Low vs high velocity shot patterns

[MoonJeong]

I'm going to go pattern my shotgun later this week, but I've noticed from slo motion video that when I shoot 1145 fps loads, the pattern is much more dense than when I shoot 1300 fps loads. As a mater of fact, the 1145 loads look like they never make it out of the wad as the video shows a black blob and no wad falling out... on the 1300 fps, the wad clearly separates and the shot spreads.

[Philip Dedmon]

Keep us posted.

 

At about what distanced does the wad separate on the 1300's?

 

BTW,,,,, have you chronoed those loads to come up with 1145 & 1300 or this that what is on the box?

[JD45]

Yep that's usually the way it works. 

 

Read Bob Bristers book, Shotgunning, the Art and the Science. It's all there. 

[12glocks]

Or even the Lyman Shotgun Loading Manual.  Cliff notes version:  pellet deformity is the primary cause of poor patterning or flyers.  Pellet deformity increases with higher velocity, higher weight shot charges, softer shot, or tighter constriction.  So higher quality chokes that do not constrict so abruptly, shot buffers, nickel plated shot, standard velocities etc tend to increase pattern density and uniformity. 

[MoonJeong]

To answer questions, I’m going with box rating in velocity. I shot aa 8 shot at 1350 vs 7.5 at 1145 and can confirm that the higher velocity is less even and spreads more. Could be the 8 vs 7.5 but that’s all I had. The 7.5 at 1145 was very consistent and nice tight pattern from 25 yards and full. The 1350 had less dense pattern and flyer pellets outside the 30” circle. 

[Philip Dedmon]

Here is what I have chronoed lately, out of my 32" 425 Browning at about 16" from the chrono.

 

Rio Target Load, 1 oz. 7.5 @ 1280 fps on the box

I got, 1390 fps. 5 shot avg.

 

Fiocchi Shooting Dynamics, 1 oz. 7.5 @ 1250 fps on the box

I got, 1313 fps. 5 shot avg.

 

Fiocchi Shooting Dyamics, 1 1/18 oz. 7.5 @ 1165 fps on the box

I got, 1265 fps, 5 shot avg. 

[hitman]

How many oz shot load 1, 1 1/8 ect?

[lefty o]

lighter loads, and slower loads tend to throw tighter/more dense patterns.

[MoonJeong]

On 9/6/2018 at 7:01 PM, Philip Dedmon said:

Here is what I have chronoed lately, out of my 32" 425 Browning at about 16" from the chrono.

 

Rio Target Load, 1 oz. 7.5 @ 1280 fps on the box

I got, 1390 fps. 5 shot avg.

 

Fiocchi Shooting Dynamics, 1 oz. 7.5 @ 1250 fps on the box

I got, 1313 fps. 5 shot avg.

 

Fiocchi Shooting Dyamics, 1 1/18 oz. 7.5 @ 1165 fps on the box

I got, 1265 fps, 5 shot avg. 

How do you chrono shotloads? Same as metallic?

[MoonJeong]

1 hour ago, lefty o said:

lighter loads, and slower loads tend to throw tighter/more dense patterns.

Thats what i saw. Mich more consistent with slower loads.

[lefty o]

you chrono just like metallic, but be advised its best to put a piece of plexiglass over the readout, for protection against the wad.

[MoonJeong]

On 9/9/2018 at 12:23 AM, lefty o said:

you chrono just like metallic, but be advised its best to put a piece of plexiglass over the readout, for protection against the wad.

Thanks - will have to try now.