Gentlemen,

I read this forum virtually every day. I enjoy shotguns very much especially doubles and the faithful Winchester Model 12, 42 and Browning A-5. I cannot count the thousands of rounds fired at clays and live birds that have been spent by my hand during my short lifetime of 55 years, although, that could be a result of my poor upbringing and lack of education.

One thing continues to perplex me about this sport that we all love. Perhaps this has been covered before, and if so, please forgive me. Why is the balance point of a double so important at the hingepin, when the hinge pin varies in it's location so much from model to model, maker to maker. It is different in relationship to the breechface, trigger, and butt of the stock. It would seem to me to be irrelevent. After all the discussions that have taken place since the utilization of the hinge pin on double guns, I would have thought by now, we, as a group, that critique everything we fondle and shoot, would have come up with some better method of describing technically rather than by metes and bounds, a quality that so many find to be so critical to our success in wingshooting. Bear in mind, I am not offering an answer! But, am still pondering the question as to the hingepin's importance.

Respectfully,
Hairy

The most important consideration, in gun balance, is that the most weight be "between" the hands.It has sort of evolved that just ahead of the pin is where the gun should balance.
I think it boils down to just what feels comfortable and this point makes the gun do that.
Stand by for an academic comment on the physics of this and pay very close attention (:}).
Best,
John

Hairy, for me the preferred balance point of a heavy, long barrelled gun is in front of the hinge pin while on a short barreled gun it is at the hinge pin. I would guess that this is an opinion question rather than established fact. Peter

What John said!
Yes, there are more precise and scientific ways of doing it, but the hingepin is an easily identified point of reference which is probably generally nearest the actual correct balance point.
We may await Rocketman's contribution; he has been empirically measuring this stuff.
RG

I'm inclined to go along with hairy on this. It really doesn't take a rocket scientist to figure that if you take for instance a box lock with a short bar, as many of them have, having the same apparent balance as a side-lock with a long bar, also common, the balance point is "NOT" going to be at the same place in relation to the hinge pin.
The hinge pin's function is as a fulcrum for the bbls to pivot upon when opening & closing the gun & has little revelence to point of balance, just "Coincidently" happens to be "Nearby".

I've seen some of the local cognoscenti speak of balance point measured from the trigger. Makes a ton of sense to me.

The "how and what" of shotgun dynamics is irresistable. My brother's a real engineer (as apposed to a sanitary or systems engineer )and we BS'ed late one night about how to non-destructively measure sectional weights of guns - looking for the weight distribution that makes a sweet swinging gun. Something that could be lined up next to Rocketman's inertia measuring machine at the table. He thought the only way to do would be a liquid displacement in a very big graduated cylinder. We couldn't come up with a liquid that would be acceptable to gunmen. Scotch would foul up the oil finishes.

The point of reference used to tell the stocker where to balance the gun is the standing breech.

Hang a loop of cord from a hook and suspend the gun. When the gun is steady, measure from the cord to the standing breech.

The balance point for any particular gun depends upon the intended use and the desire of the shooter.
danc

It strikes me rather odd that a balnce point is used as a reference, when there is no fulcrum. The gun is suspended by two points and rests upon another. It would seem that a gun could balance on the hingepin and weight in at 65 pounds and be virtually useless in the field. Would not weight distribution or a ratio thereof at the points the gun is held when in a shooting posture better describe what we want in what has been called balance? And, would that not change from shooter to shooter of the same gun depending upon their own personal shooting style?

Hairy

Of course. I once had the displeasure of being made to shoot a Beretta 391 Sport ("Just try it out!") that had a barrel weight AND a stock weight added. Go figure... the guy buys a lightweight gun and then proceeds to make it into a heavy gun by adding weight, but of course the weight he added is in the ends.

It wouldn't move. Remember playing with a gyroscope toy? Same feel. Rigidity in space, they call it...

What you post is true. That is the reason that I, and others, think that the weight of the gun must be balanced between the hands.
It really does not matter the weight of the gun if that is the case.
I suppose we have to agree on what balance means. I don't think it is very different with various shooters but is greatly different in what these different men perceive as a good feeling gun. A wand may be a 2x4 to different men. Gun fit is the key word here.
It seems to me that if a gun fits the shooter well and he feels that he has the control of it, the weight will be between his hands and it will simply be a natural thing to swing it and shoot well.
It is probably a coincidence that the balance point is near the pin.
Just thoughts.:}
Best,
John

"Why is the balance point of a double so important at the hingepin"

Because,,, if the gun does not balance on the hinge-pin it will fall off the top your shoulder when trying to use two hands.

