Choke comparison

Open discussion on all things 16 Gauge.

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manchap
Posts: 58
Joined: Sat Dec 03, 2016 1:19 pm

Choke comparison

Postby manchap » Fri Oct 30, 2020 4:56 pm

Hello im thinking of new choke for tss but what does is .555 equivalent ie 1/4 , 1/2 or 3/4 ? this will be a Inv plus.
at the moment i only have 1/4 factory and aftermarket extended 3/4 which ive found perfect with 24gram steel 3s .

Thank you



Dave in AZ
Posts: 186
Joined: Thu Mar 10, 2016 1:38 pm

Re: Choke comparison

Postby Dave in AZ » Fri Oct 30, 2020 5:44 pm

Not sure what you mean by .555 equivalent... Looks like you left a zero off there, that's 1/2inch of choke! Maybe you're talking about a 28ga, which has a nominal 0.545" barrel diameter, but can be plus 0.02" more for tolerance. Still, 0.555 would be and increase in diam, don't think 28ga has increased diam in invector plus.
(See how much ambiguity can be avoided by you throwing in a bit more info in your post, like what GAUGE you're asking about?)

Also sounds like the nomenclature used where you are is different. No one uses quarter, half, etc. in the US. Here is a list from Carlson's choke tubes on common US terminology and choke amounts:
Generally 12ga and 20ga choke constrictions follow the chart below.
CONSTRICTION NAME CONSTRICTION MEASUREMENT (.000 of an inch)
Cylinder .000 (Bore Diameter which vary on manufacturer/model)
Skeet .005
Improved Cylinder (IC) .010
Light Modified (LM) .015
Modified (MOD) .020
Improved Modified (IM) .025
Full .030
Extra Full (EF) .040
Turkey (TKY) .045+



Additionally, there is quite a bit of argument about how chokes should be named/called-- from the actual physical constriction of the choke vs. the actual bore of that shotgun, or based on the observed pattern % they deliver at 40yds. There is a good argument that if you tell someone a choke is "modified", you are saying that at 40yds it delivers 60% of the lead pellets. That was always the standard definition, not constriction, until folks started shooting steel and were getting different %s from the same choke with lead and steel, and began talking about constriction instead.

The standard 12ga bore is 0.725 + .02 tolerance max. But many manufacturers are doing "backboring", and Browning/Winchester both use 0.742 as their standard invector barrel size. So it's not enough to say some amount of constriction, you need to report or request what the actual inside diameter of the choke is AND what the barrel diam is of the gun you're using, to derive the ACTUAL choke amount.

Anyways, you said Invector plus, and I assume 12ga? But choke tube choice is all about what pattern you're trying to get. Are you after turkey, or ducks? Super tight at 40yds, or 70% at 40 yds? Most folks are using CYL, so 0% choke, for TSS, at the most Improved Cyl., which deliver very tight patterns using TSS. But most patterns here at this site are for turkeys, trying to hit a turkey head at 40 yds with 400 pellets in a 10" circle... while everything I discuss and talk about with friends is how to get the TSS pattern to bloom to 30" so we don't destroy a duck.

Here's another good writeup on choke from Trulock Chokes, and this has a chart for British 1/4 etc. terms vs. constriction down at the bottom:
https://trulockchokes.com/basic_choke_information.html



manchap
Posts: 58
Joined: Sat Dec 03, 2016 1:19 pm

Re: Choke comparison

Postby manchap » Sat Oct 31, 2020 9:51 am

Dave i do appolgizie for the lack of info,Im a person of very few words lol
I am using a 20g Browning gold and the mainly after flighting Large geese and duck. I am used to 12g choke constrictions but having moved over tp the 20g and 28g still be new to me.



Dave in AZ
Posts: 186
Joined: Thu Mar 10, 2016 1:38 pm

Re: Choke comparison

Postby Dave in AZ » Sat Oct 31, 2020 5:11 pm

From that article I posted that has British nomenclature cross-referenced, a choke of 005 would be called skeet one here, but in the UK would be called improved cylinder. In the US what we call improve cylinder you would call 1/4.

4 steel shot, I use skeet one, .005, for most of my shooting. I would also use this 4 TSS shooting if I wasn't using cylinder.



manchap
Posts: 58
Joined: Sat Dec 03, 2016 1:19 pm

Re: Choke comparison

Postby manchap » Sat Oct 31, 2020 5:18 pm

Thank you Dave



Greg
Posts: 43
Joined: Fri May 31, 2019 7:25 am

Re: Choke comparison

Postby Greg » Sun Nov 01, 2020 10:50 am

A .555 is likely a turkey choke and an extremely tight one at that in an invector plus shotgun. I would be cautious shooting any hard shot (steel or tungsten) through something that tight.



manchap
Posts: 58
Joined: Sat Dec 03, 2016 1:19 pm

Re: Choke comparison

Postby manchap » Sun Nov 01, 2020 11:34 am

Thank Greg




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