Choke Question

[4535jacks]

I measured my the chokes on my AYA using callipers and they came out as 1/4 and 3/4 which I think is a great game setup.  This is the reading I get for my chokes from a simple drop in choke gauge.

However I was in the gunsmith today and they said it is not the absolute diameter that determines the choke but rather the restriction from the bore's nominal diameter.  They measured the diameter of my barrels which are then the chokes to work out the restriction which came out as IC and 1/2 - not as good for driven game in my opinion.  

The more I think about it, it is the diameter of the choke rather than the restriction that from the bore diameter that really matters as this will ultimately determine the width of the shot string.

So if a shotgun barrel has a diameter of 0.730" and the muzzle diameter is 0.72" it has a 0.010" restriction I.e 1/4 Choke.  However if another gun has a barrel diameter of 0.725" and also a muzzle diameter of 0.72" it has a restriction of 0.05" i.e Improved cylinder.  So these two barrels have exactly the same muzzle diameter meaning the shot string width, pattern and shot density should be the same yet they have different chokes.

So what determines the choke, muzzle diameter or restriction from nominal barrel diameter recognising that barrels can vary slight in diameter? 

Edited November 6, 2018 by 4535jacks

[gotgcoalman]

Can you hit consistantly with it?

I always thought it was the last few inches of the barrel internal dia denoted the choke ?

[4535jacks]

Don't know.  Find out tomorrow!  I have just bought it hence why I trying to find out the chokes.  When I bought it it was told it was 1/4 and 3/4 but seeing the gunsmith today (just have the gun checked over) I am in doubt whether this is true.

[figgy]

Choke is measured against the nominal bore diameter, every ten thou tighter is one quarter of choke. 

But true choke is the pattern thrown with your chosen cartridge. 

Have a read of some past choke topics on the forum. 

I understand what your saying about muzzle diameter but that’s not how choke works. 

For driven game guns your tightest choke should be in your right side barrel fired first but I bet your AYA isn’t like that. Not many guns are, my sxs isn’t its 1/4 choke first then 1/2 second barrel. I never think about it and just shoot. 

Edited November 6, 2018 by figgy

[Andy H]

The amount of choke is defined by the amount of constriction from the internal barrel diameter   before the choke starts , IE:  the barrel is .730" bore all way up to where the diameter starts to get smaller for the choke  with the final  diameter at  .710" then you have a .020" choke constriction.

[matone]

3 hours ago, 4535jacks said:

Don't know.  Find out tomorrow!  I have just bought it hence why I trying to find out the chokes.  When I bought it it was told it was 1/4 and 3/4 but seeing the gunsmith today (just have the gun checked over) I am in doubt whether this is true.

I`d forget about it and shoot it first ,AYA`s are known to continue to shoot tight even after having constriction removed and need the choke profile altering to achieve much reduction.

Imp/1/2 would be perfect for driven anyway,I`d have thought ...

[TIGHTCHOKE]

7 hours ago, 4535jacks said:

I measured my the chokes on my AYA using callipers and they came out as 1/4 and 3/4 which I think is a great game setup.  This is the reading I get for my chokes from a simple drop in choke gauge.

However I was in the gunsmith today and they said it is not the absolute diameter that determines the choke but rather the restriction from the bore's nominal diameter.  They measured the diameter of my barrels which are then the chokes to work out the restriction which came out as IC and 1/2 - not as good for driven game in my opinion.  

The more I think about it, it is the diameter of the choke rather than the restriction that from the bore diameter that really matters as this will ultimately determine the width of the shot string.

So if a shotgun barrel has a diameter of 0.730" and the muzzle diameter is 0.72" it has a 0.010" restriction I.e 1/4 Choke.  However if another gun has a barrel diameter of 0.725" and also a muzzle diameter of 0.72" it has a restriction of 0.05" i.e Improved cylinder.  So these two barrels have exactly the same muzzle diameter meaning the shot string width, pattern and shot density should be the same yet they have different chokes.