Mark,
Now that's a sensible comment...thanks.

Sharp,

I'm being very serious. We can talk all about why and why not but when you're in the field those things are very important, at least to me. A gun that balances just a mere inch forward of the hinge pin will not balance on your shoulder or the crook of your arm.

Three or four years ago the owner of a range nearby handed me her gun. It was a Krieghoff O/U and she said mount the gun and tell me what you think. I responded that it was extemely light and very fast. I'll be darned if I understand how this 8 1/2 lb. gun could have felt that light but I think this talks to what you are discussing.

Bingo, builder !!!!!
Best,
John

Balance is a separate thing to "pointability". I supect that often the two are used interchangeably when they're not.
Pointability is that quality you get with a gun where the weight is not just balanced but concentrated between the hands by light barrels and stocking, and is very much to do with inertia. That's why guns with the same overall weight and dimensions can still feel so vitally different - one can be a nearly living wand which dances surely to the shoulder and chases targets of its own volition, and another a lump of 4x2.
RG

From my research, we need four numbers to sum up a gun's dynamics, its handling fingerprint, if you will. Weight is the most fundamental parameter. It determines the effort required to carry, lift, and hold the gun; further it determines recoil attenuation. Beyond lift, all other movement of the gun is changing the direction it is pointing.

Swing is the movement that changes the direction the gun points. The effort required for swing is measured from teeter-totter balance point and moment of inertia at the teeter-totter balance point.

Teeter-totter balance, along with hand placement, tells you how much of the gun's weight is carried by each hand. I measure from the balance point to the (front) trigger because the trigger is the one point on the gun you must touch to shoot. The balance to trigger measurement allows comparisons of all types of guns, even those that don't have hinge pins. You can use any point of reference you want, but you will always come back to relating the balance point to hand placement if you are going to do anything with it. There is no perfect balance point, only personal preference.

The amount of muscle effort needed to make the gun swing when held between the hands is measured by moment of inertia at the balance point. MOI is a measure of weight distribution. When the gun is mounted to the shoulder, the swing axis can be considered to be the butt and can be calculated. Preference for swing is purely a personal decision; some like wands and others pigs on snow shovels.

So, if we know weight, balance point, swing effort at the balance point and swing effort at the butt we pretty well know how the gun handles. Trying to tell someone else what handling fingerprint he should like or use is much like telling what stock fit dimensions he should use. Shooters must realize that what they shoot best and what they enjoy shooting most may well be two entirely different things.

Thank you all so very much for enlightening me on this subject. I really appreciate it.

I hope everyone on the board has a Happy Thanksgiving & Good Hunting!

Hairy

There is an excellent article in Gough Thomas book "Shotguns and cartridges" on gun balance.
He refers to it as a guns "moment of Inertia" and actually measures it on a cradle to come up with a figure.

GDU

GDU - balance and moment of inertia are different things. Balance is the point where the gun stays level teeter-totter fashion when placed across an edge or round fulcrum. I reference it to the (front trigger) as the best point to make direct comparisons from gun to gun; not the only reference point possible, but the best. Moment of inertia is a different attribute and I measure it with a small machine I have constructed.

Weight is a measure of effort to lift and hold. Balance is a measure of how the effort is divided between the two hands. Moment of inertia is a measure of the effort required to swing the gun.

Rocketman,

Does the MOI change with the relationship of the gun to horizontal, or, it's position to the pull of gravity? Too, how about some pictures of your machine to measure it?

Hairy

Ever lift a truely great gamegun and question it's balance - think the makers were intune with this much more than we.

Some interesting comments. Rocketman's approach is the one and only truly good engineering approach I've seen to quantifying the gun's characteristics. Lowell's comment gives praise to those great gunmakers of the past that emperically developed some really great handling guns. John Mann's comments acknowledge that men are all built differently and thus a given gun's characteristics will be percieved differently by different people.

Builder, I think what you were experiencing with that K80 was that the MOI was relatively low for the gun weight. That could be due to a short stock or short/light barrels or both. Two identical guns but for their LOP will have different MOI's and therefore different "feel"/"swing weight"/"livelyness" or whatever the favorite buzz word is.

One thing I've concluded for myself; I like different MOI/overall weight guns for different applications. What produces the best shooting is not necessarily what I want to carry up and down steep hills all day long.

