9 MM Lee seat & feed die


July 16, 2013, 12:28 AM
I don't understand when I set up the seating die to 1.125 OAL, it seats the first bullet correctly, but then the next bullets OAL is 1.115 or 1.122 or 1.130 or 1.135. I think you get what I mean. I seem to have the die tight in the turret. What am I doing wrong?
Anyway I reloaded 40 rounds, checking every step of every round, so off to the range later today to see how I did. Thanks

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July 16, 2013, 12:34 AM
Which press are you using?

Are all the bullets the same length? Much of the times when your OAL is all over the place it's because the bullets are slightly different lengths. Which bullets are you using? Give a half dozen or so a measure and see if there is a variation.

July 16, 2013, 02:24 AM
The seating stem in the Lee seating die (and many other brand dies) is dished/concave and don't push on the tip of the bullet but a little down on the nose "ogive" of the bullet nose.

So the consistency of OAL will depend on the bullet ogive consistency. If the bullet nose ogive varies, it will change the bullet seating depth and the OAL.

I get more consistent OAL with Winchester/Montana Gold FMJ bullets than plated RN bullets.

July 16, 2013, 03:29 AM
I sort my 9mm cases by headstamp and still have an OAL spread of at least .01". If you aren't sorting by HS then your spread would likely be higher. Cases with different HS are heaver, or lighter or shorter or longer than others. Which means that the thickness of the case at the mouth will differ, which affects tension on the bullet as it's seated. I've found that if I measure a round to be too long, I can place the round back in the seater and it will come out shorter, even though I left the bullet in. I just don't think you can get that much precision in handgun rounds unless you go to a lot of extra trouble which, at handgun distances, won't make much difference. Unless you're a bullseye shooter.

As long as your OAL is not near the minimum OAL that is safe, i.e., doesn't create high pressures, I wouldn't worry about it for a handgun load. It will just cause the velocity to vary a bit.

July 16, 2013, 07:19 AM
A .005 spread is not unusual. Less is achievable with many pistol bullets, but not all. Any more than that is a poor seater stem fit, poor nose consistency, varying press flex etc.

July 16, 2013, 08:06 AM
Don't over tighten the dies. The O-ring on the die nut should not be compressed, or the force of the press will simply relieve the O-ring compression inconsistently. Instructions are to finger tighten, which doesn't instill a lot of confidence but does work. Just put an alignment mark on the die top.

Don't finesse the insertion stroke. Let the die setting control it once sure of your die alignment and into the stroke.

July 16, 2013, 08:25 AM
Nothing to worry about there. Not enough difference in seating depth to cause any pressure issues. The bullet noses are just slightly irregular (less irregularity than you can see with your eyes) so the seating stem inserts them to microscopically different depths.

It won't make a bit of difference to your group size or your split times, so don't let it bother you.

July 16, 2013, 07:27 PM
Thanks for all the help. I have a Lee 4 hole turret press. For now I am using Long shot powder and Remington round nose bullets. I will try and look into everything that was suggested and get back to all of you. Thanks.

July 18, 2013, 04:44 AM
Bullets, even match grade will have some degree of olgive inconsistency, which is where the seating plug contacts the bullets during seating. Even high quality hunting bullets will have a variance in olgive that is going to be all over the place. the solution, well there really isn't one unless you want to rebuild the bullets to have identical physical properties from olgive to tip, olgive to base, and then matching all of that to precision along with the weights.

I remember way back when I first started reloading being just as frustrated with this. It wasn't until after I talked with a bench rest shoot friend that I felt some relief and assurance that I wasn't doing something wrong, and that my dies weren't the culprit.


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