S |
M |
T |
W |
T |
F |
S |
|
|
|
|
|
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
11
|
12
|
13
|
14
|
15
|
16
|
17
|
18
|
19
|
20
|
21
|
22
|
23
|
24
|
25
|
26
|
27
|
28
|
29
|
30
|
|
|
|
|
|
|
|
2 members (SKB, AP Smith),
522
guests, and
6
robots. |
Key:
Admin,
Global Mod,
Mod
|
|
Forums10
Topics38,576
Posts546,570
Members14,424
|
Most Online1,344 Apr 29th, 2024
|
|
|
Joined: Nov 2015
Posts: 1,124 Likes: 19
Sidelock
|
OP
Sidelock
Joined: Nov 2015
Posts: 1,124 Likes: 19 |
What would be the stardard constrictions for a 20ga? I have a barrel that measures .605 and .617. I understand that numbers dont make the pattern, I'm just looking for a reference. It seems most newer guns with tubes have different numbers, would fixed chokes measure the same ?
|
|
|
|
Joined: Dec 2001
Posts: 2,961 Likes: 9
Sidelock
|
Sidelock
Joined: Dec 2001
Posts: 2,961 Likes: 9 |
Back in the day when Winchester was an American Co. the chokes for a 20 were : Bore = 617, full = .025, mod = .014, ic = .006
bill
|
|
|
|
Joined: Oct 2004
Posts: 1,826 Likes: 12
Sidelock
|
Sidelock
Joined: Oct 2004
Posts: 1,826 Likes: 12 |
If your bore is .617, then you'd have cyl. and mod. according to Bill.
|
|
|
|
Joined: Dec 2001
Posts: 12,743
Sidelock
|
Sidelock
Joined: Dec 2001
Posts: 12,743 |
.615 is nominal 20 ga so @ .617 Win was using a .002" overbore. Measuring "Just the Choke" is never of any value at all, the bore also has to be measured to determine amount of constriction. Bores varied all over the board from Nominal, even among guns of the same make at different points in time. When used as a % of bore reduction .025" in a 20 gauge is = to .030" in a 12ga. In the old days of card & felt/fiber wads this was considered IM, but with modern plastic obturating wads with shotcups it is considered full.
Miller/TN I Didn't Say Everything I Said, Yogi Berra
|
|
|
|
Joined: Jan 2002
Posts: 5,954 Likes: 12
Sidelock
|
Sidelock
Joined: Jan 2002
Posts: 5,954 Likes: 12 |
RAR, the numbers do indeed tell the tale for patterns. That is, the measured constrictions. Beyond that, there are very few factors that influence pattern performance. The problem with patterning is that patterns are highly variable. You need 10 statistically analyzed patterns to say with confidence how the gun+load performs. Considering that a Cyl at 30 yards and a Full at 40-45 yards are equivalent, it is less of an issue than is commonly thought. If you aren't willing to do 10 patterns per load+gun with the "Shotgun Insight" program, then in the words of the immortal Tony Soprano, "Fugidaboutit."
DDA
|
|
|
|
Joined: Feb 2008
Posts: 519 Likes: 4
Sidelock
|
Sidelock
Joined: Feb 2008
Posts: 519 Likes: 4 |
It has been my observation that choke tubes with XX amount of constriction generally pattern tighter than a fixed choke with the same constriction. My surmise is that because the bases of the tubes are essentially upset relative to the bore, they allow the charge to open up just a bit before encountering the actual choke portion of the tube. In a tubed gun I will typically use a step more open choke than what seems natural.
|
|
|
|
Joined: Mar 2002
Posts: 7,744 Likes: 496
Sidelock
|
Sidelock
Joined: Mar 2002
Posts: 7,744 Likes: 496 |
Choke tubes are slightly over bored on the chamber side. It was explained to me this was done so the wad never gets caught by the edge of the choke tube with dramatic results. So if a slight over bore segment causes tighter patterns using a more open choke tube would remove this effect. Perhaps you get tighter patterns from the tapering f he choke tube with a short parrel segment.
I think we over think chokes too much in all but extreme conditions. It's like shooters are thinking I missed that last shot because of my choke selection not because I did not put the pattern in the right spot. It's the Indian not the bow or arrows fault.
|
|
|
|
Joined: Nov 2015
Posts: 1,124 Likes: 19
Sidelock
|
OP
Sidelock
Joined: Nov 2015
Posts: 1,124 Likes: 19 |
Thanks guys and your right it is easy to over think it. I was just curious what the standards were for a 20ga. I think I got it!
|
|
|
|
Joined: Mar 2002
Posts: 3,106 Likes: 339
Sidelock
|
Sidelock
Joined: Mar 2002
Posts: 3,106 Likes: 339 |
Be strong, be of good courage. God bless America, long live the Republic.
|
|
|
|
|