Hairy Clipper et al:
Shooting Sportsman magazine, Sep/Oct 2001, starting page 72, "Measuring MOI' by Don Amos. This is a major article supported with good pictures, dealing with Rocketman's updated/upgraded/up-engineered MOI measuring tool. THE early "MOI" measuring tool and explanation is shown in Gough Thomas Gun Book...but Rocketman carries the idea and tool/device design far forward.
Shooting Sportsman magazine, Sep/Oct 2002, page 18, "Reproducing Gough Thomas's Device" by Thomas Hamernik. The title says it all....a one page article with a picture of the device.
Unstated in this thread,(so far), is that Rocketman has kept a record of the many guns he has "spun", which gives his words and comments just that much more value.
Hope this helps.

Ian,

I do not have those issues in the archives, but, will try to find them. They sound like great articles.

Hairy

LG - To answer your question directly, "Yes." The Brit makers worked out good patterns for most shooting purposes. However, they worked them out for their most usual clients. They built to weight and balance. MOI was unknown until Thomas showed the application. So, whatever was done by gunmakes before Thomas, was done on intuition. The kicker for me is that there is little physical commonality between me and your basic Brit now and much less 100 years ago. Since I buy used, not bespoke, I have to deal with guns made for smaller people. So, yes, I question the handling of all guns, Brit best included, that come within my grasp.

HC - MOI is the same number in the pitch (up and down) and yaw (side to side) axis. It would be different in the roll axis, but we don't have a movement of the gun that involves roll, so I don't measure it. I'm having trouble with posting a photo of my MOI machine; I'll post one as soon as I can figure out what is wrong. It is small and simple. The gun turns a timed 360 degrees from a standing start under constant torque. That allows a calibrated MOI to be determined from the time.

Rocketman,

I know what you mean about "physical commonality" my maternal grandmother whose family came from Scotland was about 4'10". There were chairs in her home that looked like something for a child. I, however, am 6'4" and weigh in at 345 pounds. I have rather large hands. So much so that I had to have the 'nose' of the comb moved back on my Thomas Turner & Son SXS in order to properly grip the wrist of the stock, get the safety off and get to the rear trigger. For a while I had a double barrel single shot. Cars do not fit well either, or basements of old houses, etc.

Hairy

How they fit your body type is a different story, but right off the high end used gun rack, the really good ones are most likely perfectly balanced no matter who they were made for. I have yet to heft a nice gamegun and think it very hoggish.

LG - my point is that there is no "perfectly balanced;" "balance" in this case seems to be used as a summation for handling characteristics. Most now agree that there is no such thing as "perfect stock dimensions." A given set of stock dimensions and handling finerprint can be a very close fit for a number of people, but not in a generalized way for the entire population of shooters. Many/most people find the light weight, center balance, and low swing effort of a typical game gun to be delightful. However, "delightful" is far from "perfect." Once a shooter has gathered enough information on his own preferences for handling, most will find the the delightful game gun fits a fairly narrow range of shooting activity. Sorry, but I do not believe that game gun handling is "the answer."

Gun folklore, tradition, beliefs, etc., all are deeply rooted. Some deeply rooted in partial accuracies, or accurate only under certain circumstances, or rooted in total inaccuracies.

For me and my varied shooting activities, I find I like guns that have varied physical characteristics.

My sporting clays shooting has me favoring a 32" long barreled, very forward weighted, 7lb, 20g o/u or a 32" long barreled, very forward weighted, 7 3/4lb, 12g o/u.

Skeet, which I do little of these days, finds me wanting a slightly "quicker swinging" gun than the sporting clays guns I have. What little trap I shoot is done with my long barreled sporting clays guns, since I'm not a proficient trap shooter anyways.

My walked up over a flushing dog quail hunting has driven me to favor a 6lb 26" barreled, 20g or .410 gun. If I had a pointing dog, I would consider a longer barreled, "slower" swinging gun for the prepared shot, but not necessarily heavier (gotta carry the thing across the same terrain, just the same).

So, I don't even imagine a Brit "game gun" would suit my clays shooting better than my cheapo production guns, but may be as good or better than some of my various guns at my quail hunting.

Pheasant hunting the flatlands is yet another story. A 6 - 6 1/2lb. featherlight "game gun" doesn't quite seem ideal to me. Too "whippy" IMO. Phez are slow to take flight and accelerate. Once up to cruise speeds, they need a steady lead and consistant follow thru. This means a gun that has some swing heft is o.k., even desirable. You do have to carry it, but usually not up and down hills/mtns like quail/chukar. So, a slightly heavier gun is manageable.

So, just in my little knothole of the world, I like vastly different characteristics in guns for my different hunting. A classic Brit "game gun" would/does/did have a place in my shooting, but not for everything.

