Hoton Clay Club, Clay pigeon shooting in Leicestershire

While choke manufacture is a very exact science the effect of using a choke with a particular cartridge and gun combination is a bit of a dark art. In fact it is almost impossible to quantify exactly what effect you, your gun and your cartridge choice will achieve in the field. However, if it makes you feel better to fiddle about with the plumbing in the end of your gun for each and every stand then do so. Just don't hold up everyone behind you while you do it please.

Wow! What a relief we know all that stuff, but it still means you have to point your gun at the right piece of sky to get your 30 inch circle to coincide with the target!

The bottom line for chokes is, have I got enough pieces of shot with enough energy hitting my target at the range it is hit to break it?

The amount of spread of a shotgun pattern increases more with every yard the pattern travels, its area gets bigger by the square of the radius of the pattern. So a pattern 30 inches across has 706 square inches whereas a pattern just 40 inches across has 1256 square inches, or 80% more area to spread the pellets over.

If the target is far away the spaces between the pieces of shot are larger so fewer pieces of shot are going to hit it.

Also because the lead has travelled further it will also have slowed down due to the drag of the air so it carries less energy. The energy of a pellet is proportional to the square of its speed so when a pellets speed drops by say 25% from 1300 ft per second to 975 feet per second its energy falls to nearly a half!

You need a threshold amount of energy to break the target so you really need more pellets to strike the target not less!

Hence you need to apply more choke to longer shots to compensate for both the reduced numbers of pellets hitting the target and their lower energy.

Distance it the enemy of the shot gun and as the target gets further away the problem get worse ever faster!

So extra choke gets you a few more pellets onto the target but it cannot solve the problem of the lower energy that the pellets carry so it is an imperfect solution to the problem of distant targets.

You aren't done quite yet.

If your column of shot squeezes through the restriction of the choke it must be squeezed against the choke itself hard enough to constrict it. This is a considerable shock to the loosely packed shot.

Even though a full choke is only 35 thousandths of an inch your shot hits it at about 886 miles per hour (1300 feet per second). This shock wave disturbs the shot and breaks up the column and stretches it out slightly as it bangs and crashes it's way through the squeeze of the choke.

If the choke is crudely made the impact is made worse. If you have a well built gun or sexy after market choke tubes you will get a better passage of shot through the chokes with a better pattern of shot as a result. You will also reduce the amount of recoil you feel a little bit.

One last thing to remember: Your chokes have squeezed your shot closer together and this will reduce the size of your pattern for a more distant target.

This means that your margin for error has gone down.

You still have to shoot more accurately if the target is further away so the message is still “Shoot the right piece of sky” if you want to break targets, choke won’t help you with that, it will only help you get a kill when your shooting accuracy means you deserve it.

OK, all that lot applies if you are shooting lead shot.

But what if you what if you as shooting steel shot?

Compared to steel, lead is quite squidgy, soft, malleable. When it goes through your choke it squashes a little and the lead gives a bit to get through the smaller gap. This means that the back pressure behind the bung of lead shot doesn't get to high before the lead shot pops out of the end of the barrel. All's well then.

However steel shot is very much harder than lead shot and it doesn't squash much at all as it passes through a choke at the end of your gun barrels. As it struggles to get past the choke the pressure in the barrel builds up until the shot is forced out.

So what is the problem? Well if you shoot steel shot through a heavily choked gun barrel the back pressure can rise too far. This can mean straining the steel in the choke, the actual barrel and the threads around the choke. In extreme cases it could lead to the barrel bursting or the choke being ripped out of it's threads.

So, if in doubt....GO WITH YOUR GUN TO A QUALIFIED GUNSMITH AND GET HIM/HER TO TELL YOU WHAT IS SAFE TO SHOOT OUT OF YOUR GUN.

Don't ask your mate or take a vote on it, ask a gunsmith. He will check your gun's proof, wall thickness, choke, chamber length and general condition and then advise you on what your options are.

Steel shot is getting more common and maybe mandatory at some clubs so get the correct advice so you don't damage your gun or more importantly don't spray innocent bystanders with bits of the end of your barrels.

