Received and began using Remington 1 1/2 primers in 38 Spl +P loads. I’m getting pierced primers using N340 and AA5 in velocity ranges 960-980 fps with 158 gr cast in my Ruger 4 5/8 inch. I never had pierced primers using Fed 100 or CCI500 at these velocities and above. The 1 1/2 primers are not piercing with Power Pistol and 158 gr bullets at 925 fps +/-. Seems any shot string with an entry of 965 fps and above, there will be some pierced 1 1/2 primers. Again Fed100 and CCI500 work flawlessly without ever any pierced primers.
I seriously doubt my 960-980 fps loads which pierced exceed 25k psi, level Remington says not to go above with their 1 1/2 primers.