As a gun lays, it has it's inherent qualities.
Now how it fits?????????
But!
The better the gun's balance as it lays, the better it is for either ground swatting, or sky blasting.

Some fact. Some myth. No majic.

And the problem remains, LG, that what you consider good balance may not be good for me. Good for quail may not be good for trap. So, we must consider balance (both the teeter-totter definition and the summation of handling definition)in the context of both the individual shooter and that shooter's application.

Shooter's needs and body types do vary, but has little to do with the natural balance of a gun in it's restful state.
It maybe perfection until you put it to your shoulder, and then into motion, but that's not the gun's fault.

There is a artical in the Jan-Feb 08.SSM."A Question of Balance".I will be Interested if there any 'Comments"!!!!!CC

Mmmmmmm! LG, would you then say, "That gun has perfect stock dimensions in its natural state and it is the shooter's fault that it doesn't fit him?"

XC - looking forward to additional points of view, data, and commentary.

Well, now that my Shooting Sportsman has arrived it would appear as though Mr. T. has enlightened us to the stockers way.

Hairy

SSM arrived and XC's article read. Comments as follows.

XC - congratulations on a well written and informative article. Second, you have my admiration for having the integrity to do a repair when you could have done more costly work - well done!!

I find several points worth noting and possibly discussing.

- Buying an expensive gun assures neither proper fit nor proper handling; both are personal needs and may require adjusting.
If you are going to buy a gun, other than a bespoke one, you will need to address fit and handling.

- Every shooter should keep records of the fit and handling of as many guns as possible. It is important to develop a personal envelope of fit dimensions and handling numbers, whether you are buying a London best or an 870.

- Balance moves as the weight and/or location of weight changes for the gun. Further, balance can be in a location that is unsatisfactory for the owner and can negatively inpact both the shooters accuracy and enjoyment of shooting the gun.

- Balance can be adjusted in planned and measurable ways.

- A temporary adjustment should be checked with the shooter for suitability.

- If the shooter does not have a known envelope of preference, a temporary adjustment to known average values will be a good starting point. There seems to be considerability variability in sensitivity to balance among shooters. Some can detect a 1/4" move in balance point and others require much more for detection.

- Recoil pads often approach the 6 oz XC used to rebalance these guns. Beware of unintended consequences to handling when dealing with recoil pads/reducers, etc.

As I said, good article.

It's been very interesting and educative to read this thread. But there's something I'd like toask y'all about. A few years back I read a very old article discussing balance. The author of the article claimed, that a (double) gun has perfect weight distribution if:

- the rear end of the gun (the stock and the action, with barrels and fore-end removed), taken separatly, balances at the grip (i.e., where the right* hand holds it)

- the front end (the barrels with the forearm attached, minus the stock) balances exactly where the left hand grips the gun when mounted

- the total gun balances exactly between the place where the right hand holds it, and where the left hand holds it.

Sorry if the description isn't clear enough, but I hope you see what's being meant. I don't know how much truth is in this method, since I'm not competent enough, but it seems rational and seems to work when tested on real guns.

What do you think about it?

___________
I'm being slighlty P-in-C here, speaking of right-handed shooters only, sorry...

HD, just tried the method you mention with an AyA 53 16 bore and the two "parts" do balance rather nicely when held separately as I would shoot it.

The gun has a total weight of 3.156kg or 6#15.2oz and the T-T balance point is 4 3/4" in front of the front trigger. When you pick it up for the first time it feels very "front" heavy.

Rocketman, according to your vast experience on the subject, would adding weight to the stock, i.e. moving T-T balance point backwards, improve its handling?

JC

HD - I don't agree that one method of setting balance point will achieve "perfect weight distribution." Different shooters prefer different balance points based on their individual shooting styles and physiology. I'll do some research with this method. Certainly, it take into account hand placement, but I expect there are other factors.

JC - "improve its handling" is a subjective evaluation. Only the individual shooter handling the gun can judge if it is improved. The focus of my work is to establish objective measurements so shooters can know and communicate what they are evaluating. The weight, balance, and swing numbers of a given gun are objective. How you feel about them are subjective. I do not believe the goal is to establish generally optimum handling, rather, it is to establish optimum handling for each individual shooter. This is the same gosl as stock fit.

Rman, subjectivity notwithstanding, and based on your handling of modified guns,i.e. guns that may have had weight added to the stock, what is your subjective opinion concerning their new handling characteristics ? :-)

JC

OE configuration:
Ithaca NID 4E BLE Trap #457465 - single selective trigger - 12 gauge 2 3/4" - 32" bbls - 14 1/4" LOP (3/4" pas): 8.69 pounds, 6 1/2" balance, 2.48 unmounted, 10.55 mounted, 11.50 HWR.

