N140 might a bit slow. I'm using 45.0 grains of N133, COAL 2.67", Norma brass, Magtech 9 1/2 primer. That will produce 3010 fps at 20 F in my 20" Remington 788. There are some pressure signs already at that temperature. That is about the suggested max load. Start lower. Two 5-shot test groups...