Will a primer .004 off the bottom of the pockets have different burn characters?

[GSSP]

I ran a primer test a few weeks ago with CCI 250, Fed215M, Rem 9-1/2 and WLRM primers. CCI 250 and WLRM age the best results with accuracy and small SD but the highest ignition failure rate. I really want to use the WLRM primers.

After much thought, fiddling, measuring and testing I found out an answer to my question. Now, it begs another question.

New or 1x fired 338 Edge (Nosler 300 RUM brass necked up) brass.
Primer pockets reamed with Sinclair 8000 Uniforming tool which ended up reaming pockets .134" deep and SAAMI max depth is .132" which resulted in numerous misfires because the firing pin had too much real estate to travel to get the primer to bottom out and provide enough resistance so the primer would fire. This when I use my Sinclair priming tool which gets the primers flush, the primers have as much as .012" of travel before they bottom out.

Discovered if I used my press mounted Forster Coax press priming device, I can get the primers .006" below flush and the primers fire.

Here is my question.

If the primer is approx .004" away from the flash hole do you think it might negate the results of the first test I did vs having the primers flush against the bottom of the pocket? Do you think I should repeat the test; .004" off the bottom vs pressed down against the bottom?

Thanks,

Alan

 

[bigedp51]

Primers are to be seated with a slight primer crush or preload, if the anvil is not touching the bottom of the primer pocket the firing pin blow is reduced as the firing pin finishes seating the primer.

From the Nosler manual below.

As primers are seated to the proper depth, the anvil is pressed slightly deeper into the cup, lightly compressing the primer pellet. This sensitizes or arms the primer so that it will be ignited by the blow of the firing pin. However, primers that are seated too deep are hazardous as the anvil may be pressed into the priming pellet too far making the primer dangerously sensitive. Ideally, primers should be seated approximately .005” below flush with the case head. At this depth, they are sufficiently deep to be safe and sensitized, but are not so deep as to be out of reach of the firing pin.

 

[2506]

If your primer is not seated to the bottom of the primer cup you WILL have misfires. The anvil has to be supported by the bottom of the pocket to allow the compression of the priming compound pellet between the cup and anvil when the cup is struck by the firing pin to ignite. If the primer is not seated to the bottom the firing pin has to knock the primer to the bottom before the primer will fire. When people first started using Wolf primers they complained that the primers were no good because they had misfires sometimes. The problem was that this primers was just a bit larger and had a harder primer cup and people were not getting them seated to the bottom of the primer pocket. I was one of these. Once I found that I had to really put some force into seating them the misfires went away.