Over / Under Doubles?

22 November 2002, 06:11

Andre Mertens

My regular drive hunt rifle is a FN-Browning O/U in 9,3x74R. I scoped it with a Swarovski 1,25-4x24 with "battue" reticle in German claw mounts. It's handmade, engraved and signed by Josï¿½ Baerten, former FN's head engraver and is stocked in presentation wood.

O/U doubles are as popular as S/S in Europe and both options are usually offered by each gunmaker. Best known are Lebeau-Courally (the absolute top, see their website), Francotte, Dumoulin, Beretta, Chapuis,... - no, I won't count Zoli in this select company [Wink]

. Far beyond, you'll meet the dark crowd, with its numerous gun-butchers pretending to build double rifles from 20 ga. receivers... BERK !

23 November 2002, 09:20

Sauenjï¿½ger1

Have a look on http://www.krieghoff.de/english/krieghoff.htm
there you can see the trader for Australia.
Their english web sites are still under construction.

If you use a TS modell, then there is no problem with hot barrels. At those kind of double guns the barrels can be adjusted and it is no problem to change the ammo and to re-adjust the barrels. Also they have an accuracy which comes near to the bolt rifles.

Or have a look on
http://www.blaser.de/english/produkte/b9597/blaser97.htm
Here the english website is working.
It has nearly the same feature than Krieghoff.

Best regards

23 November 2002, 01:48

EXPRESS

I have 2 U/O doubles, one in .375H&H the other 9.3x74, both Beretta both with what we call "pigs foot" detatchable claw mounts.

I personally prefer U/O in shotguns as well, and have heard that the U/O configuration in a rifle has some technical advantages over the traditional sidebyside. Two points of advantage essentially; Firstly the barrels can not be perfectly paralell, so they are aligned in converge at a certain distance - let say for arguments' sake 100m. Therefore when you are within and beyond that range the shots will be placed across a horizontal plane, wich is more annying to compensate for. In an U/O the bullets will co-inside and contine in a vertical which would be less noteable as we are used to conpensating for rise and drop.

Secondly there is a "tortion" theory whereby in a side by side the bullet spinning in the rifling in both barrels, in both bith barrels in the same direction creates a tortion effect that tends to warps them out of alighnment, espcially if you shoot with a scope this should be noticed.

I have never been able to distinguish either of these traits in either gun, so it could all be micro science or just plain crap.

[ 11-27-2002, 13:20: Message edited by: EXPRESS ]

25 November 2002, 10:32

MacD37

quote:
Originally posted by EXPRESS:
I have never been able to distinguish either of these traits in either gun, so it could all be micro science or just plain crap.

UHMMMM HUH!!!!! It sure is, all crap! [Big Grin]

The O/U is easier to regulate, but it is still a convergence of barrels, none the less, and just like the S/S, the rounds cross at exactly the distance they were regulated for! [Wink]

The reason the barrels have to be regulated in either type is, because of something called barrel time. This is the time the bullet stays in each barrel, during recoil. In an O/U, each barrel recoils differently, because of it's possitioning above,(top barrel) and ON (bottom barrel)the"horizontal center of gravity" (HCG) of the rifle. The bottom barrel being in line with the HCG, recoils back, and up! The top barrel being much more above the HCG, recoils back, and violently UP! This difference being evident between the barrels reaction to recoil, one knows the barrel time of each barrel will have the bullet exit the barrel from different possitions in the recoils arch, causeing two different hits on the target if the barrels are exactly parallel. Also the felt recoil is much more from the top barrel when useing very large chamberings,being above the HCG than it is from the bottom barrel which is in line with the HCG!

The S/S barrels being equil as to their relationship to the HCG, will differ in their recoil, but in a different dirrection. The right barrel will recoil up, and to the right, the left barrel will recoil up, and to the left, but equilly.

The regulation, and crossing of shots is not the difference between the two, But both have things about them that are better than the other, it is just that the S/S has more positives, than the O/U, especially for dangerous game, and large chamberings, as noted above!

I own both types, and have owned many more of each in the past, and my choice is the S/S every time if the cartridge is larger than the 9.3X74R, or 375 Flanged. IMO, the O/U is a nice rifle to carry, and in lighter chamberings, makes a very nice rifle for hunting things like deer. Also, IMO, the O/U is the only double rifle that is complimented by a single trigger, as most are not built for Dangerous game, so a trigger failier is not life threatening, but simply an inconvenience, that sends the "out of service" rifle to the gunsmith. All that is missed is a shot at a deer. However, if ether type is to be used on dangerous game, there should always be two triggers! If one trigger is broken, it simply doesn't effect the other barrel with two triggers, and at least, you still have a single shot! The O/U is better suited to scope use, again, because of what they are usually used to hunt, deer,and hogs. The double rifle used for DGR, isn't usually used with a scope, be it O/U, or S/S, because the scope retards a fast reload. Add to that, an O/U must be broken very deeply to reload the bottom barrel, which is the proper barrel to fire first, and the scope interferes with the loading of the top barrel. The S/S has both barrels at the same level, and has only to be broken a small amount to be free of the standing breach. Even with a scope mounted, it is between the chambers, not over them. That thought is moot anyway, because a S/S double rifle for a DGR, are seldom fitted with a scope.

I like any rifle with two barrels no matter whic way they are fitted, it is just my opinion, the S/S double rifle is the best of the lot! [Cool]

26 November 2002, 09:25

N E 450 No2

I agree with MacD37. Side by sides are better suited for me because my eyes go like this,oo, not like this,8. [Big Grin]

26 November 2002, 05:46

Sauenjï¿½ger1

Yes, you are correct, if you will hunt dangerous game. The most of the O/U you can get also with double trigger (at least Krieghoff) but the biggest caliber they offer is 9,3x74R.
So they are not really destinated for this kind of hunting.
Their big advantage are the easy adjustable barrels. If you change the ammo at the old S/S you may have the problem, that the two barrels have to be re-adjusted, and then you have to braze and to make a new surface which costs time and money.
So here in Germany it is very hard to sell the old double barreled rifles without this adjustable barrels because of the new doubles.
But as you said no problem with the S/S for dangerous game. Here are the distances also not so long. Due to this the problems do not come so often.

Best regards