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Jim P

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Discussion starter · #1 ·
I have seen it mentioned several times here about the older shotguns being choked about one size tighter than what there marked. I understand that this is because of the older guns were patterned with the older paper shells and wads and required tighter construction to pattern. Then when modern shells are shotin older guns they pattern quite a bit tighter. Ive had this experance with a 64 12ga super and a 72 bss 12 ga. Both guns were marked full and mod and the fulls were way tight and the mods were tighter than what i thought a full should be
I recently got a 20ga 1960 super marked skt/skt which is exactly what i wanted cus i plan on shooting skeet with it and maybe the odd quail.
I havent shot guis thing much but enough to know that im not breaking as many clays as i think i should and damn it seems to be choked tighter than skeet. Today i broke down and measured the barrels and i see why. It's plainly marked from the factory skt/skt and both barrels measure mod and mod or .610 and .610. Ive got a box of choke tubes carlsons and Briley and a couple mullers invectors and invector plus from guns I've owned and sold over the years and i measured all of them and all manufacturers both invector and pluses skeet
chokes all measure.625 and the improved cyl .620 and the mods measure.610
I read that most people don't want to 20ga guns marked skeet as its a undesirable choke for hunting and to those i say it may be worth a few dollars you can save buying a skt choked gun to measure the barrels and if you're gonna shoot modern ammo you may be buying a mod and mod choked gun
Now im trying to decide if i wanta send my barrels out and have them opened to Skt and skt as marked? Seems like its always something aint it?
 
Jim,

I'm no expert but I believe you can't just go by the diameter of the choke, you've got to measure the diameter of the bore to get the actual constriction. And of course we hear all of the time that it doesn't matter what's marked on the barrel, you've got to go to the pattern board to find out what you've got.

Sounds like a lot of work.
 
Discussion starter · #3 ·
Yea i need to do the pattern thing for sure. I haven't got a setup here to do that or i would have already done it. I bought one of the early 725s and got wound up in the ds choke thing and that about burned me out on the pattern thing but its bedn a few years now so i guess id better get set up to see whats going on with this 20ga
 
Discussion starter · #5 ·
Tijeras_Slim said:
Jim, I'm not a trap shooter, but there is a club in Belen that might have a pattern board.

http://www.shootata.com/Shoots,Clubs,St ... fault.aspx

On vintage A5's the bore diameter is usually marked underneath the barrel in the proof marks, son't know about Supers. It will be in millimeters.
Ill have to get my light and magnifying glass out and look the barrels over good
 
Discussion starter · #7 ·
Its kinda a quagmire the choke size thing. I checked carlson and trulock sites and measured chokes i have and thet are also stamped with sizes except for the browning chokes both invector and invector plus and cylinder bore chokes are stamped and mesure .630 skeets are .630 light mod has .012 construction and improved mod has .018 contrtuction and the browning mods arent stamped with a dimension but measure.610 but the barrel dimension may be different on the supers compared to the invector barrels. Im not sure how to find that information. I called briley today but got stuck in hold land. This thing sure seems to pattern awfully tight when shooting it. I got frustrated to other day missing clays with it and got my old 16ga out just to make sure i could still bust them. Got briley thin walls in that 16 with a skeet choke in it and i missed one with it. That old 16ga a5 is not eazy to miss with though.
 
Discussion starter · #8 ·
Slim I took that forearm off and it's stamped. I try to get pics but couldn't get anything that was readable at that size. On the left side by the ejector both barrels are stamped with the 2 stars and a s with a line struck thru the s vertically. With the forearm off on the rt side are all the normal proof stamps and on both barrels is a horse shoe looking thing with a 20 over a 75
On the left side only on the bottom barrel are the numbers 15.5 then a star followed by a horizontal s followed by 15.4
Do those markings mean anything in A-5 land?
Thanks for your help guys.
Jim
 
The larger should be the bore diameter 15.5 mm =.610, and the smaller the choke 15.4=.606, roughly a constriction of .004, right in the range for skeet. I guess it's time to hit the pattern board to see where it's shooting, and then what sort of patterns it throws.

