I posted this on the Double Rifle forum without much success, so, duplicated hee!
Ok I have a 9.3x74R Tikka 512 (O/U). How do I "regulate" it and at what range? I have 2 big bore doubles and have tailored loads which group both barrels within 2" at 50 yards, and to point of aim. So, with a scoped O/U double is there anything different. It seems to me that there might be. First, the lower barrel may be adjustable, but my thought was to leave this as a last resort. So, should I tailor loads the same way as for a S/S double, and then see what happens at 100? I need some help here, as, from what I have read, this caliber should be at least 100 yard gun. What size groups would be acceptable at 100? etc. etc. Obviously with the scope, the impact/aimpoint can be adjusted easily. I am more concerned about typical acuracy levels with this caliber in a double, and the quickest way of getting there. In addition, Valmet seems to think that you don't need to have both barrels shoot to the same point. Thye seem to suggest that the lower barrel be usd for "long range". Anyone do that?
BTW. I like to consider the aesthetics of various loaded rounds. The Loaded 9.3x74R has got to be one of the best looking rounds around!
Thanks, Peter.
PS. I used the term "regulate" as a shorthand for "develop loads". I also have a 12 ga. and 7x57R barrel set, but that is a different question, perhaps somewhat similar to previous discussions.

My Valmet is a 12 over 223 combination gun. I'd certainly use the adjustable regulation feature first. If you plan only to use a scope I'd say zero the top barrel with the scope, then adjust the bottom barrel to strike the same as the top barrel. It goes pretty quick. If you plan to use the non-adjustable sights you'll need to zero the top barrel with a file, then adjust the bottom barrel to strike with it. I haven't done that with mine yet as I'm not sure I want to keep it, so Brennekes strike about six inches low at 50. A buddy of mine regulated a 308 O/U Tikka with no troubles and reported good accuracy.

Nordrseta, thanks for the response. It sounds like you have something similar to my 12 ga /7x57R. From looking at other threads, and your post, I am assuming that I should pattern the 12ga. first (or with slugs) and then use the barrel adjustments for "sighting in" the lower (rifle barrel). As I have a scope for that combination, would 100 yards be OK to sight in (and group) the rifle barrel?
Peter.

quote:

As I have a scope for that combination, would 100 yards be OK to sight in (and group) the rifle barrel?

That seems a reasonable place to start. The distance between the axis of the bore and the line of sight is quite large so some shooting at longer ranges until you understand the trajectory will be a good idea. Depending on the bullet weight you're using and the sort of hunting you plan to do a 200 yard zero might be more generally useful. Again, if you don't plan to use slugs in the 12 bore barrel there is no need to modify the irons; just adjust the rifle barrel to strike to the sights. And if you plan only to use the scope you can leave the lower barrel wherever it is and simply zero the scope.

Please forgive my supreme ignorance.......but I need info regarding a "regulation"-related subject. I bought a 9.3x74R double rifle in France...have not yet shot it...was informed that it was regulated for me using the Nosler 250 gr bullets they received from me......but the rib has a "key" protruding from the muzzle end....that is apparently the regulation device. Do I remove the key before shooting the gun??...or is it supposed to remain in position?

quote:

Originally posted by conifer:
Please forgive my supreme ignorance.......but I need info regarding a "regulation"-related subject. I bought a 9.3x74R double rifle in France...have not yet shot it...was informed that it was regulated for me using the Nosler 250 gr bullets they received from me......but the rib has a "key" protruding from the muzzle end....that is apparently the regulation device. Do I remove the key before shooting the gun??...or is it supposed to remain in position?

I'd ask the maker, just to be on the safe side... Tell us more about the rifle, if you please.

That is a wedge for regulating. after you take delivery of the rifle and you are happy with the regulation then it is intended to cut it off. It's not necissarry to do this and never remove it ( that will only be done with a tourch anyway) I woulden't worry about it

Thanks a million fellas. The maker is/was French...St.Etienne locality...probably defunct now...linked up later with "Brevette" name....I will dig gun out of safe and report details.

The rifle is a "Gaucher" S/S double.

Peter,
Do you have the owners manual for your gun. If it's the tikka 512 the owners manual explains regulating the barrels.
Here's a link to the owners manual if you need one.
Nitro Express Valmet owners manual

Again if it's the Tikka 512 I haven't noticed a change when I take the scope on or off the gun.

Thanks Foxfire, I did get a link to the manula over on NitroExpress. I skimmed it, but it did not really say which direction to move to make a specific adjustment. I have not checked the rifle itself yet. I shot some factory rounds and I have loaded up some reloads but haven't made it to the range yet. To be quite honest I still have n;t got an answer to the question about how to handle load development ie. should I find a load that groups well with each barrel separatley and then adjust the barrel regulation?
Peter.

quote:

Originally posted by Peter:
but it did not really say which direction to move to make a specific adjustment

First, shoot your rifle, one or two rounds through each barrel with your "regulating" load. If the rifle hits the target well enough before "regulating", work up loads first. Use the same load for both barrels.

Note if the barrels are crossing say at 100 yards ie the bottom barrel may shoot above the top barrel.

Most Tikkas seem to shoot horizontally well enough. If so no need to touch the adjustments at the muzzle.

To change the impacts of the two barrels vertically, loosen the lock screw in the wedge. The wedge has an angled surface. To bring the barrel impact groups towards each other, increase the wedge pressure by sliding it so more of the slope is against the barrel. If they are crossing already, move the wedge down the slope. A mm or two can make quite a difference.

I haven't adjusted the front setting, but the same principles would apply. The front setting will move the groups left or right.

Trial and error to get them right.

To move the wedge you may have to give it a slight knock. Otherwise some pressure with your thumb should do it.

My preference is to get the top barrel shooting about an inch above the bottom group at 100 yards, ie a similar distance that the barrels are apart.

If you want test it at 50 yards (you might start at that distance anyway), 150 yards, 200 yards etc.

Nitrox, thanks very much. Exactly what I was looking for. The Norma 286 factory loads shoot about 2" apart (1 pretty much below the other) at 50 yards. That's why I was concerned about the sighting in range. The lower bullet may well be climbing and be closer at 100! I have some "play" loads (Speer 270 gr) that I will make sure are on the paper at 50 and then try at 100. From then on I will do all my shooting at 100 (probably)and then adjust the scope for point of aim/impact for 100 and 200. I LOVE the Q/D scope mounts. I have no idea how they could possibly work, but I have two mounts and scopes, one for the 9,3x74 barrel pair, and the other for the 12ga/7x57R barrel pair.
Thanks again, Peter.

I forgot to add:

One of the barrels is "fixed". The other barrel is "regulated" to move its bullet impact to near the fixed barrel.

The open sights or scope need to be adjusted to get the impacts near the point of aim, just like any other firearm for the fixed barrel.

***

Peter

I worked up a 286 gr Woodleigh Protected Point load in 9.3x74R that is extremely accurate. Mostly one hole two-shot groups, with a small gap between the barrel impact points.

They have worked pretty well on water buffalo and scrub bulls too, a few pigs and warthog, horses, donkeys etc.

I have a .30-06 double barrel set for my Tikka that I need to try out too when it gets here.

Those scope mounts are hard to get too!

Nitrox, I would be interested in your load for the Woodleigh PP's if they are using a powder that is availible in the States. I got the Speers just for practice and shooting for fun. For hunting, I was thinking of using Nosler's or Woodleighs.
Thanks, Peter