Primer Seating Depth?

Jimmy · Apr 11, 2005

Forster states in it's catalogue that the primer should be seated at a depth of .004" from flush of the case head.I am squareing the primer pocket with a Sinclare primer pocket uniformer(set at the shalowest cut).Using my Sinclare primer seating tool,my primers are at a seated depth of from .006" to .010".I can feel the primer bottoming in the pocket and then just a slight nudge with the tool.I have had no problems with this method.It is just that after reading the Forsters .004",I am wondering if I am doing something wrong?
Please advise!
Jimmy : :?

rick smith · Apr 11, 2005

If they all go off when the firing pin falls, you don't have a problem. Primers need to be just below flush with the case. RCBS makes a tool for measuring, go no go type tool. What are you using to measure the distance? The end of a standard caliper is not accurate enough for that type of measurement. Unless you are into some very serious bench rest shooting, you are spinning your wheels with that type of measurement. You will not be able to see any difference with standard or most custom built rifles as far as group size.Rick.

Jimmy · Apr 11, 2005

Rick,I am using the back of the calipers to measure the depth.Yes,I know this is not an accurate way to measure,but it might be in the ball park.This is a custom .300 Win mag.I just want to do every step of the reloading process to as near perfection as I can!If I throw a shot I want to be assured that it is not the fault of the round-but me!The rifle shoots less than 1/2" when I am on my game!I have a RCBS catalogue and can't locate the tool you mentioned.Do you know what it is called?
Thank you,
Jimmy

Seedsntrees · Apr 13, 2005

RCBS made a GO - NO Go gauge for primer seating depth. I use it if I change something to verify the correct depth. Works pretty well and I think it has .004 as the correct depth.

Regards

rick smith · Apr 13, 2005

Jimmy, don't worry about the seating depth of the primers as long as they are below flush. That will not make enough difference in the group for you to see. That may be something for the bench rest crowd. Seating depth will cause seeable differences. As will other things but seating depth of the primers is not going to help you. My last group with my 300WM measured in the 2s and I seated my primers with an RCBS bench tool. I don't remember what they called the tool or if it is still offered. I have had mine for many years.Rick.