Wingman Posted May 9, 2018 Report Share Posted May 9, 2018 Hi All I was explaining how choking works to my son and it occurred to me that my understanding has never actually been validated so can I run this by you guys to see if I have it correct please? Choke sizing is purely a constriction of the muzzle end of the barrel and is entirely relative to the bore diameter. For example my Perazzi has a bore size of 18.4mm stamped on the barrel whilst my Winchester Select is 18.5mm. So in practice although the difference is tiny a cylinder choke in the Perazzi would through a marginally tighter pattern than the Winchester. Of course all of this doesn't take into account shot size or wad type but I think the theory is correct? What do you think am I right? Quote Link to comment Share on other sites More sharing options...
seeker Posted May 9, 2018 Report Share Posted May 9, 2018 Once you get the idea that Choke is as choke does' rather than what is stamped on the side it's a wonderful world of variables. To further your point my last 12 threw a full 70% /40 yd pattern with 35 thou of construction. In my 28 bore it only takes a 23th to achieve the same. So you could reduce both to a percentage of the internal bore. Would this hold true for varying diameters? ... Maybe, But the devils in the variables. Quote Link to comment Share on other sites More sharing options...
Wingman Posted May 9, 2018 Author Report Share Posted May 9, 2018 I agree entirely, and that's what I was aiming to explain in other words it doesn't matter whats written on the choke tube the actual effect it has on pattern depends on many other variables. I have left Skeet and 1/4 in my Perazzi for about the last 12 months and don't have any problems breaking edge on clays at distance, probably due to the tighter bore diameter of the gun (maybe!). Son is using 1/4 and 1/2 in his 28 bore and is breaking clays nicely! Quote Link to comment Share on other sites More sharing options...
TIGHTCHOKE Posted May 9, 2018 Report Share Posted May 9, 2018 2 minutes ago, Wingman said: I agree entirely, and that's what I was aiming to explain in other words it doesn't matter whats written on the choke tube the actual effect it has on pattern depends on many other variables. I have left Skeet and 1/4 in my Perazzi for about the last 12 months and don't have any problems breaking edge on clays at distance, probably due to the tighter bore diameter of the gun (maybe!). Son is using 1/4 and 1/2 in his 28 bore and is breaking clays nicely! Get out on the pattern plate with your chosen cartridge and choke to see what actually happens and even then it is a 2 dimensional representation of what actually happens in the few micro-seconds betrween the trigger being pulled, the primer exploding and the powder igniting and sending the payload up the barrel and through the choke. Quote Link to comment Share on other sites More sharing options...
seeker Posted May 9, 2018 Report Share Posted May 9, 2018 9 minutes ago, Wingman said: Son is using ..... his 28 bore and is breaking clays nicely! Which must be the bottom line. Quote Link to comment Share on other sites More sharing options...
Wingman Posted May 9, 2018 Author Report Share Posted May 9, 2018 2 minutes ago, seeker said: Which must be the bottom line. Sure is and this was my roundabout way of trying to explain not to worry about the chokes that are in the gun! Best thing I ever did was buy him his own gun as he's now developed real interest in the sport.. Quote Link to comment Share on other sites More sharing options...
figgy Posted May 9, 2018 Report Share Posted May 9, 2018 Two ways of looking at choke. First is what a constriction patterns at a set distance. Second is the constriction compared to bore, old money is ten thou for every quarter of choke, 40" is full choke. In new money 1mm is full choke .25 mm is .25 constriction of choke. I always think its pattern that determines the choke. Quote Link to comment Share on other sites More sharing options...
Wingman Posted May 9, 2018 Author Report Share Posted May 9, 2018 Cheers figgy, I think taking the boy to a pattern plate would be interesting for him so might look into that soon! Quote Link to comment Share on other sites More sharing options...
Gunman Posted May 9, 2018 Report Share Posted May 9, 2018 Its all a load of codswallop . The choke is a now laid down percentage restriction of a bore size .Each bore size has its own defined restriction so a nominal 1/2 choke in a 12 bore is .020" but in a 20 its is .012". Again some countries will have a a variation on this . Different cartridges will pattern differently so it is a matter of finding one that suits the gun and you .This may take a little time but is worth the effort. In short chokes are useful device but there is so much rubbish talked about them that it actually gets in the way of shooting , people being convinced that they need this choke or that choke when in plain fact they need to spend more time actually learning to shoot the gun they have . Pre multi choke guns were bought and shot and many thousands of birds killed with no problem the user often not even aware of what if any choke the gun had .Many guns have been shot very successfully by owners believing the gun was bored to one choke set when in fact the chokes were totally different . For normal shooting 1/ & 1/2 or 1/4 & imp for driven are all that is really needed . Quote Link to comment Share on other sites More sharing options...
seeker Posted May 9, 2018 Report Share Posted May 9, 2018 Well now you've got a definitive answer to confirm your theory .... From Gunman's post above .... "The choke is a now laid down percentage restriction of a bore size. " And your sons got one of the ideal combos ...so on with the game ... Good luck. Quote Link to comment Share on other sites More sharing options...
