COAL inconsistency

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barnacle

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Morning,
I’ve been trying to zero in on a good load for my 223 and have found a promising combination. I noticed however, that the cartridge lengths seem to float by approximately 0.03” with my set up.

I think this is enough of a difference to make a difference as I can see the spread of my groups change. To improve consistency, is this a matter of one particular piece of equipment’s slop or does this variation signal a host of poor tolerance combinations?

I’ve been using annealed Winchester neck turned brass. I should shell out for premium brass but I’ve been saving that as I continue to tinker. I realize that my thrifty side may be trying to make a silk purse out of a pigs ear but I’ve the time currently to explore my hobby and see how my efforts impact my rifles performance.

I’m using a Hornady LNL Classic single stage press with a Redding set of dies with a micrometer seater, Hornady ELD-M bullets, a Mitutoyo caliper with a Hornady Bullet comparator with a 223 insert to measure. Since the evaluation of the ammunition is on paper and seems to align with the final length measurements, I’m certain that at least the caliper is reliable and dependable.

To remedy this I suppose I could shell out for better equipment and components. I have also simply tried to seat the bullets taller and then incrementally bump them shorter by making minor adjustments to the micrometer. Is the 30 thousandths variation common with other set ups? Is the consistency a matter of improving all the equipment and components or is there a single change which will assist me?

Thank you for sharing your knowledge.
 
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For starters if you want to get really accurate within your required tolerances, you need to measure every bullet's length before loading , then measure the loaded round at the ogive not the tip.
This should drive you sufficiently bonkers!
You can also test a batch by getting a friend to pick random loaded rounds in lengths of .010 , measure each one and log them for you as you fire them, then log the shot, all without telling you the length of the loaded round .
This will be a real eye opener I'd bet .
Cat
 
Thanks Iron Cat.
The Hornady bullet comparator measures at the ogive but I don’t know enough about that product or the ELDMs I say if one is more consistent than the other. I suppose I should do some measurements of the bullets themselves as you suggest to see how much they vary. The ELDM’s are some of the least expensive bullets so maybe that’s what needs improvement.

I did run the last batch through the press twice with a 90 degrees rotation when seating this last batch to see if that can align the bullet more along the cartridges lengthwise axis and maybe that would change what I’m measuring as 0.01 is a pretty tiny number.

That would be an interesting experiment to have a blind comparison.
 
Probably slight variations in the bullet diameter. I got pulled 30 carbine bullets and because they were crimped before I always get OAL fluxations.
 
puzzling I bet
the seater always presses on the same location on the bullet
and the comparator always measures on the same location of its own, may be different than where the seater pushes
=pointing to the bullets having a variation in ogive shape, enough to give the .030 different reading which is huge
Wonder if Hornady had a mixup
 
I always seat a bit long to where I want to be (CBTO wise). Then make slight adjustments down. This is where the artistry comes in. When you get good at the feel of your press’s stroke, you (I) can seat perfectly every time. My success rate is less than .0005” variance 99 times out of 100.

Caveat: you need a decent set of calipers to get accurate measurements. And I never worry about COAL unless I’m magazine feeding.
 
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I have never measured 0.030" variation in a batch of reloaded shells - you must have something that moves to get that much error - I do not know what variation actually exists on individual bullets - but I was thinking sort of 0.005" or so, at most - has been my thought about possible difference between measuring to ogive on bullet, versus measuring to bullet tip - but I really do not know what the actual number is. You will be able to tell that if you measure individual bullets with the compactor and calliper that you were using. - I would suggest to take each measurement at least a couple times, with the calliper "zero'd" in between measurements.
 
another possibility is your seater is not pushing on the ogive like it should but is pushing on the bullet tip, which may have some variance
still not .030 I would think, Hornady makes pretty good bullets and should have little variation, but something to check
 
As far as measuring bullet overall length (tip-base) I have some Speer TNT's in .224 that vary as much as .025. When I questioned Speer on this they said batch to batch variations are common to keep the weight constant. Mind you these are cheap bullets $23.00/100 but they seem to fly straight enough for 200 yd. coyote hunting.

