Primer seating depth and primer seating force

[BoydAllen]

Interesting, I’m going to have to try it. I’ve deprimed a number of live primers but it’s never occurred to me to measure a primer afterwards. Thanks for that info.

As an aside, you can seat by feel with the CPS. Also, according to the game you play, changing loads as conditions change at the range throughout a competition may not be an option.

To be clear, I was only using the calipers to hold the primer so that I could examine it with the loupe. This was to determine if the bottoms of the anvil feet were flush after seating. Two were, a third had a tiny bit showing below. The seating force was all that my big old hands could muster with a 21st Century tool. A while back, I measured a few loaded Lapua BR cases that have not had their pockets uniformed. The primers were 205s and if memory serves they were all around .009 deep, and pretty consistent. To repeat myself, I seat by feel. I saw no damage to the pellet, or flattening of the top of the cup.

 

[TylerFromMS]

The seating force was all that my big old hands could muster with a 21st Century tool.

I could see that. And we load 200-400 at a time . That’s why I was referencing the expensive primer.

Thanks again for the ideas. I’ve got some loupes I use for chamber inspection and I think they’ll work great.

 

[mikecr]

I think that there is a lot of merchandising going on.

It's merchandising that leads a notion of feeling instead of measuring,, right?

 

[BoydAllen]

It's merchandising that leads a notion of feeling instead of measuring,, right?
View attachment 1472900

IMO the opposite, since virtually all tools can be used to seat by feel. Similarly there is no profit to be made by suggesting leaving Lapua primer pockets unmolested.

 

[mikecr]

Someone suggested NOT uniforming Lapua pockets?

 

[jimmymac]

Still using the old Lee Autoprime with no issues. This year I decided to stop messing with primer pockets in my Lapua cases. I don't even clean them anymore. I've seen no difference on target. I've had a pretty decent season. KISS YMMV

 

[wildcat3d]

 

[coldboreshot]

 

[mikecr]

When you swap primers, they all go off, but grouping opens & closes with testing.
When you adjust primer crush, which includes pocket depth & primer height, grouping opens & closes.
When you adjust striking, pin fall, diameter or mass, or spring, grouping opens & closes.

You may not notice this at 100yds, but if you're not testing it at distance, you're likely leaving something behind. You could suggest that so & so won once with mud packed under his primers. But that doesn't mean he couldn't have won, or done even better that weekend with more efforts.

I don't believe ignition affects grouping only, but SD as well. Another attribute to watch with testing.

 

[mikecr]

When YOU

 

[Bill Norris]

Still using the old Lee Autoprime with no issues. This year I decided to stop messing with primer pockets in my Lapua cases. I don't even clean them anymore. I've seen no difference on target. I've had a pretty decent season. KISS YMMV

Still using the Lee Bench Primer. I do clean the primer pockets but truthfully I don't think I would see a difference in group size if I did not clean them.

 

[bigbulls]

When you swap primers, they all go off, but grouping opens & closes with testing.
When you adjust primer crush, which includes pocket depth & primer height, grouping opens & closes.
When you adjust striking, pin fall, diameter or mass, or spring, grouping opens & closes.

You may not notice this at 100yds, but if you're not testing it at distance, you're likely leaving something behind. You could suggest that so & so won once with mud packed under his primers. But that doesn't mean he couldn't have won, or done even better that weekend with more efforts.

I don't believe ignition affects grouping only, but SD as well. Another attribute to watch with testing.

Mike do you uniform primer pocket? or clean pockets or both or nothing at all.

 

[BoydAllen]

It's merchandising that leads a notion of feeling instead of measuring,, right?
View attachment 1472900

IMO the opposite.

 

[Retired shooter]

IMO the opposite.

All good information.
We need to buy stock in the Popcorn industry.
To all a good day.

 

[danny]

John Deere is getting into this market with their Hyd primer seater should run around $16.000.00 with genuine JD parts, and you get a hat

You'll only be able to get the primer seater serviced by a John Deere service center that is fully factory certified and has all of the required John Deere diagnostic and repair tools!

Danny

 

[JEFFPPC]

Primer threads are crazier than barrel cleaning thread. Hard to imagine.

 

[wywindsor]

Yep just ask the same type of question. Then proceeded to go down this rabbit hole. Built my own primer seater using a brass dowl inside the case to set the exact depth off the case base. Using a valve spring and a modified valve spring tester and a yokogawa pressure transmitter I made for seating bullet. Weighing and micing 2k primers. uniforming 50 out of 100 6gt cases and any other thing you can think of. 50 primers set by feel with a Frankfort hand primer. the other 50 .001 under case base. I use the case base as this is the only true way to get the exact case base to shoulder/ head space so your firing pin hits the primer the same each time. I shot 4 12 shot groups with one fouler per round. WHAT A WASTE OF TIME. All 12 shot groups were .3 roughly. I don't shoot competitions or am I well know as any type of shooter/reloader. The gun and I have shot 5 shot groups in the 0's. For the most part I'll call this a waste of time. Speedy set me right and I'll call it a day.