So what determines the choke, muzzle diameter or restriction from nominal barrel diameter recognising that barrels can vary slight in diameter? 

Measuring the choke is only a guide and using a drop in gauge is a poor guide. Read what Figgy has written.

7 hours ago, figgy said:

Choke is measured against the nominal bore diameter, every ten thou tighter is one quarter of choke. 

But true choke is the pattern thrown with your chosen cartridge. 

Have a read of some past choke topics on the forum. 

I understand what your saying about muzzle diameter but that’s not how choke works. 

For driven game guns your tightest choke should be in your right side barrel fired first but I bet your AYA isn’t like that. Not many guns are, my sxs isn’t its 1/4 choke first then 1/2 second barrel. I never think about it and just shoot. 

A Pattern Plate with properly measured distance and 10 shots of a chosen cartridge through each barrel at separate pieces of cardboard, paper or a repainted plate will allow you to determine the degree of choke within your barrels. Be aware that different makes and types of cartridge will make changes.

 

Ultimately if the gun fits you and kills game then that should be good enough. Don't get hung up on choking. get out and shoot, stick to a good cartridge that works for you.

[Hamster]

8 hours ago, figgy said:

Choke is measured against the nominal bore diameter, every ten thou tighter is one quarter of choke. 

But true choke is the pattern thrown with your chosen cartridge. 

 

Correct, choke denomination is decided by measuring tools but actual choke performance has to be tested by counting holes on a patterns sheet at 40 yards blah blah, sadly the latter is not 100% accurate though because even on the same day shot to shot variations can and will mean a difference in percentage densities of +/- one choke denomination meaning your tight barrel may print a 5/8th or tighter in one shot and a 1/2  the next !!

Then there's the further complication of different air densities giving variable results not to even mention the fairly vast results different cartridge brands/types may give. 

I long ago came to the conclusion that what matters with chokes is the visible results you get when shooting, be it live game or clays. Shoot the gun and see if your tight barrel will fetch 40-50 yard birds and kill them humanely and whether your more open barrel will kill at half those distances without smashing them, (they will almost certainly perform well regardless of whether they're academically measured or performing at ic/half or 1/4-3/4) because neither of those combinations is any worse or better for game shooting. 

[welshwarrior]

9 hours ago, 4535jacks said:

I measured my the chokes on my AYA using callipers and they came out as 1/4 and 3/4 which I think is a great game setup.  This is the reading I get for my chokes from a simple drop in choke gauge.

However I was in the gunsmith today and they said it is not the absolute diameter that determines the choke but rather the restriction from the bore's nominal diameter.  They measured the diameter of my barrels which are then the chokes to work out the restriction which came out as IC and 1/2 - not as good for driven game in my opinion.  

The more I think about it, it is the diameter of the choke rather than the restriction that from the bore diameter that really matters as this will ultimately determine the width of the shot string.

So if a shotgun barrel has a diameter of 0.730" and the muzzle diameter is 0.72" it has a 0.010" restriction I.e 1/4 Choke.  However if another gun has a barrel diameter of 0.725" and also a muzzle diameter of 0.72" it has a restriction of 0.05" i.e Improved cylinder.  So these two barrels have exactly the same muzzle diameter meaning the shot string width, pattern and shot density should be the same yet they have different chokes.

So what determines the choke, muzzle diameter or restriction from nominal barrel diameter recognising that barrels can vary slight in diameter? 

 

The pattern determines the choke but a useful guide (and normally accurate one) is the construction measurement.   

The muzzle diameter is the controlling factor this has been proved over years as well as by science but it’s imho one of those thinks that’s best just accepted 

[Gunman]

Why is there so much **** talked about chokes ? Either you can shoot a gun and hit your target or you cant . Blame the chokes is nothing more than an excuse for you missing  . Yes there are circumstances when too much or too little choke can be a disadvantage as can be the cartridge used , gun fit , stance and mount . 

