doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Hands on a real cutie

Credit is due D.A. for several "educational" efforts here; program for getting objectifiable results from patterning (which he will share with you), the "tier system" for valuation of British game guns (which he will share with you), and the terminology and test apparati of gun dynamics (which he is trying to share with you). Don has actually spent considerable time here trying to make some of us addlepated bumpkins THINK. I'm not much at physics or math but the acronyms MOI and HWR have a clear objective reality to me and, I'd hope, to anyone who has held a well-struck and balanced doublegun.

jack

I had the pleasure of having dinner with Don "Researcher" not so long ago. I can tell you that Don is passionate about bringing objective technical rationale to this community. We will all be educated from his efforts. Don is another of the many great contributors here and this particular effort of his is one of his great passions that only confirm his standing with many of us here.

Dave Noreen has that one patented, Chuck.

jack

None is so blind as he that would not see.

Sometimes a cigar is just a cigar.

GSY - it would be "Blastoff!" I shoot a variety of guns. I adapt to differing stock dimensions, to differing handling dimensions and to differing aesthetic stimuli. I am currently logging the results of shooting these differing guns. Stock dimensions are, of course, easy to measure (there goes that 'ole yardstick). Handling, to me anyway, is easy to measure. Aesthetics is still a mystery, but I know it is there. The good news is that I can easily share results that include stock dimensions and handling dimensions. Handling will not depend on my subjective judgement of the guns, rather it will be objective data for one and all.

JH - the gun will swing naturally about the balance point (center of gravity/CG/teeter totter point) unless some effort is expened to force it to do otherwise. The lowest swing effort will always be about the balance point. Shooters with differing prefered hand spread and differing physiques may well swing the gun differently, but the characteristic of the gun itself is at the balance point.

Mounted swing is calculated (from LOP, weight, and MOI at balance point) for the butt. I agree that the true axis is somewhere within the shooter's body, but we do get a useful characteristic by this calculation. BTW, this calculation is based on the parallel axis theorum which says we can calculate MOI about any axis.

Balance can be referenced to any point you choose. The (front) triggger is the mose useful and simplest. Balance tells you how the weight of the gun is proportioned between your two hands. Your back hand is always positioned to pull the trigger. So, we know the dimensional relationship between your back hand and the gun. Measure your personally prefered hand spread and you have all the information needed to calculate weight proportioning. Any other reference point will involve more measurements. Since hinge pin to hand and breech face to hand are not fixed, comparing guns becomes more difficult if they are used for the reference.

Half Weight Radius is simply a numerical statement of compactness. 10 to 11 is pretty average for most guns. Under 10 is more compact weight and over 11 is pretty dispersed weight. Direct comparisons require the guns' weight be similar. HWR has no value in telling you where to place your hands - do what you feel is natural for you or what a coach tells you.

The Ruger GL got its handling from referncing the handling properties of a Dixon RA, including MOI. Many gunmakers do MOI intuitively. Some are starting to pay attention to the possibilities of owner adjusted handling.

Cadet - I believe in magic. But, like the Conn Yankee of Mark Twain's imigination, some magic takes a little preparation. IMO, the magic happens when a shooter finds/has made a gun with accurate fit to his stock dimensions, handling properties that suit him best, and aesthetics that really hit his hot button.

DM - my life is very, very real. This is some of what I do for fun. I can measure to any required accuracy. However, I actually measure to those accuracies that are practical for this project. Parts of my database are published and other parts will be. At this point, it is a freebie for those interested.

DS - did I forget to mentiion this cutie is a 20 bore/gage/gauge/guage??

And, thanks to many for their kind words and support.

I know one thing for fact about XXV's-they are a bit hard on a 'feller's ears.

You wouldn't think 4 or 5 inches of barrel steel out there on the ends of the tubes would matter much....but, it does. Don, I have a 20 gauge Darne with 29 1/2" tubes, and a semi-pistol grip stock, that weighs but 5 lbs, 12 ozs that it would be interesting to see strapped into your tilt-a-whirl. I plan on it being my dotterage gun, if you will.
Best,
Ted

Ted, I have the following 28 bore Darn in the databasc, but no 20 bore. You can draw some idea from this. Light and fast!! Yours will be about this weight, but the longer barrels will slow it down a bit - maybe enough to make it managable with a deft touch.


Darne V-19 sliding breech, 5.69# weight, 2 1/2" balance, 0.93 unmounted swing, 4.37 mounted swing, 28 gauge, 25 3/4" barrel length, 14 1/4" LOP, 8.71 HWR

Stick to your guns Rocketman!

Rocketman and I often find we are discussing the same issue and approaching it from very different angles. However, we generally find that we come to the same conclusion. His science tells me what my experience would tell me were I there (but one cannot always be there).

I was sceptical in the tier system for valuation, but experience has led me to be at first interested and then respectful.

I think this MOI investigation based on the new machine is an avenue that deserves more work and look forward to more of Rocketman's findings as time goes by.

BTW, I love Churchill XXV Premieres. I have shot well with them when I have used one (all on live game)and the quality and handling go hand in hand......and I usually shoot with 30" barreled hammer guns.

Don,
Well, if you are really interested, comparing V and R grade guns is about like comparing apples and oreos. A V gun is more petite in the action, and will always weigh less in the middle than the same gauge R does, without wood.
There are no parts that interchange between an R and a V, the lockup is different, the cocking and firing is different, they dismantle differently, and they are usually built of two different kinds of steel. But, they 'kinda look similar.
We have to tie my R down someday, just to see how much, and if they differ in MOI. Every good double gun is an individual, it seems like to me.
Best,
Ted