Use the S365 start powder data for the 150 grainers, and work up from there.
The start load you have from Gordon's is already past the max load for 130 grainers, so rather back off to the start load for 150 grainers from the Somchem data, and work up to what is pressure safe in your rifle.
If 54 grains is the max for 130 grainers, it's going to be beyond the max for a heavier bullet.
I landed on 50.2gr IMR 4350 behind a 140gr Hornady Interlock BTSP for 2850 fps ave out of my Winchester Model 70 Sporter. That provided impressive (for me at least) accuracy with 5 shot 100m groups inside of 20mm.
This was inside of the load parameters from 3 current sources but treat with caution yada yada yada.
Start at the lowest suggested charge and work up from that. Speed will give a very good indication of pressure and then the QL calcs will start to make sense.
What are your rifles dimensions and parameters you are going to use? Quick Load can give an idea of where to start with the IMR4350.
************************ The powder I have is H4350. I have access to quick load, not mine, but I may use it. I found that the loads suggested and max vary hugely, even on sites like Hodgdon, Hornady and so forth.
The powder I have now is H4350. I am starting a friend out in reloading, using Hornady 150gr I/L bullets. I have enough S365 for self, but he has to start somewhere. I see much debate on the net as to max load, listed as from 48 gr right to everyone uses 53+ gr loads.
Batches of S365 are again coming onto dealers shelves. Try and reserve a tin or two from your LGS. The foreign propellants have also become difficult to obtain.
