Velocity vs barrel length

[gcs71]

Anyone have that stats on velocity vs shotgun barrel length. It seems to me that once the shotshell powder charge is completely burned up, in say, the first 18 or 20 inches of the barrel, then barrels longer than that would only slow the shot column down due to friction/drag. Is there a formula for such calculations? I know this to be true with rifles where the bullets actuall touch the lands in a rifle bore. Is there a standard barrel length that manufacturers use to determine shotshell velocity? I would like serious answers only ..... well, on second thought..... we may as well hear the idiotic answers as well since it has been quite slow and boring on here latley.

[MudderGoose]

This dude says na

http://wegners.com/shotdir/spdvslen.htm

[Johnsonevinrude]

http://www.fieldandstream.com/article.jsp?ID=1000032394&typeID=2353&categoryID=2548

[BRACKET "Myth #4"]
Long barrels don't increase velocity. You will read that powder burns entirely in the first 18 to 19 inches of the barrel, so any additional barrel length has no effect on velocity. Untrue: Shotshell velocities don't change as dramatically as do rifle velocities as barrel length increases or decreases, but they can differ a few feet per second per inch of barrel, especially with the slow burn-rate powders used in many steel loads. Bear in mind that manufacturers typically list shotshell velocities based on results from a 30-inch test barrel. If you're one of those who shoots a little stubby thing in the duck blind, your 21-inch-barreled gun may be shooting measurably slower than the 30-inch-barreled pumps and autos on either side of you using the same ammunition.

[RIVER RAT]

all of the stuff that i have ever read was 25 ft faster per inch. i have seen this number alot. i personaly have never tried testing it.

[Mark Spence]

http://www.fieldandstream.com/article.jsp?ID=1000032394&typeID=2353&categoryID=2548


Long barrels don't increase velocity. You will read that powder burns entirely in the first 18 to 19 inches of the barrel, so any additional barrel length has no effect on velocity. Untrue: Shotshell velocities don't change as dramatically as do rifle velocities as barrel length increases or decreases, but they can differ a few feet per second per inch of barrel, especially with the slow burn-rate powders used in many steel loads. Bear in mind that manufacturers typically list shotshell velocities based on results from a 30-inch test barrel. If you're one of those who shoots a little stubby thing in the duck blind, your 21-inch-barreled gun may be shooting measurably slower than the 30-inch-barreled pumps and autos on either side of you using the same ammunition.



I would say that sums it up....and I can honestly say, I have heard from several gunsmiths, that with [b]steel loads, the longer the barrel, the faster the velocity. We not talking majorly higher velocities here...much like RiverRat stated, somewhere in the neighborhood of 20 - 25 FPS faster.

But, the statement from Field and Stream is probably the best I have heard it put.

[BadCaller]

Tom Rooster the guru of non tox shot settled in on 26" for powder burnt. One factor that in not being mentioned is Backbored barrels and wad selection. The tighter the bore your going going to get a little higher FPS. Take the same barrel with a 2 piece wad against a 1 piece wad and the solid wad will always shoot faster. If any of you guys handload you know what I am talking about.