There are a few questions.
Are small primers more accurate than large primers?
Does firing pin strike force variation vary accuracy?
We have the report of Charlie Dell’s test, saying NO. Stevens 44 1/2 rifles, I’m told, have adjustable firing pin force. Testing is simple.
Does primer choice affect accuracy?
My experience and testing says NO, that either the primer sets off the powder charge, or it doesn’t. If the gun fires, accuracy does not vary with primer choice.
My test results for primer choice with cast and jacketed bullets are not satisfactory, other variables are included and/or sample sizes are too small.
A search of the internet found no reports of reasonable tests. There are reports about brisance and primer energy and cup dimensions and anvil location; but the reports that I found connecting primer choice and accuracy have distressingly small sample sizes.
One of the reports counts primer choice in loads recommended by competent shooters. This seems to be a reasonable though fuzzy way to look at the question, so I did.
CBA NM primer choice, by place, (1 = first, 2 = second,&hellip.