Inconsistent OAL on Hornady LNL/Powder Measure problem?

[Kisada]

I've recently started reloading for .40S&W and I'm having a problem with random OAL, using a Hornady LNL. I'm not new to reloading, my 9mm is fairly consistent... but these .40's keep coming out with bigger gap in high/low OAL than I care for.
I went to run a few longer ones through the seating die again with some brass filling the rest of the stations. I took the powder measure off so as not to dump into the primer-less brass and hit about 10-12 in a row with calipers. They all came out to within +/- .002 of my base of lets say 1.125".

I was really surprised at how tight the variance became after the second pass thru the seater.

Any ideas on what I might have gibbered up? I'm running resize, flare, powder, seat, crimp as my 5 stations.

 

[17 squirrel]

I've recently started reloading for .40S&W and I'm having a problem with random OAL, using a Hornady LNL. I'm not new to reloading, my 9mm is fairly consistent... but these .40's keep coming out with bigger gap in high/low OAL than I care for.
I went to run a few longer ones through the seating die again with some brass filling the rest of the stations. I took the powder measure off so as not to dump into the primer-less brass and hit about 10-12 in a row with calipers. They all came out to within +/- .002 of my base of lets say 1.125".

I was really surprised at how tight the variance became after the second pass thru the seater.

Any ideas on what I might have gibbered up? I'm running resize, flare, powder, seat, crimp as my 5 stations.

I believe I would add a little more flare to you cases before seating. It sounds like you are shaving some jacket material off during seating.

 

[Broom_jm]

Consistency is as consistency does, for the most part.

 

[Kisada]

I believe I would add a little more flare to you cases before seating. It sounds like you are shaving some jacket material off during seating.

I will admit, I don't think I'm expanding quite as much as I do on 9mm. But removing the powder measure seemed to alleviate the problem. I also didn't mention, I am not using a ptx of any kind.

 

[looney2ns]

You took the powder measure off?? You mean you took the powder drop off?
Do you have the Powder drop adjusted so that you get a complete down stroke of the handle every time?
You can have the powder drop adjusted too low, and it would stop the ram from coming fully up. Varying case lengths then could cause varying seating depths I would think.
What amount of variances are you getting?

Are the quick change bushings all tweeked down tight with a wrench, you are you just finger tightening. If finger tight, use a wrench.

Then again, I may be all wet.

 

[amboy49]

I've recently started reloading for .40S&W and I'm having a problem with random OAL, using a Hornady LNL. I'm not new to reloading, my 9mm is fairly consistent... but these .40's keep coming out with bigger gap in high/low OAL than I care for.
I went to run a few longer ones through the seating die again with some brass filling the rest of the stations. I took the powder measure off so as not to dump into the primer-less brass and hit about 10-12 in a row with calipers. They all came out to within +/- .002 of my base of lets say 1.125".

I was really surprised at how tight the variance became after the second pass thru the seater.

Any ideas on what I might have gibbered up? I'm running resize, flare, powder, seat, crimp as my 5 stations.

Hope this doesn't sound silly. I also load on a LnL. When first strarting out I had wide variances in OAL. I found the first station (deprime/resize) to be very difficult even though I was using a carbide die. I started using case lube on my 9mm cases and the problem of difficult press and OAL variation went way.

 

[noylj]

It isn't a L-N-L issue, it is a "every progressive" issue.
Be sure the seating and crimp dies are clean. Don't seat and crimp in one step.
Consistent COL is not as important as many make it out to be, but you can't get close to consistent unless the shell plate is full, the strokes are full, the handling of the press is consistent, and the bench is rock solid.
Look at your press. What could you change to fix the COL issue? The only things you could do, besides being consistent, is to make sure there is no flex in the shell plate and it doesn't work loose and the die bushings are down tight (Oh, I suppose you could check that the seating die body and the seating stem are locked down tight also). Other than that, I see no "adjustment" that can be made.
Finally, check the OAL of the bullets and the COL of some factory rounds to get an idea of what normal variation is. Inspect the bullets' meplats and ogives to see if they are consistent. Be amazed the differences in bullets from one swaging die (or cast bullet cavity) from another.
For me, if I can keep variation under 0.01", I'm good to go if just measuring from meplat to case head.

 

[looney2ns]

Stolen from another post:

When you measure cartridge OAL, you do that from the tip of the bullet to the base of the brass (make sure your primers don't protrude and become part of your OAL measurement).
BUT: when you SEAT your bullets, the die does not press against the bullet tip; it presses around the ogive (lower down from the bullet tip). Thus the consistency of the ogive controls the accuracy of bullet seating depth; the COL is not measured from the die contact point of the ogive, it's measured from the tip of the bullet. Thus the bullet shape consistency (i.e., ogive shape consistency) is important to get COL measurement consistent.
I like Berrys, for the price they are most consistent.