doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Target-gun bbls - what's the latest thinking?

What is the latest thinking on the best way to tune a set of bbls for target shooting?

Are the serious guys shooting over bored OUs?

Do they do anything to tweak the forcing cones?

What about the chokes? Are they longer, with a more gradual taper?

Just wondering.

Thanks for the help.

OWD

Not much overboring. The "pros" shoot whatever their sponsor mfg. gives them. Most are already .735-.740. Some may have a little forcing cone work done. Chokes and choke tubes vary from fixed mod/imp mod/light/full for guys like Wendell Cherry to whatever screw-in mfg sponsors them.

All the rest of us are somewhere in between. I'm in AA and shoot 1500-2500 registedres targets/tournaments a year, and 6000-8000 practice targets a year, and I shoot a 32" DT-10 with Trulock chokes. No ports, no adj comb. A little added weight under the forend, it weighs 8lbs. 10 oz.

Works for me. http://www.winscoreonline.com/view_resul...mp;class_id=All
JR

John's on the pulse of what the "serious guys" are shooting. I don't think many "tune" their guns, as far as over boring or forcing cones. The truth is that most of the top comp gun manufacturers, P guns, K guns, Beretta, CZ, have worked this out to the point that what wins shoots is skill. Every top shooter is shooting a gun capable of winning and none are exactly the same. Fact is that the top guns occasionally change gun sponsors, and still win. It has more to do with which company offers the sweetest deal than which gun is the "best".

Very few of the top guns today are habitual "choke changers". I do not mean that they never change chokes, some do when faced with a very "out of the box" presentation, such as a 10 yard fast rabbit, but many very seldom change chokes, preferring to shoot fairly tight chokes all the time. Do the pros really "believe" in the brand choke they are shooting? Sure they do. Confidence is a huge part of the game. But any precision manufactured choke tube will win. Hell, it doesn't even require screw chokes at all. I shoot a fixed .023" bottom and a .020" top in my MX-8, and do not feel handicapped at all. I think I hold my own pretty well, when you put in perspective the number of registered targets I shoot a year.

SRH

Great shooting John!!!!

Interesting. Thanks.

OWD

Stan, You must be shooting some spreaders then with those tight chokes at regular sporting? What brand spreaders do you like? Do you use that Perazzi for FITASC or do you go to tighter chokes?

Gregg, overbored barrels are not needed by any competition shooter. Nor are long forcing cones. The bottom line is how the pattern looks on the pattern board. What discipline are you considering participating in?

8Bore-

I'm just interested, that's all - and your mention of the "...how the pattern looks on the pattern board..." is why.

I'm interested in learning the latest thinking on how to achieve the best patterns possible, and I figured competitive target shooters would know the most about this.

These days, does this have less to do with bbls and more to do with loads & shot cups?

Thanks,

OWD

OWD; Take a look at www.jimeyster.com and read all about it. He discusses forcing cones, choke angle and boring of barrels in a lot of detail. Much of this work was done when almost all 12 bores were .727". Now, manufacturers are producing their products at .740 because supposedly they pattern better and less perceived recoil. Kolar even made .750" barrels for awhile. The guys I know that have them really like them because perceived recoil is apparently very low. I've heard Kolar quit making the .750 because in order to keep weight down, the barrels were thin and dented easily. I haven't heard that from Rags at Kolar, but just shooters in the know. Frankly, if guns fit, I can't tell much difference in perceived recoil in .727 vs .737 or .740. I shot a .750 once and it still seemed to kick.

OK. Thanks. I will.

I don't understand how bigger bores could have an impact on recoil, though.

The bore size doesn't change the amount of force the load is pushing back with.

Of course, perceptions are all in the head!

OWD

I had a .750 bore Kolar for a while. Didn't pattern great and the gun just didn't fit. definitely not a light weight. Dropped out of M to AA. I had previously shot a Beretta Trap models. Now I shoot a 32" high rib CG. NO PORTS!!!! LM&M never leave the barrels. I haven't had to use spreaders lately due to the long range rabbits that are becoming prevalent. I've notched a few punches and working my way back to M....I hope .

