Kodiak double sights

[George]

Can someone explain how the double rear sights on Kodiak double rifles are intended to be used? One for each barrel at the same range? One for each barrel at two different ranges? Since the bores are less than an inch apart at the muzzle and it is stated that each barrel points at the same spot at 75 yards, is there any chance using only 1 sight on the center rib would work for hunting?

Thanks.

Spence

 

[BillinOregon]

Spence: Sometimes the Kodiaks are well regulated at 75 yards, and sometimes not. I have had several, and most are usefully accurate using just one of the sights. I believe Pedersoli intends one sight for the left barrel and one for the right. I'll let you know how well regulated the sights are on my new .72, due here tomorrow.

 

[Supercracker]

"Supposedly", there will be a magic load that will make both barrels impact at the same spot allowing you to use one leaf for that spot and the other for one barrel at a longer distance. With enough experimentation you will find that load.

That said....I haven't found it.

In all fairness, I haven't tried very hard and will probably end up zeroing one leaf for one barrel at 50yds and the other for the other barrel at 100. Where and how I hunt most of the shots will be very close, so it hasn't been an issue.

I have a Kodiak .50

 

[George]

Reading various discussions about getting double rifles to shoot to the same point, I have seen repeatedly that a lot of guys seem to believe low charges cause trajectories which tend toward the midline while higher charges cause bullets to hit farther right with the right barrel, farther left with the left. That seems illogical, so I must not be understanding what they are saying. Changing the charge in a single barreled gun changes the elevation, not the windage, why would it be different with a double? Can someone straighten me out?

Spence

 

[Supercracker]

The barrels on a SxS don't rest over the centerline. The recoil from the left barrel has a slight leverage on the rifle towards the left and the opposite on the right. More recoil on the left side will tend to move the rifle very very slightly more to the left before the bullet leaves the barrel and the opposite on the right.

Picture drawing a line down the center of each barrel and the center of the rifle. The distance between the CL of a barrel and the CL of the rifle is like a lever. I'm told this is why trap shooters use OU guns. because the barrels rest along the centerline of the gun they have no tendancy to pull the gun from one side to the other allowing a faster transition from one target to the next.

 

[George]

The recoil from the left barrel has a slight leverage on the rifle towards the left and the opposite on the right.

Interesting idea, each barrel bouncing off the other, but I'm having difficulty getting my head around it. I have no experience with double rifles, but have done a fair bit of shooting roundballs from SxS shotguns both percussion and flint. It usually is a given that the barrels won't be regulated very closely, but changing charges moves the point of impact up or down, not side to side, in my experience. If a right barrel shoots 2" to the right at 25 yards with a beginning charge, it will move up or down slightly as charges are changed, but still be only 2" to the right. I never noticed any tendency for groups to move right or left with changing charges with those shotguns, can't think why rifles would behave any differently.

>>>>I'm told this is why trap shooters use OU guns. because the barrels rest along the centerline of the gun they have no tendancy to pull the gun from one side to the other allowing a faster transition from one target to the next.

 

[paulvallandigham]

Just as you pad the forearm of a stock to keep the gun from shooting HIGH, the barrels of a double rifle or double shotgun tend to vibrate, and throw their balls/bullets away from any solid object they touch. IN S X S's, the barrel rebound against each other, tending to throw balls right and left of the right and left barrels respectively. To compensate for this problem, gunmaker would put a slight taper to the barrels so that they actually shoot together at the same POI at a given range.

The Famous British Double Rifles used in Africa were "regulated" to hit the same POI at about 35 yds. These were the big guns used on Elephant, Rhino, Hippopotamus, and Cape Buffalo. Some Professional Hunters ordered lighter caliber rifles ( .375 H&H) regulated at longer distances( 75-100 yds), and used them to shoot lions, and Leopards, as well as thin skinned animals from the deer family, found on the plains, where distances can be longer than where you hunt Elephants etc.

 

[George]

Just as you pad the forearm of a stock to keep the gun from shooting HIGH, the barrels of a double rifle or double shotgun tend to vibrate, and throw their balls/bullets away from any solid object they touch. IN S X S's, the barrel rebound against each other, tending to throw balls right and left of the right and left barrels respectively.

I take your point, but I wonder if the analogy is an accurate one. These barrels are soldered together and are essentially one piece, not like something hard touching the barrel. The right barrel can't rebound against the left because whatever vibration and movement occurs in the right also occurs in the left. Or so it seems to me.

Spence

 

[Lorne Johnson]

The intended purpose of the two leaf sights on current Pedersoli Kodiaks is for different distances. The higher leaf (rear?) for 100 yards and the lower leaf for 50 yards. The factory gets sights each barrel using a laser to point of aim at some metric distance (which Anglophiles insist is 75 yards) and braze the barrels together at that point of aim. Then the guns are test fired on a range and, if necessary, some don't-try-this-at-home filing is done to finish the barrel regulation. Since Pedersoli (Garrone Italy) states FFg as specifed powder and gives a recommended load, it would appear that that load of Swiss FFg is the intended magic load.

In the context of old-world craftsmanship and the regulation of double rifles, this is a fairly superficial process. It often seems to work quite well, probably because of the laser bore-sight. Kodiaks retail for around $1100 or $1200, which is ridiculously low in the world of double rifles, so it's hardly reasonable to expect them exceed the 2nd amendment requirement of being "well regulated." Working up a "best load" with one barrel is a task, doing it with two attached barrels is an art.