But in my near half century in the gun trade the instances of the choke being wrong , and usually to much choke for the shooting done ,has been in the minority  of most shooters problems .

Take the gun out and shoot it if you worry that each time you pull the trigger that the choke is not what you think it should be YOU WILL MISS !

A mate of mine bought a gun he liked 40 plus years ago , he has shot all over Europe , Grouse , Pheasant ,Partridge ,Doves and Pigeons and Ducks and Geese .

Asked what choke the gun has he said he had no idea and didn't really care or want to know , "just point in the right direction and pull the trigger ."

[oldypigeonpopper]

13 minutes ago, Gunman said:

Why is there so much **** talked about chokes ? Either you can shoot a gun and hit your target or you cant . Blame the chokes is nothing more than an excuse for you missing  . Yes there are circumstances when too much or too little choke can be a disadvantage as can be the cartridge used , gun fit , stance and mount . 

But in my near half century in the gun trade the instances of the choke being wrong , and usually to much choke for the shooting done ,has been in the minority  of most shooters problems .

Take the gun out and shoot it if you worry that each time you pull the trigger that the choke is not what you think it should be YOU WILL MISS !

A mate of mine bought a gun he liked 40 plus years ago , he has shot all over Europe , Grouse , Pheasant ,Partridge ,Doves and Pigeons and Ducks and Geese .

Asked what choke the gun has he said he had no idea and didn't really care or want to know , "just point in the right direction and pull the trigger ."

hello, good reply gunman, but i must say back in the 1970s it was quite common to find a lot of foreign guns with half/full chokes and a tad tight for the average shot range so we had ours bored out to a more open choke  eg improved/1/2 or improved/3/4, our local gunsmith was kept very busy. 

[wymberley]

32 minutes ago, oldypigeonpopper said:

hello, good reply gunman, but i must say back in the 1970s it was quite common to find a lot of foreign guns with half/full chokes and a tad tight for the average shot range so we had ours bored out to a more open choke  eg improved/1/2 or improved/3/4, our local gunsmith was kept very busy. 

Yep, and TC by Imp or 1/4 wasn't unheard of. These are now the ones sitting on the RFDs' shelves unwanted. A word of caution though if the OP is a novice. You can read that this or that degree of choke is required for this or that shooting. Problem is though that much of this was written back along when the ranges were perhaps somewhat less than what we consider to be the norm today. As has been said, choke is not necessarily that critical but it is if you've unfortunately bought one of the guns mentioned above and which really isn't suited to your proposed shooting. Also it's beginning to look as though this obsession with faster and faster cartridges is having an adverse affect on pattern density and possibly quality. Whereas previously the ranges  which we shot at and the cartridge velocities were both such that choke really wasn't that critical and by and large often too much was employed. There are two other elements involved which have recently been covered on PW. One relating to fibre wads/ barrels and the other to (initially) fibre wads and maximum effective ranges. Both of these and the above, I feel, reflect that it's becoming more and more advantageous to take the benefits that the pattern plate has to offer if you real;ly want to know what's going on.

[AYA117]

Here is a good example of choke as to whether it really matters or is more psychological. A very good friend of mine, who is one of the top Clay sporting shooters in the country, looked at a stand and decided he needed ( something like ) 1/4 and 3/4 choke, after straighting the stand he found he had put the chokes in the wrong way round.

[Seadog1408]

^^^^^^^^^^ must have been hard to screw them in!!! ^^^^^^^^^^^

[AYA117]

He uses a hammer 

Ok in the wrong barrel, so the long distance clay got the 1/4 choke etc.

[4535jacks]

This has become less about me worrying about my choke but rather interested in the theory and how chokes work. As an engineer I don't like not being able to understand these things......

[Esca]

Mate of mine Has a Bretta 686 bought in '87' I watched him shotting one day bring down some beautifull high (not silly high) birds. At the end of the drive i asked what was the choke, his reply they were open. learnt my lesson now I don't worry about choke, but I do pattern my gun cartridge combination.