OWD,
I think bore size would effect weight, which would effect recoil.
If you have two seperate tubes of equal wall thickness,but slightly different bore size, the larger one will weigh more,as there is slightly more wall metal...I think that's right...?
franc

Barrel "tuning" is my pet peeve and just so much bullshiiit. Anyone thinks they can make a Perazzi (or similar) barrel "better" is living in a fantasy land. Like Neil Winston (google for info) commented - if a barrel "tuner" could make a barrel shoot like crap and then "fix" it so it shot like prize winner he'd believe the hype. There were, big surprise, no takers. And there is no empirical data to support ANY claims about ports and big bores - just hype and "it feels better" (since I pounded $1k into the work and it better be cuz I ain't gonna admit it's not) kinda reports.

I can understand to a point about opening chokes that are too tight for a particular game. Mutilating a primo barrel with screw-ins or ports should be criminalized. If the gun isn't what you want then get one that is and don't fook up something that may be irreplaceable.

Of course I'm only referring to quality guns and you can do anything you like to some junker.

JMO of course and I could GAF if you believe the BS

have another day
Dr.WtS

Kolar has indeed gone to 740 'Light Contour' barrels.
I recently had a 34" Unsingle Trap barrel fitted to my SC gun at the factory.
I was concerned about the length but it's just great!
Still weighs slightly more than my 28" old style SC barrels.
I also purchased a set of Titanium choke tubes just because!
Rags, Jeff et al really know competition shotguns.
You can walk in and have most any service performed while you wait.
Barrels took two weeks with shooting to POI when I picked up the gun.

Kolars have less recoil because most of them weigh 9 pounds or more.
I do believe that long forcing cones, somewhat bigger bores and long choke taper do contribute to better patterns, but each of these things only provide a tiny improvement. Lots of excellent competitors have their barrels "Eysterized" no matter whose gun they are shooting. I consider my Perazzi with 0.740 bores, long cones and factory original 6.5" fixed chokes to be the ultimate in barrel performance. For serious competition it gets fed B&P ammo - this way I have zero excuses and all the confidence in the world in my equipment.
Regards,
Jeff

Mr Sane-

What do you think about the info posted here:

http://www.winscoreonline.com/view_resul...mp;class_id=All

I don't think tuning your bbls is going to turn a lousy shooter into a pro. A lousy shooter is a lousy shooter - regardless of the gun.

But if you're competing at top levels, some modifications may give you the tiny edge you need to win.

OWD

I don't think any tiny modification will change the success of any shooter, not matter how high on the pole he may be. If you have hit the bird with a common shotgun, your will hit it with a high tech shotgun. If you hit it with a top of the line, high tech shotgun, you will have hit it with a common shotgun. Make sure your shotgun shoots to "Point of Aim". That's all you need.

x1

A.J. Aubrey had it all 'figerd out in 1908, at least that's what the Sears catalog said
"Shooting qualities - As before explained, the shooting qualities of these guns are unequaled for long distance killing, long range shooting, for penetration, pattern or target. Both barrels are full choke bore, so firmly constructed that unlike other guns, there is no recoil or kicking. That which in other guns goes into recoil in the A J Aubrey gun goes to give greater force to the shot."

Hi buzz,

I do not shoot spreaders. I admit I do this thing a little differently, sporting I mean, but I started shooting this gun with these chokes about 6-7 years ago, and never looked back. My scores increased until I punched into M class in 2010, although the last few punches to put me there were gained with my BSS at the S x S event at the 2010 U. S. Open. I on;y shot a couple small registered shoots in 2014, so they bumped me back down to AA, which suited me to a "T". I have a confidence level that is hard to explain when shooting these fixed chokes. I just know that there is nothing they will throw that I cannot crush with them. As to the close stuff ............. it just goes away in a puff of dust. I thought, when I started shooting these tight fixed chokes, that I might lose some close rabbits or crossers because of them, but that has not been the case. When the other guys on my squad are deciding how open a choke they can get by with, on a particular presentation, and changing them, I am thinking about how I will set up on it, whether or not I will begin my gun moving at sight of the bird or when I hear the trap throw, what the line is, what the speed is, where is the best place to break each bird in the pair, stuff like that. Maybe they are smarter than me, and are able to process more information in a brief time than me, but I just shoot higher scores when I'm not fiddling with choke tubes. YMMV.

