They have some of these ready for the bad guys:

Brass: W-W SUPER 300 WIN MAG headstamp, weighs 241.8 grains specified for one sample.

Primer: Federal 210MGM

Powder: IMR 4350 68.3 grains

COL: 3.335"

Bullet: 200 grain powdered tungsten core, Bubba Bullet. This bullet is similar in length to a 168 grain Sierra match .308 bullet.

These loads are rejected if the primer seating depth is not less than 0.001" from specification. If they meet specs all around, each of these cartridges costs the government over $5.00, and they are buying a lot of them lately.

Do the target and benchrest loaders pay this much attention to primer seating depth?

I just eyeball and feel the primers to see that the are slightly below flush.

What sort of instrument is used to measure primer seating depth? Sumbuddy who know?

The measurement of a primer seating depth on a belted case would be interesting information. Having a small tolerance of +- .001" must be measured from the bottom of the case. Heck the tolerance on just the "headspace" of a belted case is .220"-.227" let alone the real headspace to the shoulder which is -.000" + "infinity"

Since the case will not stop in a chamber with better than .007" total tolerance I don't see a lot of relevance to such a tight seating depth except that overall uniformity is always a goal.

To add: Depth gage micrometers are normal for a tool maker to have and a indicator could do it with a simple fixture.

[ 10-12-2002, 17:39: Message edited by: Don Martin29 ]

All Your Guns Are Belong To Us!!!

Goto www.benchrest.com/sst and look at the reloading supplies section. Sinclair has one, Redding makes another and I think K&M makes one too. For that matter does anyone know K&M's website address?

From sumbuddy who know

Thanks, guys, but I reckon I will just keep lookin' and feelin' the primers and accept donations of any rejected Secret Service ammo.

How much difference would this tiny deviation mean for accuracy

"How much difference would this tiny deviation mean for accuracy?"

Little to none, don't be fooled...

It sounds like the Feds have been tripped up by the minutiae of bumblers yet again ...

Shooting well under 1/2 MOA is fairly easily accomplished with the right rifle, load, and an adequate amount of trigger prowess--with little or no regard for seating depth of primers.

It sounds like the Feds may have consulted the wrong "expert" here, much as they did when the FBI chose the 10mm cartridge for their service pistols ... They've since corrected that mistake, but they went on to make yet another one, again, by consulting the wrong "experts."

The 9mm subsonic 147 grain Hydra-Shok pistol cartridge was initially developed for use in the suppressed submachine guns. Someone apparently thought that would be a good load for Virginia's State Police (after Virginia had ditched the cantankerous 10mm Smith & Wesson service pistols, yes, they had blindly followed the FBI's folly!) to use in their new 9mm pistols. Well, failures to stop perps mounted fast, because the slow 147 grain bullet rarely expanded. Virginia then ditched the 9mm altogether and went with the .357 Sig, a good but unnecessary choice. They should have simply adapted a decent 115 grain 9mm hollow point (not the Silvertip! ) and they'd have been fine.

So the lesson is: Don't let what government is doing impress you as sagacious. It rarely is...

Dan Newberry
green 788

[ 10-13-2002, 17:07: Message edited by: green 788 ]

Green is on the screws. But, following this sort of stuff is an industry now.

They probably didn't know what else to say about primers, but felt that they should have some control specified.

It's still not clear to me that there is much advantage to the 9mm over the 38 Special, other than small size and smooth feeding in an autoloader.

Tom

I think that if you search enough at benchrest.com, you will find that the Feds screwed up on primer depth. The primer should be seated to the bottom of the pocket with the correct force. If that leads to variation in primer deptyh, thta is better than seating them to a fixed primer depth. Obviously, the correct primer depth for any given cartridge depends on primer pocket depth, which is fairly easy for US RELOADERS to make uniform, and primer thickness & anvil dimensions, which I know nothing about.

Of course, you could always produce the ammo correctly, then mike the primer depth and sell the selected stuff for five times what it would otherwise have been worth.