Modified configuration:
Ithaca NID 4E BLE Trap #457465 SST - 12 gauge 2 3/4" - 32" bbls - 15 5/8" LOP w/ CSMC 1 1/2"pad + 5/8" spacer: 9.125 pounds, 5 1/2" balance, 2.95 unmounted, 11.73 mounted, 12.24 HWR.

Differences: 1 3/8" increase in LOP - 7 oz weight gain (all at butt) - balance moved rearward 1" - unmounted swing increased 20%, mounted swing increased 12%, and HWR increased 7%.

For my purpose of trap shooting, this gun is improved in handling for me. Also, I shot sporting clays well with it at the Vintage Cup. I will soon baseline it for skeet. I seriously doubt that I would carry it afield where a lot of ground was to be covered, though.

There is no general answer as to hurt of help handling. Modifications must be focused on both of the issues with fit and with handling.

Does that answer your question?

Yes, the mentioned author is from the school that believes in equal weight destribution between the shooter's hands. This school has some good arguments for their view - but I agree the subject of balance is subjective.

However, I have found the method of "taking the balance" not only of the whole gun, but of its parts (stock+action vs barrels+foreend) as well, extremely useful in practice. Of course, Rocketman's machine is the best way, but, let's say, it's not always readily availaible. When you only have about fifteen minutes in a shop to "just look" at a gun, you aren't likely to bother with the formulas, yet might need something more exact then simply balancing a gun. Let me illustrate.

About a year ago I was considering a domestic sidelock of 1944 vintage, and noticed, that "on the pencil" it balanced almost exactly where my own old 12ga did - ahead of the "between-the-hands" point enough to lassify the gun as "muzzle-heavy". Yet, when mounted, my gun felt much better balanced. I took the guns apart. The "rear ends" of both guns balanced properly. But the barrel+foreend bits didn't. My old gun's "front end" balanced where my left hand holds it when mounted, but the 1944 sidelock's barrels balanced noticably ahead of that spot.

I took a closer look at the 1944's barrels. They were strangely shaped, almost conical, quite unlike the classic "leggy" shape of double gun barrels. That 1944's barrels had a lot of metal in front.

So, to my personal taste, both guns were ill-balanced, but for different reasons. My old gun had barrels that were relatively heavier than the stock+action. The 1944 sidelock was the correct front-end-to-rear-end weight ratio, but the weight destribution of the barrels was very wrong, and ruined the balance - and the "feel" - of the whole gun!

The above is just personal observation and opinion, and if I'n wrong, I'd like to know it.

I find the idea of balance of the 'two halves' of the gun individually quite interesting. I have never done that, but, will. My problem is, do you use the middle point of the hands position? or the most forward? most rearward? I have a rather large hand and where one measures from could vary as much as four and a quarter inches!

Hairy

Any well made, well thought-out gun will be good enough for most.
They are not Italian violins, nor atom smashers.
They are triflings that most do not have a feel for.

HD - The method you describe will work if you establish a weight proportion for the two pieces (stock + action and barrels + forearm). You must weigh and balance the whole gun and each of the two described units. Then you must compare overall balance, compare for each unit balance to overall balance point, and weight proportion.

I'll run a few tests and see how this works out.

R'man thank you for your feedback. Drilling a hole and doing some experimenting
should not do a lot of harm.

JC

JC - I'll use differing guns and tape on weights as needed. I'm thinking about how to lay out this experiment. Interesting idea.

I've dug through my (sadly limited amount of) books. One of our shotgun gurus, S.A. Buturlin, states the weight of the complete gun ought to be 2.0 to 2.2 times the weight of the barrels (without foreend). Another expert believes the weight of the "rear end" devided by the weight of the "front end" should give anout .995 to 1.005 ratio. (I can't say if these ratios were invented by the respective authors or picked up from W.W. Greener or somebody else.)

The obvious guess here would be that if a shotgun must have some weight-forward and still feel balanced, the barrels+foreend should weigh a bit more than the rear end, yet balance at the fron-hand grip spot (BTW, I think the "grip spot" for the front hand should be determined by the middle of the palm)

I can hardly wait for the results of the tests

HD - I use middle of the palm for both front and rear hand when calculating weight in each hand from balance and hand placement. I'll be awhile yet on this. Anyone can do this at home - all you need is a weighing scale and a balance fulcrum/rod (pencil), masking tape, and a tape measure.