Here is a list of possibly interchangeable chokes. Consult your gunsmith about using anything other than the manufacturers original chokes.

American Arms Interchanges with Fausti/Traditions shotguns style threads

Austin & Halleck Black Powder Shotgun Interchanges with Winchester, Moss. 500 threads

Baikal/European American Arms Interchanges with Standard Tru Choke style threads

Benelli (Current production-square threads) Interchanges with Beretta style threads

Benelli Crio Interchanges with Sport II and SuperSport and Cordoba Produced prior to 2006

Benelli Crio Plus Interchanges with Super Black Eagle 2, M-2, Ultra Light and current Sport II, Super Sport & Cordoba

Benelli M-4 Interchanges with Ber/Ben standard thread

Beretta (Current Production) Interchanges with Beretta style threads

Beretta (Old style-no threads-uses muzzle cap) No known Interchange

Beretta Optima Interchanges with Optima threads (Models 391A Extrema & 12ga. 391 Teknys) Silver Pigeon II & III

Beretta Optima Plus Interchanges with Optima Plus threads (Models 391A Extrema and 12ga. 391 Teknys)

Bernardelli No known interchange

Black Diamond 12ga Interchanges with Ber/Ben standard thread

Browning Invector Interchanges with Winchester, Mossberg 500, Weatherby, Maverick 88, Smith & Wesson and Savage Guns style threads

Browning Invector Plus Interchanges with Browning Invector Plus, Winchester Super X2 and Winchester Supreme style threads

BSA Interchanges with Beretta/Benelli threads

BSA 20ga Silver Eagle Serial #201836 or higher is Ber/Ben if serial number is below, Huglu threads

Caeser Guerini Interchanges with Fab Arms

Century Arms/Kahn Centurion & Arthemis 12ga Interchanges with Berretta/Benelli

Century Arms/Kahn Centurion & Arthemis 20ga Interchange with Huglu style threads

Charles Daly Current Production Pumps, semi-autos, & Model 206 Interchanges with Remington Style threads

Charles Daly Current Production O/U Interchanges with Winchester style threads

Charles Daly S/S Field II, Model 306, & Model 106 Interchange with Beretta/Benelli style threads

Churchhill 12ga Interchanges with Fabarm style threads, some models American Arms Style threads

CZ USA 12ga Interchanges with standard Beretta/Benelli threads

CZ USA 20ga Interchanges with Huglu style threads

DeHaans 12ga Interchanges with Ber/Ben standard thread

DeHaans 20ga Interchanges with Huglu style threads

Fabarm 12ga Interchanges with Fabarm style threads

F.A.I.R. (I Rizzini) Interchanges with Verona LX threads

Franchi SxS Highlander & O/U SL series No known interchange

Franchi (Current production-square thread) Interchanges with Beretta/Benelli style threads

Franchi (Old Style-v threads) Pre 1999 Models Interchanges with Fran Choke style threads

H&R 1871/N.E.F. 12ga & 20ga Interchanges with Winchester, Moss 500 etc. threads

H&R Pardner Pump Interchanges with Winchester, Moss 500 etc. threads

H&R Excell Auto 5 Interchanges with Verona SX threads

Hastings Choke Tube 1 (Old Style) Interchanges with Tru-Choke

Hastings Choke Tube 2 (Current Version) No known interchange

Hatson Interchanges with Beretta/Benelli threads

Huglu 12ga Interchange with Beretta/Benelli style threads

Huglu 20ga Interchange with Huglu

Ithaca (Old Style-Fine threads) Interchanges with Tru-Choke style threads

Ithaca Model 37 (New Style 12ga.) Interchanges with Winchester style threads

Ithaca (All New Style 20ga.) Interchanges with Tru Choke style threads

Lanber 12ga Interchanges with Lanber style threads

Lanber Imported by American Arms Interchanges with American Arms style threads

Laurona (O/U) Interchanges with American Arms style threads

LC Smith 12ga (Marlin) Threads at top of tube are LC Smith Chokes, at bottom is American Arms

