I acquired some Boss 12-gauge loads and cut open and dissected five shells from each load. Here are my findings from those dissections.
12 GA 2 3/4" Boss Unmuzzled Bismuth load
1 1/4 oz #4 Bi (192 pellets) @ 1350 fps
PELLET COUNT / WEIGHT (grains) (1 ¼ ounce = 546.9 gr)
195 / 552.9 gr
194 / 553.3 gr
193 / 553.9 gr
190 / 544.2 gr
187 / 541.1 gr
Aver. / 191.8 pellets / 549.08 gr
PELLET SIZE (25 pellets, 5 pellets/shell, #4 pellet dia. = .130”)
.138”, .137”, .137”, .136”, .135”, .135”, .134”, .134”, .133”, .133”, .133”, .133”, .133”, .132”, .131”, .131”, .130”, .128”, .127”, .127”, .127”, .126”, .126”, .126”, .123”
Aver. / .13140” dia.
12 GA 2 3/4" Boss Warchief Bismuth buffered load
1 1/4 oz #4 Bi (169 pellets) @ 1350 fps
PELLET COUNT / WEIGHT (grains) (1 ¼ ounce = 546.9 gr)
170 / 544.1 gr (buffer 19.6)
170 / 539.8 gr (buffer 19.9)
169 / 544.9 gr (buffer 19.8)
168 / 534.9 gr (buffer 19.7)
166 / 530.8 gr (buffer 19.2)
Aver. / 168.6 pellets / 538.9 gr (buffer 19.64)
PELLET SIZE (25 pellets, 5 pellets/shell, #4 pellet dia. = .130”)
.145”, .145”, .143”, .141, .140, .139”, .139”, .138”, .138”, .138”, .137”, .135, .135”, .134”, .134”, .131”, .130”, .130”, .130”, .129”, .128”, .127”, .125”, .123”, .122”
Aver. / .13424” dia.
12 GA 3" Boss Unmuzzled Bismuth load
1 3/8 oz #5 Bi (267 pellets) @ 1350 fps
PELLET COUNT / WEIGHT (grains) (1 3/8 ounce = 601.56 gr)
268 / 610.2 gr
267 / 606.4 gr
267 / 605. 9 gr
266 / 606.3 gr
265 / 605.8 gr
Aver. / 266.6 / 606.92 gr
PELLET SIZE (25 pellets, 5 pellets/shell, #5 pellet dia. = .120”)
.129”, .126”, .125”, .125”, .125”, .125”, .124”, .124”, .123”, .123”, .122”, .121”, .121”, .121”, .120”, .120”, .120”, .119”, .119”, .116”, .116”, .112”, .110”, .109”, .108”
Aver. / .12012” dia.
12 GA 3" Boss Unmuzzled Bismuth duplex load
1 1/2 oz #3 Bi (123 pellets) + #5 Bi (103 pellets) = 226 total pellets @ 1350 fps
PELLET COUNT / WEIGHT (grains) (1 1/2 ounce = 656.3 gr)
232 / 649.6 gr
231 / 655.3 gr
230 / 660.0 gr
220 / 648.8 gr
219 / 645.3 gr
Aver. / 226.4 / 651.8 gr (#3 Bi/123.2 + #5 Bi/103.2 = 226.4 pellets) (#5 Bi/45.58% of payload)
PELLET SIZE (25 pellets, 5 pellets/shell, #3 pellet dia. = .140”)
.144”, .143”, .143”, .142”, .141”, .141”, .140”, .140”, .139”, .138”, .138”, .138”, .137”, .136”, .135”, .135”, .134”, .134”, .133”, .133”, .133”, .133”, .133”, .131”, .129”
Aver. / .13692” dia.
PELLET SIZE (25 pellets, 5 pellets/shell, #5 pellet dia. = .120”)
.128”, .126”, .125”, .124”, .124”, .123”, .123”, .123”, .122”, .122”, .121”, .121”, .121”, .121”, .120”, .120”, .119”, .118”, .118”, .117”, .116”, .116”, .116”, .113”, .112”
Aver. / .12036” dia.