I would start at 23.0g and go up one shot for every .5g loaded...
using a thick primer cup like a 7 1/2 or cci450(br-4).
For instance, load one shot and one shot only looking for pressure signs......
23.0
23.5
24.0
24.5
25.0
25.5
26.
26.5
27.
etc until you determine what is a max load for your gun, accuracy will be within 2.0g of max.
You should get some screaming velocities out of 4198 with the 40's.
using a thick primer cup like a 7 1/2 or cci450(br-4).
For instance, load one shot and one shot only looking for pressure signs......
23.0
23.5
24.0
24.5
25.0
25.5
26.
26.5
27.
etc until you determine what is a max load for your gun, accuracy will be within 2.0g of max.
You should get some screaming velocities out of 4198 with the 40's.