Looking at the second picture where the OAL is longer it looks like the brass is slightly bulged where the crimp is and it might be just the angle of the picture or the light on the brass. Are you using a roll crimp or a taper crimp? If you are doing a roll crimp not a true roll crimp and you have inconsistent brass length it looks like the die is trying to crimp before the bullet is seated to the depth that you want. If that is the way you are crimping try backing the die up a little so it is not crimping so hard early in the seating process. Or you could try seating maybe 10 or so bullets without any crimp to see if your COL is consistent that way. You do not need much of a crimp just enough to take the flair off of the case mouth. A taper crimp die works well for 9mm. +/- a couple thousands is nothing to worry about on COL
You nailed it!!!!
It's
more than slightly bulged & you can clearly see the bullet's body & base.
This is extremely common with the generic/run of the mill reloading dies. Typical sizing dies size the heck out of the brass, it's nothing to size brass down 7/1000th's+. They want to makes sure they layer proof everything and the end result is gooder neck tension (+/- 5/1000ths) to hold them bullets in.
The issue is when you get a piece of thicker brass that is work hardened/sized too small and use the factory expanders that are just as bad at being not only undersized, they are typically too short and don't expand the brass deep enough. The end result is it takes excessive force to seat the bullet and this causes deflection, bullet deformation, case buckle, etc.
A factory 9mm expander next to a custom expander
Buy 1 of these lyman m-die expanders and it will take case of 90%+ of your oal issues.
Something to think about:
Neo bullet molds make custom expanders that use the lee universal expander die & typically their expander buttons are 4/1000th's under bullet diameter.
Myself the 1st thing I due when getting a new set of 9mm reloading dies is home/polish/open the sizing die 2/1000th's. The 2nd thing I do is toss the factory expander button and make a custom expander that has 2/1000th's neck tension on the thinnest brass I use (remington). Anymore I only use federal/blazer/ww brass, they are pretty consistent (+/ 1/1000th's) and the end result is +/- 3/1000th's neck tension.
There are 2 sides to neck tension & most reloaders want that gooder neck tension to hold the bullet in place. Well that comes at a price, namely it does nothing for accuracy and makes your reloading at the press inconsistent.
These are .358" bullets I load in the 9mm's
No wasp waist, no bulging of the case, no bullet base showing & just for the heck of it a +/- 3/1000th's crimp.
Showed this before, it's not hand/cherry picked by any means. It's nothing more then the test target used that day (green bullet pictured above) to test that load. I still use that load to this day for my short range 25yd or less blammo ammo/dirt clod killers.
Was plating around with that red bullet pictured above for a little while @ the 50yd line. That bullet is a design that came out in 1900 for the 38s&w. It is a hb version of that bullet. I made/tested several different hb pin designs And setted on this hb pin.
The black bull is 1 1/2"'s. The fliers are from 2 things:
Too light of a recoil spring in that 1911 (8#), wouldn't go back into battery consistent/lock up consistently. And some of the bases of the extremely long bullet were getting deformed (8/9bhn) by the web in the bottom of the case.
I've loaded 9mm's for a little while now, back in the 90's we'd fit 6" 9mm bbl's in our 1911 38super race guns and shoot countless 1000's of the lyman 358111 158gr lead rn bullets in them.
At the end of the day you're over sizing your brass too small. Then the expander isn't opening them large enough nor deep enough. The end result is oal's that are all over the place.
FWIW:
I set my 9mm dies up to use .358" cast bullets. If I want to use .355" factory jacketed bullets I use the same setup for sizing the brass, priming, expanding the brass and seating the bullet. I do not taper crimp on the last stage like I normally would with the cast bullets. Instead I use a lee factory crimp die. This sizes the brass down to factory specs and puts the correct amount of neck tension on that .355" bullet.