LC Smith 20ga (Marlin) Interchanges with Fran Choke threads

Legacy Sports Escort & Pointer 12ga Interchanges with Ber/Ben standard thread

Legacy Sports Escort 20ga Interchanges with Huglu style threads

Legacy Sports/Silma 12ga No known interchange

Luger No known interchange

Marrochi Golden Snip Field O/U Interchanges with Browning Invector Plus style threads

Maverick Model 88 Interchanges with Mossberg 500, Winchester and Browning Invector style threads

Miroku Interchanges with Winchester style threads

Mitchell Mauser No known interchange

Mossberg 500 & 535 Interchanges with Winchester, Weatherby, Browning Invector

Mossberg 835 and 935 Interchanges with 835 Mossberg style threads

Mossberg 9200 Interchanges with Mossberg 500 style threads

Mossberg Silver Reserve 12ga Interchanges with Ben/Ber threads

Mossberg Silver Reserve 20ga Interchanges with Huglu style threads

New England Interchanges with Winchester, Weatherby, Browning Invector & Mossberg 500 style threads

Remington Interchanges with Remington style threads

Remington Pro Bore Fits Model 105CTi, All Parker Models, New 1100 Competition, & Premier O/U

Remington Spartan Interchanges with Tru-Choke threads

Renato Gambo No known interchange

Rizzini USA, (cool.gif & (I) Interchanges with Verona LX Style threads

Rizzini (E) Current Production O/U Interchanges with Winchester style threads

Ruger Older Models Pre 1992 Interchanges with Winchester style threads (Short chokes)

Ruger SC Newer Models Interchanges with Ruger SC style threads (Long chokes)

Ruger (Side by Side) Gold Label No known interchange

Sako/Tikka 12ga Some Interchange with Invector Plus and some with Valmet threads Some Interchange with Invector Plus and some with Valmet threads

Savage Interchanges with Winchester and Mossberg 500 style threads

Savage 411 Interchanges with Tru Choke style threads

Savage 512 Interchanges with Ber/Ben standard thread

SIG Arms No known interchange

SIG Arms (Aurora) Interchanges with Verona LX

SIG Arms (SA3) No known interchange

SKB Short Style Interchanges with Winchester and Mossberg 500 style threads

SKB Competition Interchanges with SKB Competition style chokes

Smith and Wesson Old Version Interchanges with Winchester, Mossberg 500 and Browning

Invector style threads

Smith and Wesson Current version 2007 Interchanges with Ber/Ben standard thread

Stevens and Savage Model 411 Interchanges with Tru-Choke or Baikal style threads

Stoeger 2000 Semi Auto & P-350 Pump Interchanges with Beretta/Benelli threads

Stoeger 2000 Condor (O/U) Interchanges with Winchester style threads

Stoeger Luger (O/U) Interchanges with American Arms style threads

Stoeger Uplander (Side by Side) Interchanges with Winchester style threads

Traditions by Fausti Interchanges with American Arms style threads

Traditions Semi-Auto AIS2100 12gauge interchanges with Beretta style threads/20gauge -

No known interchange

Traditions Volo No known interchange

Thompson Center Interchanges with Winchester style threads

Tri-Star Phantom 411 and TR11 Interchanges with Rizzini style threads

Tri-Star Phantom Field & Model 380D Interchanges with Beretta style threads

Tri-Star Phantom HP No known interchange

Tri-Star Silver Series Interchanges with American Arms, Serial#4687037 or larger is Beretta/Benelli threads

Tri-Star Current 3 1/2" Semi Auto Interchanges with Crio Plus system

Tri Star Fab Arms No known interchange

Valmet Interchanges with Valmet threads

Verona LX O/U Interchanges with Verona LX threads

Verona 980 O/U No known interchange

Verona SX Semi Auto Models Interchanges with Verona SX threads

Weatherby Interchanges with Winchester, Mossberg 500 and Weatherby style threads

Winchester Interchanges with Winchester, Mossberg 500 Weatherby and Browning Invector style threads

Winchester Select Energy Interchanges with Browning Invector Plus

Winchester Super X2 and Supreme Interchanges with Browning Invector Plus style threads

Zafer 12ga Interchanges with Ber/Ben standard thread

Zoli No known interchange

Check any choke/gun combo with your gunsmith before using it!