Winchester changed from silver colored primers to brass colored primers around 1999. I called them up at the time. I thought primers were nickel plated, but the guy on the phone said "zinc". Heck if I know. Winchester did tell me that they had gone through a product redesign and made the brass colored primers more sensitive to "offset off center firing pin hits". When I told him that was a bad idea, because more sensitive primers would increase the number of slamfires in semi auto's with free floating firing pins, I became "Persona non Grata" with Winchester Customer Service. Corporations have all the behaviors of psychopaths: they are grandiose, think themselves perfection divine, and the center of the universe. The universe and everything in it is disposable in their interests, plus they lie without shame. Basically, when they mess up, they refuse to admit their failures and shoot the messenger. I believe what Winchester did was compensate for all those firearms out on the market with inadequate ignition systems and worn out mainsprings. What I have seen, shooters with 110 year old mainsprings get all upset when their rusty musket won't light off a cartridge. Then they blame the ammunition manufacturer. Seen a lot of posts similar. Firearms manufacturers constantly design marginal ignition systems. This is in large part due to the loss of expertise in the firearms industry; because of contracting out and cost cutting. Heck, even Eugene Stoner did not know what energy levels were required to consistently ignite rifle primers. His M16 slamfired in service because the kinetic energy of the firing pin was always above the "None Fire" limits of commercial primers. His Stoner 63 Weapon failed to reliably ignite the #41 primer, which had been made in responsive to the heavy firing pin of the M16. So Winchester and all the ammunition manufacturers have an incentive to make their primers as sensitive as possible. If you pierce primers, you replace your firing pin on your dollar. If your gun slamfires out of battery or in battery, its your fault and you cover the costs of whatever happens.
It turns out since 1999, what used to be one of the best primers to use AR15's and Garands is now one of the worst. Federals are the worst because they are the most slamfiring primer on the market, but based on reports, Winchesters are number two. Another issue with more sensitive primers, the old Winchester WSR primer was great, very predictable. But the new brass colored WSR pierced at loads that never bothered the old nickle plated WSR. I ate up a handful of AR15 firing pins, now use them as punches, because the brass WSR primer pierced and dished the firing pin tip. The solution was CCI #41 primers.
Brass colored Winchester primers are fine in my pistols, loaded a bunch of bolt gun ammunition and kept the pressure down. But I am not buying anymore of them in either large rifle or small rifle.
