257 Roberts blowed out and necked down to 22 caliber. Winchester plus P brass is Preferred in 257 Roberts. 50 grains of Hodgdon h4831 will easily push an 80 grain Sierra to 3550.
I've had three muzzle brakes installed, to Vais and one by pacnor. The one by pacnor is on my 300 rum it's assisted by a H&S precision stock with the recoil spring resistor in the stock. The other two are on my 375s made by Vais. Actually made by a gentleman named Ron Bartlett out of Texas...
I had the opposite happen ,developed loads in Florida in the eighties temperature wise, hunting in Alabama 26° you might as well been shooting to 308. point of impact changed, velocity fell off the face of the Earth. no more reloader 22.