I have settled into a groove that is working for me. I cannot shoot many registered targets a year. I love to shoot S x S events when possible, and doing that cuts into my total amount of big shoots I can shoot a year. But, what I am doing is working for me, I think, as evidenced by a shoot I was able to attend on Friday only recently. It was the NWTF "Turkey Shoot", a big sporting clays event with lots of side games that happens in August each year. I have not been to a big shoot the whole year, until that one. Because I was only able to be there on Friday I shot the competition 5-Stand, the Prelim, and the S x S event. I won AA class in the 5-Stand, won Veteran's concurrent in the 5-Stand, and won AA class in the S x S event. My score in the 5-Stand tied the second highest for the whole event, a 45x50. 395 entrants in the shoot.

http://app.scoringpro.com/public/awardssummary.aspx?enc=936BbrRl5E4imlu/L52CdZ9kBZZ7S4I43+g3Mlx7kv4=

Tight chokes work for me, and several top guns as well. King George included.

SRH

Oh, I forgot. I hardly ever shoot FITASC. I can't shoot everything at a big shoot without stretching myself too thin, and I really like the Main Event, the Five Stand, the Make-A-Break, and the Long Bird comps the best, and try to concentrate on them.

SRH

You'd think as long as Gunmakers have been reducing the kick & turning it into useful work that guns would be pulling away from us by now, instead of setting Back. All this still brings to mind the words of the late Julian S Hatcher when he said there are a lot of things which sound good if you say them "Real Fast" which just don't stand up to scrutiny. Last I heard Recoil was still determined by 3 factors.
Total weight of the ejecta, total velocity of same & total weight of the gun.

Conservation of momentum requires that the gun have a rearward velocity proportional by the ejecta weight vs the gun weight to the forward velocity of the ejecta. That requires that the gun experience an acceleration proportional to any experienced by the ejecta. Total recoil of the gun is easy to determine for both momentum and kinetic energy. The fly in the ointment is that we have, so far, no way to know what the shooter actually senses. It could be peak momentum, peak energy, displacement, acceleration, etc. It is based on pressure only in that pressure is causing acceleration, not pushing back on the gun.

All involved in this discussion need to read "Sporting Shotgun Performance" by Dr. Andrew Jones. Constriction was about it for choke effect. The gem of his book is, however, a computerized method for pattern reading and analysis, statistically valid analysis. To my knowledge, this is a real first. Anyone taking the time and effort to shoot patterns owes it to himself to read this book.

DDA

A big plus on Andrew Jones book. It dissolves some long held myths and confirms that shooting technique is more important than messing around with chokes and such.

Just tried to buy the book -- $49.95 on Amazon! No way.

So what's the synopsis?

And please dumb it down a bit. I was an English major.

Thanks

OWD

On a link from Dr Andrews' site yo can get a fair number of pages from his book on line.

Synopsis is that shotgun patterns seem to follow the law of Gaussian distribution which means that roughly 60 per cent of the shot is in the central 1/3 of the max spread of the pattern. This is observed in all chokes, spreads and distances. Ergo you try to put the center of your pattern on the target and forget the fancy stuff, in other words technique is paramount, ballistics not so much.

This was a very rough synopsis.

Have had a choke epiphany recently with a 1906 damascus barrel OE 16g Smith with barrels cut from 30" to 29". Hunter Arms 16g chokes were about 1 1/2" and indeed the choke constriction is now slightly less than 1/2"; .005" right and .010" left and patterns a nice IC and Mod. How can that be?
On my 6th case of RST 3/4 oz. at 1100 fps skeet loads.

