The next faster powder i have in stock is H 110 and i am not going there. Too many stories about detonation with heavy bullets. I am not that experienced and i like my hands.

Well documented that 4198 is a bit slow for this caliber and probably at the limit of usable powders with respect to burn rate...

I may just go try and make one up at 13.5 to see if i can even get it to seat. Any general words of wisdom regarding compression?