Thread: Primers not flush on brass - effect on measuring OAL and jump

Obviously not as quick as a auto primer, but as fast as your fingers can pick the primer up slide it in and not that fiddly a job, if you had big sausage fingers that may slow you down. Once your got the process sorted its easy and they are so smooth to use. Using it you can feel the difference between touching the bottom of the primer pockets and crushed into place.

Originally Posted by Dicko

I don’t think you have any issues to worry about.

In 30 years of shooting I have never had, seen or heard of a proud primer being set of by closing the bolt. Happy to hear from any who have though?

As your cartridge head spaces off the shoulder or belt it will not impact the jump to the lands.

As long as your primer is seater in as far as it will go all is good. While flush is ideal a few slightly proud is no real issue in my option.

Personally I am not keen to try your suggestion.I am so anal about safety I dont even buy factory ammo.

It'll be fine we dont have semi auto's anymore to cause slam fires Thanks Cindy I do feel safer now

Thanks guys that an excellent lot of advice, as you often get on this forum.

No doubt a primer should be slightly recessed below the base of the case and a finger tip can assess this well.

Looking at seating depth measurements, of course a proud primer will add to what you measure ! In the chamber you can have the case touching on the chamber shoulder or maybe a few thou gap. The cartridge headspace (base to shoulder datum) should be about .003“ less than after it was fired which is assumed to be pretty close to you’re chamber headspace length (bolt face to chamber shoulder ) for best brass life but can be more until you start to get misfires. If you have a tight fit then Camming the bolt shut could well seat the primer flush. In practice, the case base to ogive should relate to the distance from bolt face to lands, with whatever your choice of Bullet jump as the difference. Once you’ve reseated all your primers flush or below you can look at setting your jump.