Failure to fire

[Oso]

Made up a gage this morning as measured to the headspace datum on the cartridge that failed to fire. Found it to be 0.010 inch shorter than several of the remaining unfired cartridges.

Then checked 5 of the cartridges that I fired through the 600. They were very consistent at 0.004 inches longer than than the average of the unfired cartridges.
I believe that the combination of mil primers and a short case was the problem.

I appreciate the suggestions from Texas10 & Coldboreshot you saved me some headaches.
BTW the barrel is a Shaw and was ordered with a match chamber.

This is exactly the issue I had with my rifle... non-spec factory ammo. Go ahead and replace the firing pin spring. Those cartridges that are just barely short of spec will go bang with a better spring... Ask me how I know!!!

 

[Herzo]

I will be working up an accuracy load for this rifle, and just ordered a set of Redding shell holders that will allow me to adjust the cartridge headspace up to 0.010" in increments of 0.002". In that the rifle produced a sub MOA group with the AR ammo, I suspect that it is worth playing with. I am starting with a 53 gr SMK and IMR8208. In that it is a 1:9 twist I suspect that this and heavier bullets will be the best performers.

 

[243winxb]

Herzo. Made up a gage this morning as measured to the headspace datum on the cartridge that failed to fire. Found it to be 0.010 inch shorter than several of the remaining unfired cartridges.

In a Savage Axis 223, the firing pin strike set the shoulder back .006" when a CCI 400 primer didnt fire.

Pin Velocity matters.