Inconsistent seating depth

[bgibb42]

I can't figure out what's going on. I'm sitting here trying to load 9mm rounds, mixed headstamp brass with Berry's plated 124 gr. HBFP bullets and using a Lee 9mm seating die. I'm getting very inconsistent depths on just about every bullet. I'm trying to seat to a COL of 1.060", but I'm getting wide swings from 1.042 up to 1.067.

I did load some lead bullets a while back, and while researching my problem, I learned that lube from lead bullets can be deposited on the die, leading to this problem. I cleaned out the inside of the seating cone with some solvent, but I'm still having the same problem. What am I missing?

[Nick_C_S]

I'm getting very inconsistent depths on just about every bullet. What am I missing?

You're measuring too much

Hmm, there is going to be some variance. There just is. I've learned to accept it. Factory ammo has considerable variance. That said, 25-thousandths does seem like a bit more than the usual variance; but even at that, I wouldn't worry about it too much. Make sure everything is snug n tight. (I don't know Lee seating dies at all. I use RCBS dies for seating - and wouldn't consider any other.)

If it were me, I'd back the seater plug out just a little bit - so more measurements are closer to the 1.060 you're looking for, and proceed. Sorry I wasn't able to directly answer your question.

Maybe I'll get scolded for my cavalier attitude. But 30 years of loading, I've just learned to let some stuff go sometimes.

[nemesiss45]

How are you measuring? That does seem a bit high, but you will have variation from bullet shape, seating angle, play in the press, and tension vatiation in brass. I know my .45s can be a pain to sit square in the case, I can only imagine 9mm is worse.
Personally, I only measure 2-3 rounds when loading pistol ammo, then I call it good, run off the batch, then pull 3-5 randomly and plunk test them.

[Brian Pfleuger]

Pull the seating plug out of the die and use it to zero your calipers. Measure a bunch of bullets with it. Whatever variance you get there will be the smallest variance you can get in your finished rounds.

If necessary, find a drill bit as close as possible to the size of your bullet, such as 11/64 for 9mm and drill out the seating plug so it touches the bullet near full caliber size. The bullets will be most consistent at that point.

If you don't see much variance in the bullets, the problem is your technique and/or die setup. Make sure you use a full, consistent stroke every time and the die contacts the ram so it has a positive stop.

[BuckRub]

That does seem like alittle more than usual. Take your seating die completely apart and take a good cleaner for lead and make sure everything is purdy. Next get a bullet and measure. Then measure again. If not the same coal your calipers or ways are messed up. If not continue just make sure you are making full strokes and you don't have alot of play in press and die is tight.
I have a tool, don't no it's name but it sits on a bullet and looks kinda like a big nut with different caliber holes in it. It finds a bullets ogive and use it if you have one and measure a couple different bullets and you'll see if its the bullets or not.

[hartcreek]

You have to remember what it is that you are reloading. Berrys are electroplated cast bullets and they will vary that much easily.

[green_MTman]

you might have to over ajust the seating die just high enough so you know the C.O.L is higher then wanted.
then measure; then keep ajusting down untill you hit desired C.O.L

If your C.O.L varies by less then .005 within the batch that should fine

[MR_X]

What press are you using?

[serf 'rett]

MR_X asks,

What press are you using?

Which was my first thought also. What press are you using?

I've loaded over ten thousand 9mm Berry's bullet in the past three years, of which five thousand were the 124 grain HBFP, and my COAL generally varies +/- 0.001 inches. Loading on RCBS Rock Chunker with RCBS Dies.

I suspect you may be trying to seat and "crimp" in the same step. If so, you may want to try seating and crimping in two separate steps. Back off the die enough so that no crimp is applied. Set your seating stem to get your over all length. The RCBS dies have a lock nut on the seating stem, which makes very fine adjustments difficult. I generally get the seating stem set slightly high and then lock the stem in place. I make the final fine adjustments by leaving the die lock nut slightly loose, screwing the die in the press and then locking the die in place.

I like to use a cross bolt die lock ring instead of the O ring on the Lee dies.