Stonepark Posted May 9, 2018 Report Share Posted May 9, 2018 My 'play table' showing % bore reductions (at the bottom) for selected bores/guns. Note that choke sizes vary for different guns and also between choke manufacturers. First five columns are all 410, the remainder covering 12, 12, 20 and 8. Goes a long way to explain why my 410 OU would not perform with oem chokes. Quote Link to comment Share on other sites More sharing options...
wymberley Posted May 9, 2018 Report Share Posted May 9, 2018 3 hours ago, Wingman said: Hi All I was explaining how choking works to my son and it occurred to me that my understanding has never actually been validated so can I run this by you guys to see if I have it correct please? Choke sizing is purely a constriction of the muzzle end of the barrel and is entirely relative to the bore diameter. For example my Perazzi has a bore size of 18.4mm stamped on the barrel whilst my Winchester Select is 18.5mm. So in practice although the difference is tiny a cylinder choke in the Perazzi would through a marginally tighter pattern than the Winchester. Of course all of this doesn't take into account shot size or wad type but I think the theory is correct? What do you think am I right? To be honest, probably not. Any degree of choke in any gun will do exactly as it damned well pleases. The all too familiar standard UK choke tables look neat and tidy. All well and good until you get to TC and the (neat and tidy) 40%. It''s odds on that a truly bored TC barrel will throw something under that magical percentage and again, a barrel throwing the 40% will in all probability have a couple of points in it. If it was known precisely how choke works, then all chokes for any given performance would be machined identically. Quote Link to comment Share on other sites More sharing options...
williamwansbeck Posted May 9, 2018 Report Share Posted May 9, 2018 In the british guns 0.729 was 12 bore diameter and choke as a fraction of 40 thousands of an inch constriction at the muzzle ie 1/2 choke a 20 thou constriction,1/4 choke a 10 thou and so on. Its now known the taper and profile of the choke can cause nearly as much variation in pattern density and shot stringing as out and out choke value and this leads to various results from different manufacteurs,the modern multichoke guns can give very different results with after market chokes from teague or the like ,compared to the supplied chokes. The smaller bores have a standard amount of choke constriction according to the old british dimensions can not rember off hand but the proof houses have this stuff online i think Quote Link to comment Share on other sites More sharing options...
Wingman Posted May 9, 2018 Author Report Share Posted May 9, 2018 Now I am confused from this day forth I shall leave what’s in the gun alone and just enjoy shooting it! Quote Link to comment Share on other sites More sharing options...
welshwarrior Posted May 10, 2018 Report Share Posted May 10, 2018 The writing is a modern thing doesn’t matter what you stamp on choke or barrel it’s the pattern the combination actually produce with a cartridge on the pattern plate. Modern live is to fast and multi chokes to much cartridge choice has lead to a rounding off of corners a calculation that give about the right right answer with most cartridge based or bore and constriction. Quote Link to comment Share on other sites More sharing options...
wymberley Posted May 10, 2018 Report Share Posted May 10, 2018 16 hours ago, Wingman said: Now I am confused from this day forth I shall leave what’s in the gun alone and just enjoy shooting it! Way to go. However and as you've already hinted, it might just pay to take the existing combination to the pattern plate for a proper check. This just in case your existing cartridge is ceased production, amended or whatever as is often the case now and so that you know what to look for in a replacement. Quote Link to comment Share on other sites More sharing options...
Vince Green Posted May 14, 2018 Report Share Posted May 14, 2018 Don't forget also that shot size can have an effect too. Theoretically the effect of choke becomes more pronounced with bigger shot. The reasons are complicated but a simplistic answer is because with bigger shot a higher percentage of the charge comes into contact with the choke. There are so many other things though I can't see anybody worrying about it. It becomes a problem with very big shot in full choke wildfowling guns when it can actually cause the pattern to cartwheel. The pattern plate has the final word though Quote Link to comment Share on other sites More sharing options...
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