Here's the best info on what all those marks mean (atleast for pre-WWII) Belgian guns, but much still applies.

viewtopic.php?f=53&t=216472&start=60
 
Discussion starter · #10 ·
So it seems that the bore diameter of the older guns must be smaller than that of the invector and invector plus barrels? The chat i see calls for a bore dia of .617 for a 20ga invector barrel and the carlson and Briley and turlock invector chokes i have are marked .630 cylinder and .625 skeet so the chart that im seeing the bore dia of .617 must be incorrect. It has a guys name on it, the person that published the chart is named Randy Wakeman? Seems iv heard that name before. I wonder if hes a reputable source? So my gun being stamped 15.5 or .610 makes the bore dia much smaller than that of the invector barrels. One thing that dosent make so ce is the .610 that i come up with for a choke dia when I measure the chokes? Mr Browning certainly did provide a bunch of us with hours of entertainment all thise years ago when he decided to make guns for a living!
 
The .610 figure is one I got from Jack O'Connor's "The Shotgun Book" which is of 50's vintage. Things have changed in terms of what constitutes exact bore diameter since then, but that was the standard when your gun was made.

Randy is reputable. You can probably find him up in the top Shotguns General forum, he posts under his own name. Ask him, I'm sure he'll be glad to help.
 
Discussion starter · #14 ·
I have all the faith in the world in mr wakemans information. I thought i would poke him with a stick this morning and see if he was paying attention to our discussion.
The next thing is going to be the pattering board and see just whats going on
 
I bought a BSS marked m/f after measuring bores I found .024 in right and .039 in left .Shooting confirmed the markings (tight and tighter).I sent it to Mike Orlen and had it opened up to.007 (improved skeet)and .015(light mod) for me it's the perfect chokes for local sporting clays.
 
Discussion starter · #16 ·
ShootingDad said:
I bought a BSS marked m/f after measuring bores I found .024 in right and .039 in left .Shooting confirmed the markings (tight and tighter).I sent it to Mike Orlen and had it opened up to.007 (improved skeet)and .015(light mod) for me it's the perfect chokes for local sporting clays.
I had one of those to. Never did pattern it, just shot the hell out of it. It was a turkey killing machine with 3"'BBs. Took it trap shooting one time and thr full barrel was about useless for my level of skill. Did ok with the mod but thing shot like it was a rifel insted of a shotgun! That was long before I'd ever heard anything bout steel shot causing barrel damage but I didn't ever notice any damage as a result.
 
Discussion starter · #17 ·
RandyWakeman said:
Jim P said:
So it seems that the bore diameter of the older guns must be smaller than that of the invector and invector plus barrels?
Image


Not necessarily, see above.
Hey Randy maybe you wouldn't mind helping me out trying to better understand this choke thing. The other day when I looked up the barrel dimension on this chart I only looked at the column giving the size of the invector barrel. I didn't go down to the fixed column and see that it lists both as being the same. It must be that the barrel size for 20ga and maybe for all gauges varied and they must have determined how much construction to put in for the choke they wanted after measuring the bore then putting the amount of choke it was to have then stamping the values on the barrel? My bore size is stamped .610 which is .007 off what the chart gives for fixed barrel. That makes since to me but what confused me is the value you have for invector is also .617 and i have 3 different manufacturers of invector chokes marked cylinder bore as the choke size and also stamped .630 and skeet marked that are stamped .625 which would make tge skeet chokes .008 larger than the bore of the barrel? I must be missing something somewhere. What are your thoughts?
Thanks, Jim
 
You cannot just measure the choke. It is constriction that counts. It is the difference between bore diameter and the smallest diameter at the choke. I have measured several 12 ga. supers from the 30's and 50's marked skeet and they all were .005 or less. There is a good deal of variation in bore diameter over the years. Chokes were cut on supers based on actual bore diameter, not some standard. By the way, do not accept what is stamped on the barrel. It often is the manufacturer's standard, not the actual diameter of the barrels used to make the gun.
Browning invector barrels have a reputation for having changed in diameter over the years and for different models, but Browning invector tubes are "one size fits all".
 
Discussion starter · #20 ·
lowgun said:
The real answer is "Learn to Shoot". Anyone who blames choke on their inability to hit clay birds needs to get some help. It is not the gun, it is the shooter who is the problem.
I'm so sorry there Mr Lowgun for taking time outta your busy day with my petty bs. Wont happen again so you can go on your merry way spreading cheer and goodwill and not have to be bothered by me anymore!
 
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