Our model SB is the same bolt and port length as the SV and S but has an integral sleeve that goes over 1 inch of barrel, this is to allow more bedding surface. This action is 7.565” long and has several exterior shape options. Starting weight is 33.5 oz and varies with options chosen. Load port length is 2.30 inches and barrel tenon is 1.062 x 18 tpi. Max barrel is 1.25 inch with max shoulder contact of 1.23 inch.