I wanted to tell you the results I got today with my 14" Not-A-Shotgun 12 gauge Mossberg with the Shockwave Grip. This was a modification I made on a pistol-grip-only model 500.
The choke was fixed cylinder. I fired only one each of the three kinds of double-ought shells I had ready to hand at a measured 10 yards from the muzzle. Each shell was fired at a clean target.
General rule of thumb is that from a cylinder bore shotgun, shot will spread roughly one inch per yard distant from the muzzle. That general rule was greatly at odds with what I found.
My 14 inch barrel gave the following extreme distances between pellets at 10 yards distance. All shots were fired using the strap on the fore end and raising the pistol grip to eye level, sighting with the bead. Most patterns were higher than I thought I was pointing.
A center chest strike would have resulted from a hold between belly button and sternum on an average American male.
Three shots from cylinder bore:
1. Eley Alphamax 2 3/4 inch 00 Buck, 12 pellets. 5 3/4 inch diameter, nicely rounded. Centered six to seven inches higher than I aimed.
2. Spartan 2 3/4 inch 00 Buck, 9 pellets. 6 1/2 inch diameter evenly spread in a rough 4 inch circle except for the stray which opened up the pattern.
3. Winchester low recoil 2 3/4 inch 00 buck, 8 pellets. Rounded pattern 8 1/8 inch extreme diameter in a rough circle.
If future tests confirm today’s results, I plan to buy more of the Alphamax for this gun. I like the increased number of pellets. I was focused on the targets and did not notice any difference in recoil between the different shells. IMO, the difference in pattern size here between the Eley and Spartan was negligible.
I moved on to my Mossberg 590 Class III, also with a 14" barrel, bead sight and grip strap on the pump. Believe I captured all pellets but two on paper. Because this barrel accommodates screw-in chokes, I shot each shell with each of three screw-ins. Same 10 yards distance from muzzle to target face.
Using a Winchester "modified" screw-in choke:
1. Eley Alphamax, 8 1/8 inches, nicely spread out.
2. Spartan, 9 5/8 inches, one pellet lost off target. I flinched left firing this one!
3. Winchester, nicely centered 4 inch group with flyer taking it out to 5 1/4 inches, still nice!
Using a Carlson's full choke screw-in:
1. Eley, 7 1/4 inches, rounded group not evenly dispersed.
2. Spartan, lost one pellet, 7 1/2 inch pattern widely spread, flinched left again!
3. Winchester, 4 1/2 inch nicely centered, evenly dispersed. Flinched left AGAIN, but pattern was tight enough that no pellets were lost.
Using Winchester Turkey Extra Full screw-in choke:
1. Eley, 5 1/8 inches, tight 11 pellet group 3 1/4 inches, 12th pellet wandered off.
2. Spartan, 7 inches, pretty evenly distributed.
3. Winchester, 5 inch oblong.
Sure does take a long time to do this, waiting for the line to clear to change targets. One shot is not enough to base a case purchase on, but will shoot some more and extend the distance for promising loads.
Oh that is good stuff and awesome. Thank you for sharing. I have wondered those results in my head so I enjoyed reading your post.