Shot Pattern

[rodwha]

Does length of barrel change the shot pattern if the choke remains the same? I.e. would a cylinder bore Howdah 20 ga produce a similar pattern as a 24" 20 ga with a cylinder bore? I'd expect the Howdah's pattern to be slightly larger as the pellets are beginning to spread after they leave the shorter barrel but i wouldn't think it would have increased more than a few inches at say 15 yds.

 

[StrawHat]

It is the choke that determines the size of the pattern, not the barrel length. Length may or may not provide additional velocity.

 

[rodwha]

Might even velocity shape how quickly the shot spreads? Maybe not much at shorter distances, but once out to 20-25 yds could it begin to really show up?

 

[splattergun]

Yes, indeed velocity affects pattern. Don Zutz discusses it quite extensively in "Handloading for Hunters". Though this book was written with smokeless powder in mind, the principle is still the same. A "square load" balances the powder charge with the shot load, optimizing the velocity, which ultimately tunes the pattern. A bit less powder reduces velocity, which can result in a tighter pattern, perhaps too tight for the job. A bit more powder increases the velocity, perhaps to the point of blowing a hole in the middle of your pattern.

Apparently Zutz really enjoyed tuning his patterns by varying the powder charge.