Bill
 
Only time I had variance like that was with .223 and a compressed load. A lighter charge and my basic Lee press was quite consistent.
 
barnacle said:
I’m using a Hornady LNL Classic single stage press with a Redding set of dies with a micrometer seater, Hornady ELD-M bullets, a Mitutoyo caliper with a Hornady Bullet comparator with a 223 insert to measure.
Click to expand...
A bullet comparator measures seated depth, not COAL.

COAL is the over all length, tip to butt. FWIW COAL is totally useless dimension, except to fit ammo into a magazine.

Do you have more than one shell holder that you use? Shell holders can vary in height. I set up one press for loading match grade 308 and I never change out the shell holder to ensure consistency.
 
barnacle said:
Morning,
I’ve been trying to zero in on a good load for my 223 and have found a promising combination. I noticed however, that the cartridge lengths seem to float by approximately 0.03” with my set up.

I think this is enough of a difference to make a difference as I can see the spread of my groups change. To improve consistency, is this a matter of one particular piece of equipment’s slop or does this variation signal a host of poor tolerance combinations?

I’ve been using annealed Winchester neck turned brass. I should shell out for premium brass but I’ve been saving that as I continue to tinker. I realize that my thrifty side may be trying to make a silk purse out of a pigs ear but I’ve the time currently to explore my hobby and see how my efforts impact my rifles performance.

I’m using a Hornady LNL Classic single stage press with a Redding set of dies with a micrometer seater, Hornady ELD-M bullets, a Mitutoyo caliper with a Hornady Bullet comparator with a 223 insert to measure. Since the evaluation of the ammunition is on paper and seems to align with the final length measurements, I’m certain that at least the caliper is reliable and dependable.

To remedy this I suppose I could shell out for better equipment and components. I have also simply tried to seat the bullets taller and then incrementally bump them shorter by making minor adjustments to the micrometer. Is the 30 thousandths variation common with other set ups? Is the consistency a matter of improving all the equipment and components or is there a single change which will assist me?

Thank you for sharing your knowledge.
Click to expand...

Your seater die pushes on the ogive, not the tip of the bullet. This is good, because OAL for bullets can vary quite a bit.

Did you mean 0.003? because that's normal. 0.03, 3 hundredths, is enought to make a difference on target. Some presses require a cam-over to make consistent ammo. Some dies have different seater stems for different bullet profiles.

Any press using any brand of die can make geed ammo. I suspect something with your process or set up.

Anyway, good luck - hope you can sort it out
 
Thank you all for your replies.
To clarify, I had been using the comparator and measuring on the ogive. Please forgive me for not describing that correctly.

It was after seating and checking the ogive length with the comparator on a set of calipers where the discrepancy was showing up.

Now for the embarrassing part. I’d been working this week while each of you had been adding their insights. I’m grateful for your help. Unfortunately I must have been tired when I loaded last as the lock ring over the LNL die bushings had slipped and was no longer tightly binding the die in place. I’m pretty sure the action of the press caused the die to constantly reposition and I simply didn’t notice. Whoops…
Thank you again for your help. I’ll give the press another go in the next couple days and see if the loads are more consistent.
Thank you for your patience.
 
just for the fun of it I measured 10 cartridges I made in the same session, in freshly annealed brass.
I was aiming for 3.18" while tweaking the the jump into the rifling (secant ogive bullets are finicky about it).
the bullet is "soft point" and this soft lead point is expected to produce above average length variations
or is it?
1725152261786.png
 
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legi0n said:
just for the fun of it I measured 10 cartridges I made in the same session, in freshly annealed brass.
I was aiming for 3.18" while tweaking the the jump into the rifling (secant ogive bullets are finicky about it).
the bullet is "soft point" and this soft lead point is expected to produce above average length variations
or is it?
View attachment 812207
Click to expand...
How are you measuring +/- 0.0001. If it’s a digital calliper it’s probably not that accurate.
 
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