MOA at 200 meters. THese bullets were hand cast by me and weighed within .1 grain of each other.
Does weight matter? Yes.
Is it worth YOUR time to weigh and sort bullets? You decide.

 

[SciAggie]

To the OP: the swaged Hornady RB will most likely be inconsistent in weight. If you really want to get the best accuracy, then you might consider buying a quality RB mold and casting your own bullets. That's another step, but most of us enjoy it. I think you will find you can really improve the quality and consistency of your projectiles by casting your own. I would bet that many of these folks that never weigh their bullets - cast their own and cull them quite hard visually. They may not be weighing them, but they are certainly "sorting" them by some criteria.

 

[Tenmile]

I usually weigh them because it’s something I enjoy doing. At my age I don’t get in a hurry about much. For target shooting I like to remove as many variables as possible. I’m the biggest variable. Powder poured in a measure is not perfectly consistent. Wind, light, many things influence shooting. That’s what makes it enjoyable.

 

[Maven]

1) How did you do it and what tolerances/variables do you use?
and
2) How did you measure the difference in results (consistency in groups or accuracy)? ...kopelli


I use my electronic powder scale to weigh RB's as it's much faster than my conventional scale (RCBS 5-0-5). Why do this at all? Mostly to eliminate another variable when shooting. Curiously, I no longer do this with the bullets I cast for my CF guns.

What I do is use a calculator with a statistics program to find the arithmetic mean of a sample of say 15- 20 RB's Using the calculator, I find the standard deviation for small samples to figure out how much variation to allow for the rest of the RB's. Btw, I'll store and label them in a Twining's Tea can so that I don't have to spend as much time weighing the next batch.

Is it worth it/does it make a difference? I really don't know, but, as I said initially, it does eliminate an additional variable.

 

[longcruise]

Also realize that a ."490" or ".535" mold isn't necessarily going to drop a ball that size. I have a .530 mold that drops at .533. Also any variations in your lead content will result in weight  And diameter variations. Mix a little wheel weight with the lead and the balls will be bigger and lighter. I know, that's very counterintuitive!

One of the Corbin brothers advised that the most difficult projectile to swage consistently is the round ball. That probably explains the often noticed fact that carefully cast balls are more consistent than store bought from "Big Bullet".

 

[kopelli]

Over my 56+ year career of shooting round ball I've had lots of tiny groups, one hole, cloverleaf at 50 yards. I've always cast for every caliber I own and never weigh them. If they look okay that's good enough for me. IMHO I consider weighing round ball a waste of time.

Appreciate the comments and won't argue with your success. But since I do not cast my own, would you then think weighing might be advantageous? If you did not cast and control your own , would you test others for weight consistency?

 

[kopelli]

1) How did you do it and what tolerances/variables do you use?
and
2) How did you measure the difference in results (consistency in groups or accuracy)? ...kopelli


I use my electronic powder scale to weigh RB's as it's much faster than my conventional scale (RCBS 5-0-5). Why do this at all? Mostly to eliminate another variable when shooting. Curiously, I no longer do this with the bullets I cast for my CF guns.

What I do is use a calculator with a statistics program to find the arithmetic mean of a sample of say 15- 20 RB's Using the calculator, I find the standard deviation for small samples to figure out how much variation to allow for the rest of the RB's. Btw, I'll store and label them in a Twining's Tea can so that I don't have to spend as much time weighing the next batch.

Is it worth it/does it make a difference? I really don't know, but, as I said initially, it does eliminate an additional variable.

 

[kopelli]

Here is the distribution of rb from one box of Hornaday. I set aside 4 or five outside 177.3 and 176.5 range. I just plan to Track what I shoot and see if I can tell a difference. Looking forward to getting back to the range.

 

[kopelli]

Here is the distribution of rb from one box of Hornaday. I set aside 4 or five outside 177.3 and 176.5 range. I just plan to Track what I shoot and see if I can tell a difference. Looking forward to getting back to the range. View attachment 165084

weights are difficult to see: 177.3, 177.2, 177.1, 177.0, 176.9, 176.8, 176.7, 176.6, 176.5.