Chasing COL

[BruinGuy]

Newbie to reloading here.

Everything I'm reloading, I seem to be doing a lot of "chasing C.O.L." (or OAL if that's the preferred acronym).

I'm using Lee dies, according to the instructions, on a Lee single stage press.

I loaded up 80 rounds of 30-06. I trimmed all of the brass to the same length, and was getting variations up to nearly .050 with Hornady 150gr FMJBT (manual says 3.185 is COL). It wasn't a consistent issue, either - some were over, some under. I started backing the seating plug out and slowly doing each round, screwing it down a little at a time, in order to get the correct COL. This took FOREVER.

Last night, I loaded up 80 .223 rounds, 40 of each of two different bullets (Hornady .224 55gr SP w/cannelure and SP SX). Although the variation I was getting wasn't as drastic, only about 50% hit my target of 2.200 OAL (per the manual). A small number were over (2.202-2.208) with many being under, some coming in as low as 2.175! When I'd try to adjust the seating plug after seeing one come in under by .02 or so, the next round would be way over and I'd have to screw it back down to get back to 2.200. The SP SX (no cannelure) were more of a problem.

I know these variations are for the most part minor, and I don't think they are going to affect function, but what the heck? Why can't I get a consistent COL? My brass is perfectly trimmed to identical lengths, I'm checking them all with a case gauge, I'm meticulous with my powder charge, and I'm following the instructions to the letter for the seating die.

Is this just one of those things you learn to live with, especially when making up any quantity of ammo? Could it be variations in the brass, especially different manufacturers or lots - and if so, why, if the brass is all uniformly trimmed?

[Germz]

New to reloading? I can promise that a BIG BIG part of attaining a very consistent overall length (especially with lesser quality presses) is developing a consistent stroke.
Maybe overkill, but I practiced my down stroke on my press with my eyes closed so i could get a specific "feel" for it. I back my seating dies all the way out so that when my downstroke of the press encounters the tiniest of resistance, the seating is done. and I only use the web of my palm to push the handle down ever so gently. I have also practiced it to the point that I know if I give it a little extra "oomph" it will seat .007-.008 deeper. Practice as it is a important trait to posses (knowing how much pressure to apply to your press that is).

Try it, guarantee you will see results. I can do 100 rounds of 9mm on my dinky lee press and hit 1.150" about 95% of the time.

[nubrun]

Look at the meplat (tip of the bullet). I bet you will notice that they are not "square" and may be contributing to your COAL measurement issues. That is why it is recommended to measure to the ogive, although I know that it difficult when load data is presented with COAL.

[ocabj]

Look at the meplat (tip of the bullet). I bet you will notice that they are not "square" and may be contributing to your COAL measurement issues. That is why it is recommended to measure to the ogive, although I know that it difficult when load data is presented with COAL.

This is correct.

COL from base to tip/meplat is important to ensure it's below magazine length.

While you might measure 100 rounds you just seated and find the COL varies, if you measured base to ogive, you're going to find that those same 100 rounds don't vary much at all.

[emptybottle151]

I got over it. Although my 9mm is more consistent than my .223 don't really know why.

[metalliman545]

pulling the lever too heavily, that's what I noticed stopped mine from doing that, and if youre using different brands of cases

[ocabj]

I got over it. Although my 9mm is more consistent than my .223 don't really know why.

The seating die's stem makes contact with the tip of the bullet with 9mm, whereas the seating die's stem makes contact with the ogive of the bullet with .223.

[BruinGuy]

Measuring base to ogive, from what I'm reading, requires additional tools and sounds like it's mostly done by those seeking super-accurate loads. If it can generally be assumed that the bullets are seated correctly given minor variations in COL, that's okay with me for now. I'll have to let my OCD perfectionist tendencies go for a little while.

I'm definitely going to try to be more consistent with my lever pulls. I did notice that when I started to partially seat the bullet, and then completed seating on a second pull, they were more consistent. I'll work on it and see if I can't get better results - at least closer without constantly fiddling with the seating stem.

Thanks for all the input so far everyone!

Follow up question though: I know that what will be safe to fire, either over or under OAL, is largely dependent on the individual firearm, but for a beginner, what would be the point over or under what the manual says for COL where you would pull the bullet and try again? Is there a number? Five hundredths? A full tenth? Or does it depend on too many other factors?

[mark501w]

I set the cartridge up for the individual gun ,fit in the mag & functioning in the gun.

[nubrun]

Follow up question though: I know that what will be safe to fire, either over or under OAL, is largely dependent on the individual firearm, but for a beginner, what would be the point over or under what the manual says for COL where you would pull the bullet and try again? Is there a number? Five hundredths? A full tenth? Or does it depend on too many other factors?

It depends... What is your freebore... how close to max are you... What color socks are you wearing...

Ok I was kidding with that last one, but it really depends on a lot of things.

[Germz]

yea. seating depth affects pressure for instance.

[sr71brd]

Measuring base to ogive, from what I'm reading, requires additional tools and sounds like it's mostly done by those seeking super-accurate loads. If it can generally be assumed that the bullets are seated correctly given minor variations in COL, that's okay with me for now. I'll have to let my OCD perfectionist tendencies go for a little while.

I'm definitely going to try to be more consistent with my lever pulls. I did notice that when I started to partially seat the bullet, and then completed seating on a second pull, they were more consistent. I'll work on it and see if I can't get better results - at least closer without constantly fiddling with the seating stem.

Thanks for all the input so far everyone!

Follow up question though: I know that what will be safe to fire, either over or under OAL, is largely dependent on the individual firearm, but for a beginner, what would be the point over or under what the manual says for COL where you would pull the bullet and try again? Is there a number? Five hundredths? A full tenth? Or does it depend on too many other factors?

Hornady makes a reasonably priced bullet comparator that attaches to the blade of your caliper. It allows you to measure your bullets from base to ogive. You'll find some manufactures can have bullets that vary from as little as .001" from bullet to bullet to as much as .040" in the same lot, the higher end being bullets bought in bulk. I have measured some Mil surplus bullets higher than that. If all I'm doing is plinking, I don't stress too much about measuring. But if I'm after accuracy, I will divide bullets into groups of no more than .005" variation per group. That seems to help, all other things being equal. If I can see, without measuring, that my cartridges are different lengths, I pull them & measure.
As far as seating, try starting a bullet, turning the case a third, seat a little more, turn another third & finish seat. It's easy on a single stage press, not so much on a progressive.

[Enfield47]

I had some variation like that in my .223 reloads. Turns out it is the bulk bullets that have the variations. Some bullets are a little heavier than others, some measure a little longer but they all worked fine.

I use the Lee classic cast turret press and I'm still learning the feel for it. I guess it will all come along in time.

[sixgunner]

Its all good

Go buy some reloads or check whatever factory ammo you may have, you will notice they are all over the map. Just for fun I pulled some gun show reloads and the powder varied up to 1 gr or more for 223.

[NiMiK]

You need to measure off the ogive. I had the same problem a couple weeks ago with some SMK's. COAL is a safe number that will allow you to load them in a mag but measuring off the ogive will give you more consistent seating. Here's a link that may help you.

https://www.youtube.com/watch?v=phQdxDwe804