Measuring primer seating depth.

[TommyD11730]

So.... before I hand someone $$$ for a new " latest and greatest " primer seater I had a thought. How exactly do you measure primer seating depth?

Would be nice to know before I condemn my old RCBS bench primer for a "more accurate one".

Thanks!

 

[Kracken McGraw]

Get your brass primer pocket to the depth you want them, and then set them to the bottom with your bench primer.

 

[prone.life]

Precision Primer Gauge

The Precision Primer Gauge takes precision measurements of primer pocket depth and the depth of seated primers in relationship to the face of the case head.

bullettipping.com

i know folks who measure using the depth gauge on their caliper.

 

[jepp2]

I had a thought. How exactly do you measure primer seating depth?

Unless you are uniforming your primer pockets to the same depth, measuring the primer seated depth will not tell you inconsistency in seating. Once you start cutting some primer pockets you will see just how inconsistent they are in many brands. I do find Lapua and Petersen to be very consistent in depth.

 

[Straightshooter1]

So.... before I hand someone $$$ for a new " latest and greatest " primer seater I had a thought. How exactly do you measure primer seating depth?

Would be nice to know before I condemn my old RCBS bench primer for a "more accurate one".

Thanks!

If you've got a good caliper and are somewhat skilled with it, you use the end with the tiny protrusion that comes out at the bottom when you open the caliper to measure depths. It take a little skill to get a consistent measurement.

OR . . . if you want fast and accurate, you can hand over some more $$$ with the Accuracy One tool :

Precision Primer Gauge

The Precision Primer Gauge takes precision measurements of primer pocket depth and the depth of seated primers in relationship to the face of the case head.

bullettipping.com

 

[Oklahoma Jim]

I use a Holland depth gauge.

 

[Kracken McGraw]

Once you start cutting some primer pockets you will see just how inconsistent they are in many brands

I just found that out on some large primer Hornady brass. Used the 21st Century cutter at .127, barley touched corners on some and others moved quite a bit of brass all across the diameter.

 

[anschuter2013]

Who measures primer seat depth? I never knew it could amount to a hill of beans? Maybe the Extreme Long Range guys and gals do?

 

[rlporter507]

OR . . . if you want fast and accurate, you can hand over some more $$$ with the Accuracy One tool :

Precision Primer Gauge

The Precision Primer Gauge takes precision measurements of primer pocket depth and the depth of seated primers in relationship to the face of the case head.

bullettipping.com

this

 

[tmwinds]

In my humble opinion the only seating depth that is important is ensuring that the primer is firmly bottomed out in the primer pocket.
I use a RCBS manual priming tool. I’m sure there are other tools that work just as good. If the primer is not firmly bottomed you could have inconsistent ignition which can kill accuracy.
After a while you will develop a feel for fully seating a primer.
The only measurement I take is running my finger over the case head to verify the primer is not protruding.

 

[Bill Norris]

In my humble opinion the only seating depth that is important is ensuring that the primer is firmly bottomed out in the primer pocket.
I use a RCBS manual priming tool. I’m sure there are other tools that work just as good. If the primer is not firmly bottomed you could have inconsistent ignition which can kill accuracy.
After a while you will develop a feel for fully seating a primer.
The only measurement I take is running my finger over the case head to verify the primer is not protruding.

Me too.

 

[Dos XX]

K & M primer seater with dial indicator. I have one for sale in the classifieds. They measure the pocket depth and the primer height before seating.

 

[marchboom]

tmwinds nailed it. Primers are designed to be seated so they bottom out in the primer pocket. This insures proper ignition. The people making those adjustable primer seating devices are fooling reloaders into thinking that primers have to be seated to a depth different than being seated until they bottom out in the pocket.

Have you ever had a problem with seating primers that way? If not, then why change anything?

Save your money, buy beer instead.

 

[marchboom]

K & M primer seater with dial indicator. I have one for sale in the classifieds. They measure the pocket depth and the primer height before seating.

K&M should be prosecuted for selling a product similar to snake oil. Seating primers doesn't get any more complex than with this device. And what benefits are gained from this tool?

 

[M-61]

The only measurement I take is running my finger over the case head to verify the primer is not protruding.

Yup. I have a piece of plate glass. One of its many uses is to stand a loaded cartridge on it and see if it rocks.
I’m strictly a 100 yard shooter. Why? Unlike many on the site that’s what is readily available to me. 1000 yards? No clue how far I would have to travel. 100 yards? My back yard.

 

[Ccrider]

Some have tested various amounts of primer crush. Worthwhile reading if you have not read the results.

 

[Straightshooter1]

Some have tested various amounts of primer crush. Worthwhile reading if you have not read the results.

Curious . . . based on your reading, what's your conclusion?

Did it lead you to change anything you're doing?

 

[Ccrider]

Yes. I started uniforming primer pockets and try to seat .003+ after crush. There seems to be a range that is more accurate that is not based on depth but on amount of crush.

 

[jackieschmidt]

I think Alex Wheeler mentioned in another thread that he just seated them by feel.

That’s what I do. But then, I shoot Short Range. Those that worship at the alter of ES and SD can probably see a difference in how deep you actually seat the primer.

In my 6PPC, the pockets are generally so loose after 3 or 4 firings that it is really a moot point.

 

[Ccrider]

I think Alex Wheeler mentioned in another thread that he just seated them by feel.

That’s what I do. But then, I shoot Short Range. Those that worship at the alter of ES and SD can probably see a difference in how deep you actually seat the primer.

In my 6PPC, the pockets are generally so loose after 3 or 4 firings that it is really a moot point.

The difference is that you and Alex have loaded tens of thousands rounds and can more easily feel when something is off and, are seating by “feel” to very consistent depths. Those of us with substantially less expedience don’t have the same “feel” for sure. The more I load, the more comfortable I get and the more I seem to notice when a primer touches and crushes.