You won't know what it is unless you measure the bore. Patterns are performance-based, so unless you pattern the gun with the shells you use, you cannot know anything. Mismarked barrels and chokes are very common-- I see it constantly.

 

Hey Randy! I've been reading your stuff for years, thanks for the post. I plan to pattern it out of curiosity now, I want to compare it to my Fox 20 bore. Honestly when I got it I took it to the club and was dusting clays from the first box I put through it, so its been my go-to ever since, never really questioned it.

 

Theres a good chance that with good shells your cyl. choke may be pattering a wee bit tighter than marked but hey if your killin birds thats what counts.

 

I'm curious of how uncommon this setup is - its a 26" plain matted barrel. I once had a 28" vent rib 20 gauge and it didn't handle as well as this one with the short barrel. Up here in Canada they seem to be mostly full choke, or have polychokes installed.

 

I'm curious of

The cost of measuring the bore is usually nothing, from any competent gunsmith ot machine shop. It is a one time process as the bore isn't going to change. Most 26 inch SS's are IC, most 28 inch SS's are Mod. There isn't much use for a cylinder bore outside of slug barrels. Remember the old saga of the old 12 gauge and the dime? If the dime won't go in, well "That's a Full Choke, Son." It was always horse manure.

Mis-marked barrels from FN are common. It is still very, very common on factory screw chokes. We can all assume things, but the answer is easy to find.

 

In vintage guns choke markings are generally * full, ** mod, *** imp cyl.

 

Browning has their own choke marking convention. *** Is cylinder bore

 

30-ish yards with 1 1/8-5s will kill a lot of pointed and flushed birds.....and 5s will reach out with oomph farther than that, with a good strike or luck.

Choke matters but not a whole lot in most real world bird hunting near a bird dog's tail or nose and considering the multitude of factors in a making a good shot.
Pattern a bit at 40 yards, if you wish to determine if the choke designation is incorrectly marked.

Otherwise, enjoy the Auto 5.....and, it's shuffle & slam are not goofy.

I suspect a Cylinder designation is less common than any of the Big 3.....even in the days before message boards.

 

Yes I am hunting over a pointer so my shots are typically close, unless my wife goes in to flush and I take a passing shot. She's usually shooting a 20ga Superposed marked mod/full but which at some point has been opened up to IC/Mod or therabouts. Whoever did the work did a nice job as it patterns superbly. I think the forcing cones may have been lengthened as well. Only problem with that gun is I rarely get to shoot it, as she's usually got it in her hands....

So I wonder if I should ad this 20ga to the collection - its a 1963, IC choke marked (**-) and in decent shape with a bit of carrying wear. Same 26" plain barrel as my others.

I got hooked on the goofy cool old A5 when I inherited an early 16ga from a family friend. He had used that gun for everything from deer to ducks over the years, and it is about as worn out as any A5 I've ever handled. Something about it spoke to me, so I sought out that Sweet Sixteen. The worn out old one lives in the safe. I wish it could talk, it would have a hell of a lot of stories, knowing old Clifford.

 

A bird gun from the word "Go". Modern plastic wads will close up from cylinder to imp.

 

I think the choke marking shown is for a IC choke. And...my limited experience is that 16 gauge guns can pattern tight for the markings sometimes.

 

I have lots of bird guns, but two of my favorites are my 1966 Sweet 16 and my 1971 Magnum 20. I don't shoot 3 inch mags, just 2 3/4 field loads. I agree, when a bird folds at that "thwack-a-da" it's cool!

I also have a 1963 light 12 that I have yet to carry afield. It's genuinely a 98% gun, I was worried about scratching it, but honestly I don't believe in safe queens. I may need to remedy that!

 

Stop thinking and keep shooting birds

 

Nice wright up and photo's, take care.

 

I respect Randy's opinions but we disagree on this point. I don't measure my chokes, I measure my pattern.

If Faberelli comes up with a magic musket thing that patterns 50% at 40 yards, I am going to call that "Imp Cyl" no matter what the bore diameter is. I care what the bird sees, not my dial gauge.

	Constriction	Percent
Cylinder	.000	40% at 40 yds- 70 at 25 yds
Skeet 1	.005	45% at 40 yds- 75 at 25 yds
Imp Cyl	.010	50% at 40 yds
Skeet 2 (lite mod)	.015	55% at 40 yds
Modified	.020	60% at 40 yds
Imp Mod	.025	65% at 40 yds
Full	.030	70% at 40 yds
Extra Full	.040	73% at 40 yds
Turkey	.045 Plus	75% PLUS at 40 yds

(data from Trulock Chokes)

There is more to the final pattern than simple constriction. An abrupt step patterns differently than a long, smooth transition to the same exit bore. There are even stranger ways to focus the pellets.

With decent ammo, Open Choke isn't a joke for pheasants! I don't have a rangefinder, but 35 yards is a longer shot than I thought. Once I started pacing out to where the bird fell. It has to be an estimate, as my dog is already back, bird in his mouth.

 

I respect Randy's opinions but we disagree on this point. I don't measure my chokes, I measure my pattern.

I have no idea what you are talking about. OF COURSE, I shoot at paper and count pellets are varying ranges. Constriction is only a starting point, for you cannot compare soft lead to high-antimony lead to buffered lead to bismuth to steel to TSS without shooting and analyzing patterns.