[wymberley]

17 minutes ago, 4535jacks said:

This has become less about me worrying about my choke but rather interested in the theory and how chokes work. As an engineer I don't like not being able to understand these things......

Should you discover how, say and write nothing until you've found a publisher who specialises in copyright because as yet no ones knows and you could be on a winner. The clue is if this weren't the case all chokes would be made to the same specifications, say, regarding cone length/ angle, etc, etc.

[B391]

This question of chokes is odd. So much debate. I just tend to stick in 1/4 & 1/2 and forget about it.  Mind you a friend of mine who is a truly excellent shot just shoots Cyl and Cyl whatever the distance and consistently hits well over 80%

[wymberley]

6 minutes ago, B391 said:

This question of chokes is odd. So much debate. I just tend to stick in 1/4 & 1/2 and forget about it.  Mind you a friend of mine who is a truly excellent shot just shoots Cyl and Cyl whatever the distance and consistently hits well over 80%

Don't doubt you for one minute. The problem is with anecdotes is that one is attempting to make a determination based on one example (but which may cover many occurences but just the one situation) for something where definitions are based on an average performance. The acid test is would it remain valid if everyone shot at everything with your friend's preferred choking which meets his needs?

[shalfordninja33]

Always an interesting debate. I use as open a choke as I feel I can get away with, on essex partridge and pheasant I use Briley Skeet and Improved Cyclinder, with 30gm no 7 Hull HP. Though by 80's era 686, 30 inch barrells.

It throws a nice consistent pattern on the plate which I have confidence in in the field. When I miss it's almost certainly me rather than a lack of choke and the closer birds aren't pillowcased, unlike some others that I've seen. 

Only Problem now is Hull have stopped making my favoured 30gm no 7. I managed to find two slabs to last this season, then I be changing to 30gm no 6.

Edited November 7, 2018 by shalfordninja33

[B391]

25 minutes ago, wymberley said:

 The acid test is would it remain valid if everyone shot at everything with your friend's preferred choking which meets his needs?

Agreed, he shoots a B525 and has had the same gun for years. He its quite annoyingly good. 

[wymberley]

11 minutes ago, shalfordninja33 said:

Always an interesting debate. I use as open a choke as I feel I can get away with, on essex partridge and pheasant I use Briley Skeet and Improved Cyclinder, with 30gm no 7 Hull HP. Though by 80's era 686, 30 inch barrells.

It throws a nice consistent pattern on the plate which I have confidence in in the field. When I miss it's almost certainly me rather than a lack of choke and the closer birds aren't pillowcased, unlike some others that I've seen. 

Only Problem now is Hull have stopped making my favoured 30gm no 7. I managed to find two slabs to last this season, then I be changing to 30gm no 6.

****** annoying, isn't it? I'm down to my last 2 slabs. If you'd rather stay with the 7s, you could just try some Gamebore Super Game High Birds. The last lot of the Hull I got were the penultimate loading with 350/oz - with the last lot this had dropped to 320 so as the Gamebore - where you're stuck with 28g -  are 350/oz you keep the pellet count up but lose a little poke. They're not quite in the same league, but I like them.

[shalfordninja33]

15 minutes ago, wymberley said:

****** annoying, isn't it? I'm down to my last 2 slabs. If you'd rather stay with the 7s, you could just try some Gamebore Super Game High Birds. The last lot of the Hull I got were the penultimate loading with 350/oz - with the last lot this had dropped to 320 so as the Gamebore - where you're stuck with 28g -  are 350/oz you keep the pellet count up but lose a little poke. They're not quite in the same league, but I like them.

Thank you for the info, I'll take a look at the Gamebore.

[Stonepark]

The last lot of Gamebore Black Gold and White Gold Fibre 28g clay cartridges, i had ran at 350/oz for their 7.5 (2.4mm).