TargetTalk

OK, all you budding gunsmiths out there.
What is your favourite firing pin shape for .22 rimfire?
Does firing pin shape alter the ignition and have any measurable effect on either velocity or accuracy?
Has anyone done any testing in this area?
What is the ideal strike depth for the pin?

I am not sure that the actual shape has any effect. Size and position of the firing pin strike are much more important.

For any particular gun the firing pin will only hit the case with a certain amount of force. A larger surface area of the firing pin impression will obviously mean that case will not be squashed as much. At the same time however, reducing the firing pin size too much will increase the possibility of the firing pin puncturing the case (bad news).

What I am absolutely convinced about is that the firing pin impression should be positioned just inside the edge of the case. If the firing pin goes all the way to the edge then a lot of the available energy will be wasted in compressing the additional brass in that area.

Now to the big question David, I suspect that you already know all of this so why do you ask?