choke

[potter]

Whats the tightest 10 gauge choke?  Is the no written on the choke the difference between barrel dia. And choke dia.? And if that is true why are moss 12gauge overbored barrels(10 GAUGE BORE) choked in such small sizes? Are all 10 g barrels 3/4 in? Just saw a chart on choke restriction stated .040 is extra full. Im confused.

[457121]

 Hastings made .680" and .675" 10ga. extended turkey chokes. These were the tightest I've seen. The overbored/back bored 12ga. barrels are around .742". Any larger than that the wad's gas cup wouldn't seal in the bore. So truth be told no 12ga. has a 10ga. bore despite what the manufacture's like to claim even using the minimum English or Japanese standard. No, USA made 10ga. barrels are not 3/4" (.750''), the US standard is .775" minimum. Using the .775" US standard, cylinder is .775", imp cyl is .766", mod is .757", full choke is .740", extra full .735" or so. These can vary a few thousands. Hastings used these dimensions in their flush mount screw in's based off a .775" bore:
cyl .775"
sk1 .767"
imp cyl .759"
sk2 .751"
mod .743"
imp mod .735"
full .725"
x full .717"
I personally find the Hastings dimension chart closer to what you would think it should look like on the patterning board (with lead loads). I have a H&R model 176 10ga. with a .740" fixed full choke that has patterns which are best described as a modified/imp. mod spread no matter what lead ammo is used. The .740"- .735" fixed chokes that most 10ga. single shot and doubles have are not tight enough for my liking for turkey hunting. Having said that my H&R and Spanish SxS fixed choke guns have killed a lot turkeys since the '80's.
I have shot a lot of lead shot patterns through a BPS and an Ithaca Mag 10 with grafted on Remington SP 10 Rem choke barrel using Hastings tubes. If I had to pick an all around fixed choke dimension for a 10ga. barrel it would be .720"-.725" for lead loads. With screw in chokes i like the .705" for turkeys. A .695" does work well with #5 lead or smaller though. I only use the standard bead sights on my shotguns so I'm not interested in softball sized patterns at closer ranges with tighter chokes.

[10gaugemag]

Something tells me the Browning guns have a .785 bore.

[potter]

He number stamped on the choke, is that the choke dia.?

[10gaugemag]

It either the exit diameter or amount of constriction.

[potter]

 I think its the exit dia. The constriction no. Is the barrel dia. Minus the exit dia.(choke dia.). I just sent a barrelto briley to be threaded and I get to pick 3 chokes, I hope to pick them by exit dia., but they keep confusing me with choke constriction nos.they should get my barrel next week.thats why im trying to undrestand what these nos. Mean.

[10gaugemag]

https://trulockchokes.com/basic_choke_information.html

Scroll down to choke chart. Same amount of constriction regardless of gauge.

What type shot and size are you planning to shoot?

[potter]

Thanks for the info. I am going to use nitro tss 8&9 shells.if my barrel dia is .775 and I subtract .045(amount of constriction for extra full, from chart) I get .73. Which should be exit dia of choke. This seems to be to large a dia. For an extra full choke. Am I missing something? Barrel dia..775 minus constriction ex full .045 equals .73 choke dia. ?

[10gaugemag]

You are correct, that is how extra full measures out. The tighter choke you are thinking of is more of what most would call a "turkey"  choke.

I would ask the shell manufacturer if they have any recommendation as to what E.D. to try.

[potter]

Thanks for the help. I learned alot. When briley calls me , I now  have a better understanding of what I want to do.when he measures my dias. I will have a good idea of how much tighter I want for new chokes.

[10gaugemag]

Don't discount how effective the full .040 or extra full. 045 can be.

My factory full Invector is very good with 2 1/4oz Remington loads. Excellent for Turkey's in the timber.

[potter]

Briley got back to me. My barrel dia. Is .768 with fixed chokes .723 dia. ? 045 constriction x full. Im threading barrels

and picked 3 extended chokes
               
          .700 DIA.   .068 constriction
          .710.          .058
          .715.           .053
they thought these were extremely tight chokes .too tight in there opinion. There constriction chart ends at .045 which they call extra full.whats everybodys opinion on here?hoping I dont bulge barrels.

[deadbuck]

Here are some pics of my 10 ga barrel that I had threaded. I wouldn't worry about bulging a barrel if your chokes extend as far out the end of the barrel as mine do. Looks like most of the constricting is taking place outside the end of the barrel and inside the choke tube. My barrel was .745 to begin with and the tube shown is a .685 so that would be .060 constriction.

[potter]

Who threaded the barrel? I never saw a choke with the tapered end outside.

[deadbuck]

Mike Orlen threaded the barrel and Sumtoy made the choke. It had to be Tru Choke thread pattern (.865x44) because of thin barrel thickness. If you screw a standard modified or full Tru choke tube in the barrel it fits flush with the end of the barrel just like any other factory choke on any gun. The problem with Tru Choke thread patterns is nobody uses it nowadays. Kind of like buying an Edsel car in 2018