I loaded these with my Grandfather but I know he has a reputation for liking hot loads. These will be for my Rem 788 in .222 and I don't want loads that blow the primer out like I have had before with his .223 loads.
I`m no help with the 222 but, when loading the 223 I`ve found some regular SR primers are prone to pierce at pressures that don`t show any problems when others are used. The Rem 7 1/2 is a hard cupped primer as is the CCI mil-spec. Federals 205m has shown heavy cratering in 2 rifles, and the Reminton 6 1/2 also appear excessively flattened and often crater with what should be mild/normal loads. My Winchester High Wall shaves a nice clean ring from every single primer with a load of 25gr of Benchmark and a 50 gr ballistic tip when useing Federal 205m. No flattening is evident, go figure...
It has come to the point I use Rem 7 1/2br primers almost exclussively in my 223 any more.
You may want to keep it in mind the next time primers pierce or crater heavily with your 223 loads, and try a different primer.
