Shotgun Chokes

[FinBusDev]

Can someone tell me how the pellet pattern of a 20 gauge shotgun with no choke compares to a 12 gauge with a choke?
Assume 1 oz loads in both cases. Seems to me the narrower barrel of the 20 gauge provides a natural "choke" no?

 

[kev74]

It's going to depend on the individual shotguns. There's no way to really tell without patterning them.

Does the 20 gauge have the choke removed, or is the choke constriction built into the barrel?

 

[GTN]

Also how long are the barrels?

 

[tony]

@FinBusDev,

At what distance ? Shot or pellet size matters too.

Generally a shotgun with no choke, called "cylinder bore ", will provide a more open pattern than most any choked barrel.

 

[FP1201]

Somewhere I've got a Book by Greener (Fine English Shotgun Makers) that delves extensively into a subject most dismiss as simplistic.
20 gauge guns are favored by Hunters relegated to Shotgun (Slugs) only because they seem more accurate with relatively the same projectile weight and velocity.
I don't have the exact answer, and it'll take some time to figure out who I lent the Book to last, but the ideal of a similar weight, shot size, and velocity from a smaller diameter is plausible.

 

[Bustedknees]

The barrel should be marked. Full, modified, improved ??

 

[FP1201]

The barrel should be marked. Full, modified, improved ??

I believe his question was about how the same one ounce of shot from a twenty gauge performs versus the same load from a twelve irrespective the chokes. ie would a 20ga pattern better than a 12 without a choke being how the 20 is much smaller.

 

[FinBusDev]

I believe his question was about how the same one ounce of shot from a twenty gauge performs versus the same load from a twelve irrespective the chokes. ie would a 20ga pattern better than a 12 without a choke being how the 20 is much smaller.

Correct

 

[Robin]

The unchecked barrel won't pattern for shit, especially a modern short barreled gun.
I have experimented quite a bit with smoothbore black powder barrels that are 42-44" long. just a quick re-cap, at 25 yards a 44" barrel un-choked will give you a pattern that is pretty iffy even on a turkey sized animal, the same barrel with a jug choke equal to a " full choke will give you an acceptable pattern out to 35 yards. Over simplified and in practical terms, but should give you an idea of how it works.
For those not familiar with the term "jug choke"

The diameter of the expansion area determines the choke, full choke is approximently .030 over bore diameter.
Robin

 

[FinBusDev]

thank you