Choke specifications from the L C Smith Plans & Specifications book show them in 12ga having a choke cone of 1 9/16" in length follow by a parallel section of 1" length at the muzzle. Specs are not given for the 16ga but likely similar. thus cutting the barrel by 1" would do little except remove the parallel, the constriction in the form of a "Short" taper choke would remain.
Most companies who used the taper choke such as Lefever & Fox etc used a much longer taper but no parallel at all. Full choke in my Lefevers generally runs around 4" in length.
This drawing is not dated so perhaps early LC's had a different configuration. Whatever the case my thinking is sounds like very useful patterns, don't fret it, just enjoy them.

I use screw chokes about as often as Stan does. If I need different chokes for a different course, I shoot a different gun or change chokes at the beginning of the shoot and leave them there. My biggest win in sporting clays was when I entered the course with my .410 equipped with modified and tight modified choke tubes. I had a handful of 3" shells in my bag for the really long shots. At that event, no ammo restrictions were in place in the .410 event. I ran the birds on the first station and was so ecstatic over my success that I forgot I had choke tubes or 3" shells. I won the .410 event overall with tight chokes and 2 1/2" shells and never looked back. I won't identify the shoot, but the competition was pretty rough for a non competitor like me.

You are correct Miller, for 12g. To be clear, I measured the bore and constriction using a Stan Baker gauge to which I affixed a fabric tape measure.

About 2008 I issued a request on the 16g site for 16g choke measurements and a number of respondents provided data for Parker, Fox, Baker, Ithaca, and Smith guns. Almost all had a choke length of 1 1/2 to 2 inches with a very short parallel section at the muzzle.

The pre-1913 16g Smiths that I have owned; 1911 OOE, 1906 2E, 1906 OE, all had about 1 1/2" choke lengths.

16g Parker guns made from 1891 to 1927 with chokes from .002 to .040 all had a choke length of 1 1/2" to 2". I think Dave Miles and Austin Hogan provided the data.

Fox 16g doubles made in 28', 33', and 37' (? measured by Dave Noreen) were found to have chokes about 3 1/2 inches long in the tighter choked barrels BUT a 1936' 32-inch barrel A-grade had full chokes of only 2 1/2 inches.

Drew has just clarified that, regardless of maker, choke length is variable among and within makers. I kind of knew that considering the number of Fox and Parker factory orders I have seen where chokes are modified both tighter and looser and barrels cut, yes, barrels cut, to result in the desired choke.

ODW, read the following with an open mind as a bunch of OWT's don't pass muster in the light of scientific evidence. Jones based his conclusions on some 2500 patterns shot in groups of 10 per gun/load/choke. His early work showed that patterns are so variable that samples of less than 10 are likely, very likely to give false data. The most impressive part of his work is methodology to capture patterns with digital photos, feed the photos to a computer, and software to give statistically valid analysis. For scientific purposes, his is the only "good" data we have.

Synoposis: OWT's investigated.

Increasing the velocity of the shot tends to give wider patterns (Largely false)

Fixed choke guns can give the benefit of tighter patterns by using larger sized shot (False)

Plastic wads are the greatest advance since the invention of choke boring (True for trap, False for most other shooting)

Boring barrels beyond nominal improves the quality of the pattern (Largely false)

Soft shot gives wider patterns (True, but largely irrelevant for most shooters)

Very tight chokes lead to blown patterns or overly "Hot" centers (False)

A taper-parallel choke gives the best patterns (False)

Some combination of gun/load gives more even patterns (False)

Steel shot gives tighter patterns than lead (False for UK #7.5)

Heavishot gives tighter patterns than lead (False)

Short shot-columns give better patterns (False for typical weights of shot)

Every gun is a law unto itself (False until someone tests every gun)

Multiple pellet strikes are required to break a clay target (False)

There is much more, but it is some heavireading!

DDA

Don, you should've started another thread with that post, thirteen of them in fact!

