I have loaded 20.5 gr of 2400 under a 250 XTP for several years --I have never had an issue with pressure
I have shot close to 5000 rounds over the year and found this this is the most accurate load in my Ruger 45'S

This is a Ruger only type load and I would not shoot it in my 625

I also load a 250 cast bullet over 16.0 gr of 2400 that I shoot in my S&W

I do use CCI 350 primers in the ruger load.

I use winchesrer in the S&W load

I would be careful each gun is different