Hornady LNL OCL problems

[mforsta]

When loading 9mm on my LNL press I am getting a variance in my OCL up to 8 thousands of on inch. It is set to run at 1.169" but I will get anywhere between 1.164 to 1.172. I have cleaned the dies and lubed the cases and still get the variance. The odd thing is it does not do this when loading .45's. I have contacted Hornady and am waiting for a reply. I though I would throw this out to see if anyone has any suggestions for a fix.

 

[angrycookieman]

I'm sure you have, but keep an eye on your shell plate to make sure that it's not loosening up on you. Also, make sure it's not warped. Try one at a time in the same position and check them. You shouldn't be having any issues with consistency.

 

[mforsta]

I can run one round at a time and it'll keep the OCL at the correct length. It only gets out when I load up the plate and run all five stations.

 

[DBMJR1]

Back the die out until it is not crimping at all. Reset your COL. Run some ammo though your press. If the variance goes away, as I suspect it will, you need to separate your seating and crimping into two operations.

 

[angrycookieman]

Try one at a time in different positions on the shell plate and see if they are still the same. Make sure you're not binding anywhere especially the powder measure.
Also, what bullets are you using?

 

[EightySix]

I get .010 variance on my press. What I found is that when I have a case that is a little harder to resize is when I get the most variance. Using a good case lube will help keep the resizing more consistent therefore COL is more consistent. But .008 to me is not a lot to worry about. IMO

 

[Barney88PDC]

I get what you are saying but for pistol does 0.008" really matter? What effect does it have on accuracy and can you shoot the difference? If it affects loading / reliability then that's a different animal. Also bullets differ from bullet to bullet. In rifle ammo even on a single stage press OAL will vary, base to ojive is the important measurement, that stays at +/- 0.001" with my rifle loads.

 

[mforsta]

Am I being a little cautious about the OCL? I reload to mostly shoot paper and steel and not long distances so I don't really notice a accuracy difference. Is .008 acceptable for pistol rounds without getting in to much pressure change?

 

[Barney88PDC]

I would think so. I'm sure the head of the press will float that much. Id shoot them and not look back.

 

[noylj]

You are being too OCD about the COL. It just doesn't matter. Try SHOOTING them and seeing what you get.
Are you shooting at over 100 yards? Are you shooting under 1" at 50 yards?
Have you measured the OAL of your bullets? Have you measured the COL of factory rounds? Has any manual said anything about being concerned with such small deviations for COL?
Pressure change: This all began over a KB with 9x19. One of the companies did tests and reported, in an article, that a round that produced 33-34ksi at standard COL would go up to 60ksi when the bullet was pushed into the case 0.25"--meaning that you should be worrying a lot more about bullet set-back than COL. After seating a bullet, try to push the bullet deeper in the case using finger/thumb pressure and reject any round where the bullet moves.