Primer Crush

[Liberty's Teeth]

Hey Meke,

Do you have data on appropriate primer "Crush" dimensions for the various popular rifle primers? I know my .004" depth setting for free float pins and want to preset my KN cutters to get a correct primer crush. Any help would be appreciated.

[WARFAB]

Primer crush is just seating depth, or something different?

[Liberty's Teeth]

When a primer is installed it is "activated" by by compression. I'm trying to find out how much compression is correct. So let's set the scene; I use a KN cutter to cut my pockets. Using the case head as my datum I can set the cutter face to machine the depth of the pocket. Using the same datum, when I install primers I want to be able to measure the
crush or activation thickness off the top surface of the primer. I may be over thinking this but I'm asking if this can improve consistently from shot to shot with the precision rifles

[Meketrefe]

Hi,
I think .001 should be perfect for federal primers.
After you uniform the pockets and flash holes then sit the primers flush, give it 1/8th extra turn or so and that should land you close to the .001 depth.
Even 2 thou is perfect. The main thing is that they are consistent and you do not crash them. I use the lapua pockets as templates for everything since
they are super consistent. The feel here is very important.
I don't go crazy with these things as flash hole uniformity as well as neck tension/crimp are a lot more important factors in keeping the spreads in the single digits.
People write huge articles about different methods that is ok but also I question the usefulness.
Good brass, consistent brass spreads, consistent pockets, consistent flash holes, consistent seating those are relatively simple directives.

edit: never compress the anvils!