We have discussed many of them in previous threads and I have decided that some of the above statements are correct only when stated exactly as they are, but that they convey a different meaning to the average joe (read, non-engineer). A slight change in the wording changes the entire scope of meaning, i.e. "Multiple pellet strikes are required to break a clay target". That is false only because the author proved that he COULD break a clay target at times with one single pellet. It does NOT mean that one pellet will always break a clay target, that one pellet will probably break a clay target, or even that one pellet stands a good chance of breaking a clay target. I have, and can at any time, walk out on a clays course and pick up a sackful of clay targets that have as many as four pellet holes through them, that are otherwise unbroken. That particular statement is useless to most clay target shooters, IMO.

This is just an example of how vague several of Jones' statements are regarding patterns and their effect(s), and their causes.

SRH

So it sounds like the take away here is: It's the shooter, not the gun.

Thanks for all the input.

OWD

Great reply to Don's list Stan. Very well stated.
JR

Stan, you are right about the exact language. However, OWD wanted a synopsis and I think this is a fair one for an English major.

As you have shown, even multiple hits, even as many as four, don't assure a broken target. Nor, does one hit assure a broken target. But, big butt, single hits can break a target. The research was for predicting probabilities of broken targets so patterns can be associated with scores and aiming error.

DDA

Pretty much, IMO.

I'd say that the shooter is the biggest contributing factor to breaking birds consistently, and at a high percentage. The fit of the gun is important, using an appropriate load is important, using enough choke is important, and I think for most of us mere mortals, using a heavy enough gun to help attenuate recoil is important.

SRH

Hi, John. Assuming you are primarily agreeing on the single pellet target breakage, consider the following. Are you aware of any other research on target breakage other than collecting unbroken targets and assessing hits? I'm not. Far as I know, Jones's work is unique for scientific determination of what is required to break targets.

As Jones notes in the book, there are many factors involved in the dynamics of whether the target breaks of not. There are zones of the target that are robust to a pellet strike, others that the pellet can penetrate with full expenditure of it energy, and still others that the pellet can penetrate without expenditure of full energy. Further, the angle at which the pellet strikes is important to the amount of energy imparted to the clay; penetration vs glancing.

When the clay is struck by a pellet imparting sufficient energy, a fracture initiates at the point of impact and spreads across the clay. Clays are actually very strong, but brittle. The spin of the target is exactly the force that tends to grow the fracture. The extreme example of this is the target that more of less falls in half in a clearly discernible time lag after the shot.

We have all seen targets emit a puff of dust and proceed merrily on their ways. Likewise, we have seen targets shed the proverbial visible chip, break in half or three pieces. These are more likely to be single pellet events than multi-pellet events. Only more likely, not exclusively.

The foregoing may not seem useful to the shooter. However, I'll give an example of how it has affected me. I no longer say such lines as, "You must have been behind that one since the chip came off the back edge." I now know that I have no idea how much rotation the target had between impact and fracture growth to chip shed. If the target had half a rotation, I would be 100% wrong.

Jones did not totally solve all shotgun pattern questions, but he did give us a wonderful set of data to build upon.

I have two suggestions: #1. read the book, and #2. don't bother shooting patterns unless you are going to do Jones's analysis.

I hope no one is offended. This is meant only as discussion.

DDA

Spoken like an engineer (and that is a compliment). To paraphrase Drew Hause's tag line "More data, less talk."

He may have a certain perspective on this issue, but Jim Eyster is extremely knowledgeable about target gun performance and is very generous with his time if you call with questions. His approach is data-driven and does not simply rely on standard modifications like lengthening forcing cones.

Like I mentioned before - if you are gonna be doing patterns and making grand statements from your "data" then you really need to read the methodology that Neil Winston uses. The BS Eliminator.

People like Eyster and the like in particular should be reading that.

thinking something doesn't make it real

believing something doesn't make it true

have another day
Dr.WtS

Eyster

For those of you who like to delve deep into the mysteries of one-pellet strikes, this thread has an in-depth discussion involving Neil Winston and Dr. AC Jones on that topic:
TS.com