Here's my stab at some data...
Gun: Remington 870 Marine Magnum
Gauge: 12
Barrel Length: 18 inches
Choke: Cylinder (Fixed)
Velocities taken 5 yards from muzzle.
"Anim" link will show an animated .gif of 5, 10 and 15 yard targets. Please don't laugh too loudly at my aim, this was my first time out with a shotgun. And the wind was whipping the targets too.
Mfr: Sellier & Bellot
P/N: ?
Desc: 2¾ in, 4 Buck, 21 pellets
fps: Avg 1128, Min 920, Max 1309, SD 188, N 4
Spread: 5yd/4in, 10yd/10in, 15yd/13in
Anim:
A1
Mfr: Sellier & Bellot
P/N: ?
Desc: 2¾ in, 00 Buck, 12 pellets
fps: Avg 988, Min 969, Max 1018, SD 19, N 5
Spread: 5yd/3in, 10yd/7in, 15yd/11in
Anim:
A2
Mfr: Sellier & Bellot
P/N: ?
Desc: 3 in. Magnum, 00 Buck, 15 pellets
fps: Avg 1081, Min 973, Max 1150, SD 71, N 5
Spread: 5yd/4in, 10yd/7in, 15yd/12in
Anim:
A3
Note: All shots jammed action. Do not use this shell at all.
Mfr: Winchester
P/N: XB1200
Desc: 2¾ in, 00 Buck, 9 pellets
fps: Avg 1207, Min 1161, Max 1248, SD 32, N 5
Spread: 5yd/4in, 10yd/7in, 15yd/14in
Anim:
A4
Mfr: Winchester
P/N: X12XC3B5
Desc: 3 in. Magnum, 00 Buck, 15 pellets
fps: Avg 1071, Min 1042, Max 1114, SD 30, N 5
Spread: 5yd/6in, 10yd/11in, 15yd/15in
Anim:
A5
Mfr: Hornady
P/N: 8627
Desc: 2¾ in, 00 Buck, 8 pellets, "TAP Red Box"
fps: Avg 1484, Min 1429, Max 1574, SD 63, N 4
Spread: 5yd/2in, 10yd/3in, 15yd/8in
Anim:
A6