Yes QC [ quality assurance for you PC types ] rears it's ugly head again.
At one time I had access to an optical comparitor and various microscopes ,it was an interesting time !
Time to go back to double firing pins .One of my old rifles has a rectangular x-section at the tip which goes from outside of the rim and well toward the center of the case head.

Here's a few more of those photos, I thought they were very interesting and saved some.

Some of them look like the priming compound isn't just in the rim, but partway up the inside of the case. I wonder what effect that might have on ignition.

Some interesting cutaway photos.

I did read somewhere that 22RF was reloaded in some parts of Russia when ammo was in short supply by inserting some matchhead paste into the rim of a fired case and letting it dry before adding a bit of black powder and a 22cal lead BB. Obviously they would have had to insert each cartridge into the magazine or chamber so it presented an undented part of the rim for the firing pin to hit.
I guess it would have worked well enough for close range shots.

As to the ignition of 22RF cartridges I have noticed that a miss-fired cartridge, if reinserted into the chamber presenting a new part of the rim to the firing pin and then fired, will in all cases shoot to a different POI often like 2-3" away from the usual POI. I don't know what the answer to this phenomenon is, other than maybe having something to do with a change in case capacity.

Re double firing pins helping ignition, I suspect the reason why many, including myself, find the Gevarm 22 rimfire rifles so reliable and accurate despite firing from an open breach position, is that they have a raised ridge of metal across the breach face which well and truly squashes the rim in two places when slamming into battery.

Here is a 22RF case that has been fired in a Gevarm semi-auto carbine

I shoot old single shot target rifles by preference, either offhand or from the bench, normally at the 25-ring Schuetzen target. My fellow shooters and I test just about every type of ammunition we can get. Misfires happen. When that happens, normal practice is to rotate the case and shoot again. If we get ignition, we usually find the bullet impact to be in the same group (if the ammunition was reasonably accurate in the first place), but not in the same bullet hole. With match chambers, much of that depends on how the bullet is engraved when the round is rechambered.

With 3 types of the old rifles, misfires are not unknown. With the Farrow, it was the design of the firing pin. A new firing pin, redesigned by the gunsmith, solved the problem.

With older Stevens Ideal (Model 44) single trigger actions, mainspring strength and trigger pull are trade-offs. The best trigger pulls come from the weakest mainsprings.

With the Winchester Model 1885 Single Shot, the firing pin strikes the rim at a point where the rim is supported by the spring-loaded automatic ejector. That cushions the firing pin blow. Of the 3 designs, the Winchester is by far the worst offender.

Kewl beans, Waterman. I had forgotten about you schuetzen guys down in dear old Humboldt.

Depending on time & weather, there may be a dozen of us. We're mostly old & time has thinned our ranks. Every Tuesday afternoon is a rimfire match. Schuetzen-by-the-sea. We shoot a lot of rimfires, with some very challenging matches.

All this drifted away from those cutaways, which are good work. Why do some of the cases appear to be tipped at an angle? Camera lens? My monitor?