Dillon 9mm Seating Die

[mastergunner]

I have a Dillon 650 that I am loading 9mm with a OAL of 1.142 for USPSA. I have noticed that I get a huge variation when seating bullets. They can go from an OAL of 1.130 to 1.165. I am using Xtreme 147gn bullets. Am I doing something working here or are Dillon dies just not that accurate? Thanks for any advice.

[Sarge]

If you do a search for “oal variations” you’ll find tons of info. Much of it sounds like this:

Shell plate as tight as possible

sort brass by headstamp

lube cases

for best results keep the press moving and check random rounds because pulling the handle and checking, pulling the handle and checking does not represent how you really run the press.

 

or words to that effect

[ExStreetWalker]

Make sure you set the OAL with a full shell plate.  Make sure the shell plate is tight.  

[ddc]

For a target OAL of 1.142 I would expect the majority of rounds to be between 1.137 and 1.147.

There would most likely be some outliers but no where near what you are seeing.

There is nothing inherent in the DIllon seating die (or any other seating die) where that sort of variation is expected.