240gr. bullets sounds like a .45 cal.

The RB action, seems to me, should work quite safely to about 30,000psi.

100gr. of T7 would be equivalent to about 115gr. 2F GOEX, thus would be a slightly light .45 express-type load.

The generated pressure should be in the lower to mid 20,000psi range. If it shoots well, I would stay with that.

A full express-load of about 115gr. T7 should push pressures to the higher 20,000psi range - about max for the action, in god condition.

A 'modern' Navy Arms (Pedersoli) RB action would be much stronger than an original, although most data for those modern actions is suggested to be held to 30,000psi or less.

In my honest opinion, of course.