.243 Winchester Brass. CCI 250 Mag primers.
The Speer book discusses how the primer depth below the head should be between .003 and .005 inches. With brand new brass many primers seated anywhere from .001 to .0045 inches.

1. How critical is this depth, understanding issues of firing pin actions, headspacing, etc?

2. The new brass primer pocket depths were not consistent - many were shallow which accounted for <.003" depths. What tool can be used to properly shape/drill the primer pocket to attain a proper seating depth.

I ask because I'm not comfortable using the pocket brush to "grind" away enough brass to make the primer seat to the required depth range.

Thanks in advance.

If a tool is what you desire my new friend look up sinclair International they have a dandy carbide tool that you can mount in a cheap cordless screwdriver and they work well.

Welcome to A R

Cliff,

I'll start off by assuming that you've researched primers and know that magnum primers can be used for the .243 Win, but that non-magnum primers such as CCI 200 or Rem 9 1/2 would be a more common choice.

1) It is critical that the primer not be sticking above the level of the brass, but the consistent exact depth within a thousandth of an inch is most important only if you are a high-level precision shooter.

2) It is normal for primer pockets of Winchester or Remington brass to be not exactly consistant. Buy yourself a primer pocket uniformer, such as the one Lyman makes. They are simple and quick to use. Save the brush to clean up the soot and not to grind away brass.

Good luck

I've just bought the Lyman hand tool; seems to work fine.

Good counsel from all - thanks. I just ordered a uniformer for my .243 and my .223 and will dress-up the remaining brass accordingly - thanks.

Also - I'm using a magnum primer based on a recommendation the Sierra tech folks made for the bullet I'm using: No. 1535 90gr FMJ BT with 36.4gr Reloader 15 for approx 2800 fps.

Clif,

IMO

I think you’re worrying about some very small things here, and it’s not necessary.

Duckboat is giving you some good advice.

quote:

Originally posted by Clif Maloney:
Also - I'm using a magnum primer based on a recommendation the Sierra tech folks made for the bullet I'm using: No. 1535 90gr FMJ BT with 36.4gr Reloader 15 for approx 2800 fps.

Ok,,,,,,,,,,,,,

Cliff, I'm with Mick. Uniforming primer pockets is a chicken soup thing IMO. If it makes you feel better then go for it but I've tried it and am satisfied it's just another one of those anal things folks do to waste time. As long as the primer is below the surface of the head of the cartridge, it's good to go. I am not a high level Bench Rest shooter but I do hold my own in the factory matches.

The only time I have had issues with high primers causing misfires has been with my 458 Lott. Firing pin was scooting the primer forward on first shot, 2nd shot, bang.

Clif; I think it is admirable that you are interested in all these accuracy tricks, BUT you have got to be one heck of shot and have one hell of a rifle to notice any accuracy difference on target, and that rifle doesn't have a magazine and shoot hunting bullets. Load some ammo and go shooting, have fun, you can worry about all these little things qwhen your too old to shoot.