 

And again, put the pellets where the target is, (be it clay, or animal, of fowl), and it will break, or die. It is just that simple, forget all the manufactures BS, the less you know the better off you are.


cdb

 

That list of constrictions is good, but for 12 gauge guns. Constriction amount will generally decrease a bit as bore gets smaller. For example, .010 is a good IC for a 12, but in a 20gauge .007-.008 is more like it. That's what Ralph Walker, Mike Orlen, etc. say and I tend to respect their opinions.

And I agree, these measurements are starting points, but what the pattern does at the target may be something completely different.

Just my .02

 

Above is with a Modified Trulock, Remington V3, and Winchester Diamond Grade Super Pheasant #5. Easily the best non-buffered lead pheasant load I've tried. I use a 16 inch diameter piece of acrylic over the paper and count pellets for pheasant loads. You need no Shoot'N C's for that.

Browning publishes:

How is Browning stating that their "Modified Choke" gives 35 - 65% patterns useful?

 

Speaking of tools, I agree. I couldn't justify the cost of a bona fide "shotgun bore gauge", but I found a set gauges that measure the inside of cylinders. I want to say it's an automotive thing but I honestly can't remember. They are spring loaded, you slip it inside from the muzzle, it expands, then you turn a locking screw which locks the expanded part in place, the you carefully slide it out the chamber end, and measure it with a micrometer. It's slow for sure, but the set also doesn't cost $400! I can deal with the inconvenience for the few times I actually want to measure a bore.

PS they're also about 8" long, so you can get a true bore measurement, and then the choke, and compute the actual constrictions.

 

You guys are going to have the OP measure, pattern, count pellets, tabulate and God knows what else and then he’s gonna start missing all those pheasants, sharpies, and Huns he’s been killing all these years.

 

I had the pleasure of shortening a Tristar TT-15 shotgun for my brother and fitting a recoil pad just in time for hunting season in a few weeks time. After adding weight to balance the gun, plus a clean and lube, I figured I’d measure the bore and the two chokes he had in it. Bottom barrel was .729 and top was .734. The IC choke was .714 and the IM .694. I took it to the pattern board to check POI for both barrels. What a pattern from that .040 constriction “Improved Mod” choke at 25 yards 😂

 

My 1966 Sweet 16 had a 26" Vent rib barrel choked modified.

 

Not a 16ga but here are a few of my pattern numbers to give you an idea of the kind of performance you might get from a true CYL choke.

A 12-gauge cylinder bore barrel or choke tube should have an effective distance out to about 25-30 yards, depending on the shot shell payload, pellet size, and target size. Here are a few of my 12-gauge cylinder choke pattern numbers at 30 yards to give you an idea of the kind of performance you might get from various loads.

Patterning results from a 12-gauge Citori with 28" Invector-plus barrels using Briley flush chokes (patterns average of five, 30" post-shot inscribed circle, yardage taped muzzle to target, and in-shell pellet count average of five).

30 YARDS (CYL .000” constriction from bore gauge)
Reload (STS, Red Dot) 2 ¾” 1 oz #8 lead (391 pellets) / pattern 219 (56%)
Win AA Extra-Lite 2 ¾” 1 oz #8 lead (393 pellets) / pattern 218 (55%)
Win AA Extra-Lite 2 ¾” 1 oz #7 ½ lead (344 pellets) / pattern 194 (56%)
Win AA Heavy 2 ¾” 1 1/8 oz #7 ½ lead (377 pellets) / pattern 202 (54%)
Rem Gun Club 2 ¾” 1 1/8 oz #7 ½ lead (375 pellets) / pattern 202 (54%)
Rem Premier STS 2 ¾” 1 1/8 oz #7 ½ lead (408 pellets) / pattern 238 (58%)
Rem Premier Nitro 2 ¾” 1 1/8 oz #7 ½ lead (420 pellets) / pattern 239 (57%)
Reload (STS, Green Dot) 2 ¾” 1 1/8 oz #7 ½ lead (402 pellets) / pattern 201 (50%)
Reload (STS, Green Dot) 2 ¾” 1 1/8 oz #6 lead (267 pellets) / pattern 147 (55%)
Fed Game-Shok 2 ¾” 1 ¼ oz #5 lead (224 pellets) / pattern 123 (55%)
Reload (WAACF, Unique) 2 ¾” 1 ¼ oz #5 lead (210 pellets) / pattern 125 (60%)
Win Super Pheasant 2 ¾” 1 3/8 oz #5 lead (234 pellets) / pattern 118 (50%)
Average pattern percentage of all loads / 55%

 

Light Modified - God's Constriction....only one that matters

 

A5ROCK,

Love your screen name!

Careful, mentioning God might bring on the mods!

But as long as you mention it, I might just slightly disagree. IC is God's constriction, the Holy Trinity being Skeet, IC, and Light Mod.

 

Mods...spelled " Control Freak " ......

 

I doubt that God or the supreme architect or whomever frets about choke constriction.....I wager the concern is on the decision to shoot...or not and then, concern is on the placement of an appropriate load.
I do know that a bird dog will be around, as more than a few of mine have been invited on the property.

 

I enjoyed your post!

 

why a 16 gauge would be made with Imp cyl choke is beyond me sweet sixteen were pure hunting guns not for military or SD. of course any shotgun can be used for SD

 

Afraid that reasoning went right by me......IC in a Sweet 16 or 16 gauge is bad because........ ???

 

A CYLINDER 16 gauge choke, according to Browning, is not a choke at all, but a .008 inch overbore.

 

thanks for the info Randy