Well, my T3 was spot on with 48.0g of reloader 19(max load) with an overall length of 3.1 inch.My new Sako prefers same load of powder,but likes the bullets seated much deeper;almost to the crimp. 2675fps from 20inch barrels.Choice of primer and case doesn't make much difference in my guns
H4350 gives slightly better velocity at 45.0g
N160 was a real shocker...the T3 was giving 2800fps with just 42.0g but showing serious signs of high pressure.I backed off to 39.0g for more sensible results. It was also pushing 140g bullets at 2750+fps with just 42.0g; accuracy was exceptional at under 40mm @350yards but I was in danger of blowing the gun up! Still managed 2500fps using 38.5g. Needless to say the lower weights are now used for each bullet
I prefer the 129sst over the 129sp but both excellent on Red/Sika/roe
Bottom line is that you should start at the minimum reccommended load and work up untill you find a weight of powder that suits your gun.
Regards