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Most Online1,131 Jan 21st, 2024
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Joined: Mar 2004
Posts: 184 Likes: 1
Sidelock
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OP
Sidelock
Joined: Mar 2004
Posts: 184 Likes: 1 |
In a 20ga, what would you call a gun with 0.007 and 0.013 constriction? Several charts Ive looked up give several different answers. Best I can tell, it is between Sk/IC and IC/Mod.
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Joined: Jan 2002
Posts: 13,127 Likes: 1126
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 13,127 Likes: 1126 |
I'd call those constrictions IC and LM, but they may well shoot tighter than that with certain loads. What they really are can only be determined by the patterns from them.
SRH
May God bless America and those who defend her.
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Joined: Jan 2002
Posts: 621 Likes: 1
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 621 Likes: 1 |
A chart published by Brownells in 2001 gives constrictions for each gauge. They vary as smaller bores take less constriction to make choke.
The 20 Gauge is shown as:
Skeet .004 IC .006 Skeet 2 .009 Modified .014 Imp Mod .019 Full .025
Other charts seem to use the twelve gauge constrictions for every gauge, which is misleading.
My experience with several 20 bores supports the Brownell's chart.
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Joined: Dec 2001
Posts: 12,743
Sidelock
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Sidelock
Joined: Dec 2001
Posts: 12,743 |
As Stan stated the true choke is determined by flattering. As for bore constrictions, this should relate to a percentage of restriction, rather than a certain number of thousandths of restriction. Thus under old standards for card & filler wads, a full choke had about a 10% reduction. This amounted to around .040" for a full choke 12, but only around 032" for a full choke 20. Note these percentages have t be worked using the Square of the bore diameter, not the actual size.
Miller/TN I Didn't Say Everything I Said, Yogi Berra
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Joined: Jan 2002
Posts: 11,372 Likes: 103
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 11,372 Likes: 103 |
I have two charts (one from Mike Orlen and another from the late barrel guru Stan Baker) that match quite closely with Little Creek's numbers for the 20ga.
However, there was significant variation from one maker to another. Belgian Brownings, for example, tended to be choked tighter than guns from other makers. In his "Shotgun Book", Jack O'Connor listed choke constrictions used by Browning, Winchester, and Remington. Browning's 20ga full choke constriction was .033, while Winchester's was .027. Browning's 20ga full choke actually had more choke than Winchester's 12ga full (.031). And anyone who has measured constrictions on a Parker Reproduction 28ga will find that the Japanese must have been using full choke numbers on those guns. WAY tighter than standard.
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Joined: Apr 2018
Posts: 316 Likes: 70
Sidelock
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Sidelock
Joined: Apr 2018
Posts: 316 Likes: 70 |
and the french really believe in tight choking....typical field guns are full choke on right,.. and full and then some on the left....
"it's a poor sort of memory that only works backwards." lewis carroll, Alice in Wonderland
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Joined: Nov 2006
Posts: 3,431 Likes: 34
Sidelock
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Sidelock
Joined: Nov 2006
Posts: 3,431 Likes: 34 |
And the early fixed choke Citori 12s were very tight. My first Citori was marked M/F and shot more like Xtra Full and Turkey Full.
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Joined: Jan 2002
Posts: 11,372 Likes: 103
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 11,372 Likes: 103 |
and the french really believe in tight choking....typical field guns are full choke on right,.. and full and then some on the left.... Yet you'll also find French doubles--usually made with woodcock hunting in mind--that have one rifled barrel. The purpose of which isn't to shoot a slug, but rather to produce a pattern that's even more open than cylinder.
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Joined: Mar 2004
Posts: 184 Likes: 1
Sidelock
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OP
Sidelock
Joined: Mar 2004
Posts: 184 Likes: 1 |
Thanks guys. Completely agree with patterning being the final determinant. Looking at acquiring a gun for hunting out west and chokes less than IC/Mod start to lose utility pretty quick. I suppose I have the choke tube option as a last resort.
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