[cottontop]

There sure are a lot of shotgun myths still floating around. Some it even sounds like it would be true. The late Bob Brister did a lot of shotgun research and experimentation and wrote a book on his discoveries titled Shotgunning, the art and Science. In it, he he proves these myths for what they are: myths. Barrel length does not have any influence on pattern or velocity; only the choke can affect the pattern and only the load in the shell can affect velocity. The choke will not have any influence on recoil. We are only talking a few thousandths of an inch here; not enough to make a difference in pressure, but enough to affect the pattern spread or tightness.

[Virginian]

Just what edition of Bob's book do you have that says barrel length has no effect on velocity? I have also chronographed a bunch of loads myself, and it does make a difference. Just not a big difference. I did not test anything as short as 18" because I don't own anything close.

[cottontop]

Originally Posted by Virginian

Just what edition of Bob's book do you have that says barrel length has no effect on velocity? I have also chronographed a bunch of loads myself, and it does make a difference. Just not a big difference. I did not test anything as short as 18" because I don't own anything close.

Don't want to be splitting hairs here. I should have left "velocity" out of that sentence. You are correct, barrel length of a shotgun has some effect on velocity, just not a lot. But still, barrel elnght has no effect on patterns as only the choke can do that.
cottontop

[natman]

Originally Posted by willfully armed

Patterns open faster from a shorter barrel. FACT

OK, offer some proof.

[gunkid9mm]

If you compare two barrles, one is ten inches longer than the shorter one, the pattern of the one that is ten inches longer will start to open up ten inches after the shorter one, but from the muzzle they open at the same rate...? So saying that a shorter barrle produces patterns that open faster is like saying that my car will drive faster if the front of my car is longer because it will arive at the destination faster than if it was of a shorter lenght... Dose that make sense???
I am asuming we are talking about barrles of leagle shotgun leangth, ofcourse ballistics change when using a really short barrle, like a taurus judge shooting .410 shotshells.
This is how i interpeted it, please correct me if im wrong, i dont claim to be an expert at any of this, im just a little confused and am trying to get this whole "barrle lenght effect on pattern" thing figured out. Thanx to all who shared opinions on my origional question.

[ROENIGK]

Originally Posted by JTJ

You are restricting the barrel at the muzzle so you are going to get a pressure increase which means a recoil increase. You can really feel it with a slug going through a choke over a cylinder bore.

Sounds rite. There's a smaller space for the same amount of lead/steel to squeeze out of so there would be more pressure as a result.

[tonydewar]

Originally Posted by cottontop

Don't want to be splitting hairs here. I should have left "velocity" out of that sentence. You are correct, barrel length of a shotgun has some effect on velocity, just not a lot. But still, barrel elnght has no effect on patterns as only the choke can do that.
cottontop

we are splitting hairs barrel length will affect velocity .wich will also affect pressure witch affects felt recoil and pattern spread also. so the anser is to pattern your gun with the load you plan to shoot . you may be surprised

[kirbythegunsmith]

Absolute fact that a longer barrel, with equivalent choke, will pattern tighter than a shorter barrel, with all else being equal.
This is due to the pressure drop in the barrel as length increases causing less shot column disruption (once it clears the bore) by the "jet effect" of the gas after the wad clears the crown. That releases the gas to freely accelerate and "impact" the rear of the wad/shot stack. This effect will be more pronounced when none or little choke is present, since the shot has minimal or no choke effect that de-couples the pellet stack somewhat, and moreso in a tight choke.

The choke has a recoil effect by having the fuller choke act as a more efficient rocket nozzle to increase the efficiency of the jet effect by the gas venting out the muzzle.
That is why porting will have some small effect on recoil and sometimes cause increased pattern density - by reducing the gas jet rocketing out the muzzle.

kirbythegunsmith@hotmail.com