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Bart B. Posted - Aug 14 2006 : 06:34:24
Many years ago, I had an opportunity to shoot the left barrel from a Rigby .470 Nitro Express. After being quickly being pushed almost over backwards, I developed an interest in these side-by-side monsters. Its owner enlightened me as to its construction and how it's made. One critical part of how double rifle's are assembled has often provoked controversy. Here's the issue.

Barrel alignment. Or, "regulating" as it's called. Both barrels have to be aligned such that they shoot to the same point of aim; typically at 50 yards. These behemoths have quite a bit of jump, or recoil before the bullet leaves the muzzle. That recoil causes the muzzles to swing left when the left barrel's fired; to the right when firing the right barrel. How much depends on the bullet weight, its velocity and how much the rifle weighs. In order for bullets from both barrels strike the same point of aim at 50 yards, the muzzle axes must converge at some point between the rifle and target. It's typically 20 to 30 yards to regulate at 50 yards; they toe in at about 7 MOA. A popular way of doing this is to have both barrels parallel at the breech end so their chambers are at right angles to the action, the muzzles clamped together with their axes closer than the breech axes, then a wedge is slid between the barrels and moved forward or backwards to change the muzzle's toe-in angle. Both barrels are actually bent inward at their muzzles and this can be seen by looking down their bores.

There are some folks in the shooting sports who claim there is no movement of a barrel until the bullet's left. And others say there is 'cause of the equal-and-opposite force syndrome. Which group are you in?
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Big 4 Posted - Jul 02 2012 : 14:21:15
I have used David Yale and Butch Searcy to regulate my doubles and they can do it in a hurry..Those guys that build doubles should not hate doing it, its really not all that complicated and the more you do the easier it gets of course and David and Butch have done literally thousands of them. That said on the adjustable rifle you mention..I would regulate it for one load and stick with that.."Monkeying with a double is trouble", one load fits all is good advise, save the other stuff for the bolt guns.
9.3x74r Posted - Jan 27 2009 : 08:48:34
Thanks for the welcome. A big bore is good for the old buff but the finances would not let me go that way as a 470 nitro from Chapuis out here start at 15,000 with a Merkell about the same price. The Baikal I have ordered is in the second shipment to come to Australia. I contacted the importers and they informed me that they have 12 more coming into Aus so I jumped in and ordered one. I have been looking around the forums and the news is a little mixed about them, a bit agricultural but functional. The reports say they shoot well after the bugs are ironed out. The good feature is the adjustable regulation system so various bullet weights should not be a problem. I shot a large feral scrub bull with the 9.3 and the bullet was under the skin on the off shoulder so it seems to have the grunt.

Two barrels are better than one
skyline Posted - Jan 27 2009 : 08:26:38
9.3x74R.........welcome to the nest. I have shot your name sake and it is a great cartridge. Very common in Europe in doubles and drillings.

I was looking at getting a .45-70 double from Baikal, but then I was informed that they were actually not going to offer was available in .30-06. Hope yours comes to pass.

You live in an area of Australia I have always wanted to go to. Having water buffalo around gives you something worthy of a big bore double rifle.
9.3x74r Posted - Jan 27 2009 : 08:15:37
Hello all this is my first visit to your forum and my interest is in double rifles. At the present time I have a Chapuis UGX SxS in 9.3x74R which I have had for about 5 months and have on order a Baikal 45-70 SxS which may arrive in the next month or six who knows. I live in the Northern Territory of Australia in Darwin so I get the occasional shot at Asiatic Buffalo,scrub bulls and feral pigs, my other rifles all single barrels are in 375H&H,300 Win,44Mag,32-20

Two barrels are better than one
Wolfgang Posted - Jun 04 2007 : 04:45:01
I'd like to read it.

To put a web address in, point to it in the address bar of your browser window and left click it. This will open a drop down menu, scroll down pointing to "COPY" and left click. Right click in the reply text box here, to open the drop down menu again and right click "PASTE". The message board program won't add the HTML mark-up to make it an active link until you hit the "post reply" button but it'll work.

"Carry the battle to them. Don't let them bring it to you. Put them on the defensive and don't ever apologize for anything."
Harry S. Truman
Wolfgang Posted - Jun 03 2007 : 22:02:09
Definitely, most doubles are "one load only", just the nature of the beast but then again I've met a lot of singles and bolts that are also "one load only" too.

I know I've talked with a few double builders and they all hate the regulation stage. Sometimes they fall right into place and sometimes they are a major pain in the butt. Machinist I used in PA built his own double in 8x57JRS, he was well versed in the regulation process but he worked on that thing for many months (part time) to get it right.

"Carry the battle to them. Don't let them bring it to you. Put them on the defensive and don't ever apologize for anything."
Harry S. Truman
Wolfgang Posted - Jun 02 2007 : 21:11:57
This a topic of great interest to me as well, so many variables and theories it can scramble one's mind in short order.

I've been doing research on another project for a few years now and in the process got side-tracked with some unique double rifles. Speaking of "wide between the eyes", there was a fellow in Finland building doubles in the early 20th centry that had true parallel bores. The OD was tapered as normal but he assembled them with tapered top & bottom ribs so that both bores remained parallel to each other from the breech to the muzzle. They don't have the slim look like the southern european doubles but they are definitely unique in their own right. The other intesting thing about these is that the right barrel was done with a left hand twist and the left barrel with a right hand twist.

Don't know that I'll ever get around to it but at some time in my life I'd like to build a matched pair of doubles, one .66 rifle and one 16ga shotgun, both in flintlock.

"Carry the battle to them. Don't let them bring it to you. Put them on the defensive and don't ever apologize for anything."
Harry S. Truman
dave375hh Posted - Aug 30 2006 : 14:22:01
Your illistration of recoil effect is correct. Further SxS shotgun barrels are made to converge at 35-40 yards also. The same effect can be seen in handguns also. If you take two 200 gr loads for the same gun and make one a fast hunting load, and the other a slow target round. The target round will strike higher on the target than the fast hunting load. The reason is barrel time difference. The slow target round is in the barrel longer and imparts more recoil deflection than the fast round.

The effect in a SxS is greater due to the barrels being outside the centerline of the gun.

Recoil starts as soon as the bullet or shot charge moves. Action /reaction

skyline Posted - Aug 29 2006 : 20:37:18
Bart this is a very interesting topic for those of us that love double rifles. As you have pointed out, regulating a rifle is an art and some people are much better at it than others.

I for one am really happy to see the renewed interest in these rifles over the last couple of decades. I have shot a number of doubles over the years and really like the look and feel of these rifles.........which probably goes back to my first shotgun, a 16 gauge side-by-side. One of these days I hope that I can afford to actually own one.

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