Measuring Primer Seating Depth with Calipers

[9.3x64]

I have always checked my primer seating depth with a pair of calipers using the depth function on the end of my Mitutoyo calipers. I don’t check every case, just the first few then leave it at that.
However using calipers to do this is extremely inconsistent, unless you have three hands. It can take a lot of mucking around to get repetitive results exactly the same because of the movement.
I just thought I would share a solution I have found in case someone might find it useful.
I ordered two Mitutoyo depth measuring spreaders . They are standard Mitutoyo accessories. They are made of cast iron and extremely heavy and stable. I use a large one at the rear of the calipers, and a small one at the front. I push the large one towards the case slowly, holding the primed case completely firm. The case doesn’t move at all. I have never measured primer seating depth so consistently. I measured three cases five times each, and got the same depth 15 times in a row.
​I have never had this sort of consistency before.
I hope someone finds this useful.

[No1Mk3]

Having a fixture is an aid to consistent measurement for sure, so is experience. As a former machinist constant daily use gets you pretty good after a short time especially if you have a strict Leading Hand bitching at you constantly but for the casual user such a method as you show would be an enormous advantage. Other possibilities include the use of a depth micrometer (can be dear if you buy new or reasonable if you check out auctions) or a DTI. The dial guage is clamped in a fixture with the plunger protruding a pre-set distance from the face then you simply apply each case to touch the face of the fixture and read the dial from your known Zero plus or minus each .0005" (0.013mm) to establish the depth, very quick and very easy one handed measuring.

[Wapiti]

The reloader would be perfectly served with a depth micrometer.
Vernier of any description are just not able to be used consistently enough, although good technique can work well with them as 9.3 alludes to.
But I reckon that not too many are capable of that.

[Fester]

What sort of tolerance or measurement are you blokes going for, a few thou below flush?

Are you finding more consistency for long-range groups?

That's why they use the BR primers but I do OK and have enough consistency for 5-600m.
I would have to re-barrel to shoot F-class groups or shoot longer.

I do like clean as new pockets, and consistent seating feel, just never tried to get mito readings, interesting though.