Primer Seating Depth

[thestoicmarcusaurelius]

I recently watched

and

The conclusion seamed to be that seating primers 9 thousandths below flush was close to optimal

Which tools does the group here think are capable of seating primers consistently to 9 thousandths below flush consistently with a reasonable margin of error?

What's an acceptable way of measuring how far below flush the primer is seated? Could this be accomplished with the depth gauge on quality calipers or would different equipment be needed for this measurement?

 

[DngBat7]

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

Super Precision Click Head Bench Rest Priming Tool (Priming Tool and shell holders: Super Precision Priming Tool with #1 Shell Holder)

All our products are made in the United States.

21stcenturyinnovation.com

 

[Pres100]

Just watched those as well ...
Wasn't he trying to say that the optimal condition was .009" of Anvil compression - not primer .009" below flush?

I could be wrong, but that's what I got.

 

[thestoicmarcusaurelius]

He very well could have been. I watched them when they were released and was going off memory. I’ll go back and watch again.

 

[Chaotik]

There is an interesting recent thread with 136 posts that I believe deals with some of these issues here:
https://forum.accurateshooter.com/threads/primer-seating-depth-and-primer-seating-force.4052190/

 

[Pres100]

Primal rights is selling a tool to supposedly control, but have not tried it

PR CPS

 

[newbieshooter]

Just watched those as well ...
Wasn't he trying to say that the optimal condition was .009" of Anvil compression - not primer .009" below flush?

I could be wrong, but that's what I got.

wasn't he saying that .009" below flush actually resulted in .009 anvil compression?

This pic showed BR4 with anvil height of .013. Seated .009 below flush resulted in .009 compression - leaving .004 of the anvil between the primer cup and the bottom of the primer pocket.

His pic has 450's with anvil height of .009. Seated .009 below flush resulted in .009 compression leaving no portion of the anvil remaining between the primer cup and the bottom of the primer pocket.



I could have it all wrong - but that's my initial take of this pic...

 

[Pres100]

Suppose it depends on the primer pocket depth and primer used, but if you used either of those "depths below flush" or specific primers in case that didn't have the same .122" pocket depth, the primer compression wouldn't be the same.

I'm just trying to understand this as well. We'll have to wait for the experts I suppose.

 

[newbieshooter]

Suppose it depends on the primer pocket depth and primer used, but if you used either of those "depths below flush" or specific primers in case that didn't have the same .122" pocket depth, the primer compression wouldn't be the same.

I'm just trying to understand this as well. We'll have to wait for the experts I suppose.

I think in the video he measured the primer pocket depth to be .122 (thus the .122 in his drawing). if you measure a different depth for your primer pockets - then make the appropriate adjustment to maintain the same amount of crush based on the primer you are seating?

 

[Pres100]

That was my understanding ... 9k primer compression seemed to be the ticket... although he did say that you should test! The concept of some consistency in seating and anvil compression makes sense ...

Happy New Year.

 

[JEFFPPC]

It's New Years Eve, not sure if you guys started early or need to get started.....drinking.

 

[jackieschmidt]

I use a hand priming tool. I seat it all the way, then rotate the case 180 and hit it again.

I suppose most of this becomes a moot point when the primer pockets get so loose that there is no feel what so ever when the thing goes in. Common occurrence in the 6PPC.

 

[thestoicmarcusaurelius]

Starting to watch the video again and it mentions that Saami spec is up
To 8 thousandths below the face of the case head

 

[Ray123]

I recently watched

and

The conclusion seamed to be that seating primers 9 thousandths below flush was close to optimal

Which tools does the group here think are capable of seating primers consistently to 9 thousandths below flush consistently with a reasonable margin of error?

What's an acceptable way of measuring how far below flush the primer is seated? Could this be accomplished with the depth gauge on quality calipers or would different equipment be needed for this measurement?

The sample size is too small to draw any real conclusions, there was no real difference in velocity or SD except one a little bit in this test which would have some influence on accuracy but no it did not..so sccuracy would be a random event...like if the exact bullets that were accurate were loaded with the non accurate seating depth would the difference been reversed....then there is primer control issue...would the same 5 primers act different at .009 or flush...there is no way to tell...Can't make the same exact primer with the exact amount of mixture and cup to anvil placement, and distance betweem exactly the same...nope. As, No two primers are exactly the same. So I draw no conclusions... except it works, if you believe that it does... like most of this stuff.

 

[thestoicmarcusaurelius]

He does say that anvil compression is the key variable but then seems to use saami spec interchangeably which would be 8 thousandths below flush measured from the case head and to try to stay in the .007 to .009 range.

 

[thestoicmarcusaurelius]

It almost seems like “distance below flush” and “anvil compression” are being used interchangeably in the videos

 

[WyleWD]

I recently watched

and

The conclusion seamed to be that seating primers 9 thousandths below flush was close to optimal

Which tools does the group here think are capable of seating primers consistently to 9 thousandths below flush consistently with a reasonable margin of error?

What's an acceptable way of measuring how far below flush the primer is seated? Could this be accomplished with the depth gauge on quality calipers or would different equipment be needed for this measurement?

Did I miss where they use a Primer Pocket uniformer at any point in these or your testing? WD

Edit: added the word miss

 

[lawrence97]

The witch doctor video also mentions him using a volume powder dropper (clicks instead of weight) which is what short range BR uses. I think a proper test is using powder weighed to .02 gns on a good scale. This will show a true reflection of any ES or SD changes based on primer seating depth. Just dropping powder by volume/clicks already has a ton of built in ES and SD.

 

[WSnyder]

Did I they use a Primer Pocket uniformer at any point in these or your testing? WD

He did not (at least that's what I recall). He touches on the dimensions of the pockets in I think the first the video and the uniformity was good. There are many that don't touch Lapua PPC pockets or flash holes and do quite well.

He does say that anvil compression is the key variable but then seems to use saami spec interchangeably which would be 8 thousandths below flush measured from the case head and to try to stay in the .007 to .009 range.

It almost seems like “distance below flush” and “anvil compression” are being used interchangeably in the videos

I don't believe he really does, if it seems that way it's because with the dimensions of his brass and primers it just lines up that way. I also believe he's suggesting that a SAAMI max spec of .008" below flush might be good if you do nothing else.

 

[Pres100]

He does say that anvil compression is the key variable but then seems to use saami spec interchangeably which would be 8 thousandths below flush measured from the case head and to try to stay in the .007 to .009 range.

Likely because he was discussing a single caliber and referring to the SAAMI spec for that caliber .... I think we may be thinking interchangeably (or universally) ... at least I have been. That's where the testing comes in.

It seems the anvil compression is what the control is targeting, but the measure of compression is the math of how far the primer is seated (for given primer) vs the pocket depth.