I have had two reports of S&B ammunition generating very hot loads. One was a 303 SMLE, and the other from a Sauer 308.
Does anyone know more?
My experience is with their 9mmP ball from many years back and a variety of shotgun loads that were more recent. Don't have number to hand but the ball was on the hot end of the scale when chronied and the shotgun ammo was subjectively pretty heavy recoiling. I don't have any experience of their rifle stuff but have heard from club members that their .556 is also pretty warm.
They definitely don't go for wimpish loads.
My experience is limited to S&B 9mmP FMJ ammo. These are generally loaded pretty hot, most likely to be viable in those European SMG's that like or need the hotter ammo.