 

[paulvallandigham]

WADR, They are NOT ONE PIECE. Barrels are made of different metal than the solder. They vibrate differently than will the solder. That is one of the reasons why solder joints occasional break loose on old guns.

If you have ever stretches a clothes line rope as tight as possible, and then "plucked it" in the middle, you can see the harmonic waves associated with the vibration. Pluck the same rope some place away from the middle, and you get different waves. Vibrations in materials is what makes the sound in musical instruments, from violins, to brass and reeds, to drums. The sounds produced not only vary in pitch, but in tone, due to the materials with which the instrument is made, the shape of the instrument, its size, and the kind of vibrations that are given the instrument by the performer.

A piece of lead pushed through a steel tube under high pressure of expanding gases causes that steel tube to VIBRATE. If its held only at one end, the vibrations can be violent enough to almost be visible to the naked eye. Certainly, if you put a finger LIGHTLY next to the barrel near the muzzle , you should be able to feel the vibrations. You can solder the barrels together their full length, and the steel in both barrels will still vibrate- only differently, and with sine waves flowing away from the joint.

One of the benefits of using Octagon shaped barrels( in muzzleloaders and the now uncommon modern, breechloading rifle) is that the Octagon is an interlocking combination of Three( Or more,arguably) Triangles, the strongest structure in geometry. Those triangles help lessen and dampen the harmonics of the barrel, to give the gun more consistent barrel movement( vibrations) from shot to shot, even when there are slight variations of powder charges( volume measurements) and Muzzle Velocities. Round barrels whip back and forth a lot more, by comparison, unless the diameter of the barrel is at least 3x the diameter of the bore. You simply don't find that in modern " sporting rifles" these days. Some modern Target barrels have "flutes" cut into them, to stiffen the barrel much like an Octagon shaped barrel, only inverted.( Convex vs. concave).

 

[doublesnider]

Hi,
Shooting double rifles is very different to other kind of shooting.
My kodiak (.58") with REALs and 109-115 gr of coarse FFFG shot less than 4" both barrels at 55 yds shooting standing and leaning over a branch.
With lower charges shots cross, ie left barrel shots right and right barrel shots left.
Muzzleloaders work different than classical nitro express doubles.
As stated by Forsyth in 1863 increasing the powder charge you have more recoil and it uncross o shot apart.
By the way doubles have erratically shooting from the bench.
If you work hard, most Kodiaks shoot accurately.
There are some other sites with experts.
Hope this helps.
Martin

 

[BillinOregon]

Spence: For a factual discussion of the physics of double rifle shooting, get a copy of Graeme Wright's "Shooting the British Double Rifle," third edition. While the book focuses on cartridge rifles, the principles apply to our Kodiaks. This book is considered the bible of double rifle shooting, and thoroughly explains the phenomenon of crossing shots.

 

[CoyoteJoe]

The recoil from the left barrel has a slight leverage on the rifle towards the left and the opposite on the right.

Interesting idea, each barrel bouncing off the other, but I'm having difficulty getting my head around it. I have no experience with double rifles, but have done a fair bit of shooting roundballs from SxS shotguns both percussion and flint. It usually is a given that the barrels won't be regulated very closely, but changing charges moves the point of impact up or down, not side to side, in my experience. If a right barrel shoots 2" to the right at 25 yards with a beginning charge, it will move up or down slightly as charges are changed, but still be only 2" to the right. I never noticed any tendency for groups to move right or left with changing charges with those shotguns, can't think why rifles would behave any differently.
Spence

I believe Supercracker explained it pretty well. With shotguns it is rather difficult to locate the exact center of the pattern so it is hard to say if your 36" pattern has moved a couple of inches. Hopefully you'll get a smaller group with a rifle so slight changes in group location will be more noticeable.
With either rifles or shotguns any change in the projectile weight has a more pronounced effect than does change in the powder charge alone. Going from a 280 grain ball to a 500 grain minie will very definitely "uncross your barrels". :haha:

 

[George]

With shotguns it is rather difficult to locate the exact center of the pattern so it is hard to say if your 36" pattern has moved a couple of inches.

Yes, that would be true, but I was shooting patched roundballs in the shotguns, 1 1/2"-2" groups at 25 yards.

When this heat wave finally breaks and I can get out for some shooting, I'm looking forward to checking these ideas out first hand.

Spence

 

[George]

Thanks to all for the interesting discussion, references, book recommendation, etc. It seems that I'm going to have some new concepts to work my way through when I can get my double rifle to the range. That will be fun. I'll report back on how my rifle does, hope it's one of those that took its regulation seriously. I'm hoping to use it in early muzzleloading deer season in late October, if I can get it ready.

Spence

 

[Zonie]

Before taking your double afield, check with the Game & Fish department.

Some States like mine do not allow multiple shot guns to be used during the Black Powder season.
They insist on single shot rifles.

 

[George]

Some States like mine do not allow multiple shot guns to be used during the Black Powder season.

Thanks, Zonie, they are legal in Kentucky.

Spence

 

[BillinOregon]

Not legal in Oregon, either, during a muzzleloader season, but I can use mine during the regular seasons -- and for bear.
Nice looking rifle, Spence. Very nice wood!