[BlueStang]

I've had my Dillon 650 for about 6 months now and loaded a few thousand rounds. In my latest loads I've noticed my length has shortened up from 1.135 to 1.127-8 on average. What might be causing this .007-8 change. The dies are tight, any ideas? Or is this a normal change over time to expect and just adjust and deal with it.

 

[bub]

WOW ...... Thought this was a medical problem from the title.

 

[fredj338]

What bullets are you loading? If lead, gunk gets into the seating stem & the rds start shortening up.

 

[CdnInAz]

That's why the seat die has the cotter pin ... easy removal of stem for inspect/clean

 

[JustSomeGuy]

Fred and CdnlnAz have the most probable answer. Such variations are almost always related to a buildup of bullet lube from lead bullets in the seating die. You need not remove the die from the press, but only remove the scissors shaped retainer at the top of the die and the insides will fall out in your hand. You can then remove the crosspin in the center of the die and clean the interior by any means you so choose. I sometimes use a popcycle stick with one end cut on an angle to give it a nice knife like shape and scrape out the goo, but any makeshift tool will do and even a bore brush of appropriate size can be employed.

The only other thing to check for is the shell plate nut... the nut in the middle of the shell plate that holds the thing down. If it gets loose it will allow the shellplate to tip when the sizing operation is being done, and the seating die, being about 180 degrees from it on the shell plate, will tip upwards and shorten the OAL. This is rare, but can happen and so, once the seating die is attended to, you might check the shell plate nut also.