CVA Express Double rifle sights HELP

[kens]

I have a CVA double .50cal rifle, 1:48 twist. It has a open iron sight on the center rib, and it shoots pretty much lousy. it is too fast twist for round ball and too slow for a conical.
Best group so far is a .45acp bullet in a sabot.
But my real concern here is the sights, only a single sight and the barrels are not regulated well.
I can sight in a zero for either barrel, but the opposite barrel is way off. If I split the difference, both barrels are way off.

How can I fix this?? CVA no longer supports this discontinued item.

A gunsmith said to mount see-thru scope mount, and zero one barrel to scope, and other barrel to open sight. This seems bulky to me, besides I doubt that the iron sights are tall enough to see over the scope bases.
Anyone have a better idea?

[turtlezx]

how about 2 flip up sights 1 for each barrel ??

[Skipper]

You need to regulate the rifle. CVA recommends the use of PowerBelts in these rifles.

The Spanish mfg's email is info@dikar.es
They might have info about the original regulation, if any.

[fouronesix]

No mystery- there's a reason good double rifles are expensive.

For this type novelty rifle, just find the most accurate load for the most accurate barrel and adjust sights for that load and that barrel. Then use the second barrel for the charging (fill in the blank) critter at close range :roll:.

Pure random and unlikely luck to be able to regulate two barrels, using a particular load, when the barrels have not been regulated.

[Col4570]

Those Barrels converge to a point and where intended for close up work.Keep the same loads whilst shooting at different distances until you hit on the correct distance.A bloke at our range has found that 75 Yards is the best for his load with his original double Muzzleloading Rifle using Black Powder.At 100 yards the Bullet hits to the left of the Bull with the Right Barrel and to the Right with the left Barrel.If the Barrels where parallel there would have to be a Sight on each Barrel.

[Ballistics in Scotland]

I agree that the rifling twist makes this tricky, but you can adjust the regulation of a double rifle - up to a point - by changing the bullet weight. Heavier bullets will move the points of impact in the direction of the barrel which fired it, right barrel to the right, and lighter ones will move them in the opposite direction. I think, though I have never heard of anyone trying this, that you could test this fairly accurately by adding discs of plumber's lead sheet or lead filings behind the bullet, separated by a card wad, to increase the weight. They will spin off separately from the bullet, which will head off wherever the barrel was pointing as it departed.

Changing the powder charge won't do much, since although the barrel will recoil and/or flex more with an increased charge, the bullet will leave the muzzle sooner.

[Geraldo]

For you guys overseas, these CVAs weren't regulated in any way. Pedersoli laser regulates, which means the barrels are pointed at the same spot at some distance.

[slumlord44]

According to the CVA catalogs of the day the barrels were regulated. Mine shoots conicals in a pattern rather than a group. A patched round ball works well for me. My hunting load is 90 grains of FFG Triple Seven. I can keep both barrels in a dinner plate sized group out to 90 yards if I do what I am supposed to do. This is fine for deer. It is a hunting rifle, not a target rifle. If you are trying to get 1" groups out of it, it is not going to happen. What size groups are you getting at what range? Mine is a early gun with fixed barrels. later ones had a set screw arrangement at the end of the barrel so you could adjust the barrels so they shot to the same point of aim. Love mine for deer hunting.

[Ballistics in Scotland]

I think they would call laser alignment regulation, with the barrels converging at a distance of their choice, but not adjusted after test-firing. That is better than guesswork or parallelism, but likely to be far from perfect. Why would they go over to that setscrew if it worked without?

A muzzle-loading shotgun can get fairly hot with repetitive firing, and in that situation I wouldn't expect the regulation to work as well as barrels permanently fixed with soldered packing pieces and rib. But for a rifle, you aren't likely to get repetitive deer.

That 48in. twist isn't ideal for either round ball or bullets. I think the best chance of the latter would be a minié, with its peripheral weight distribution. But I got good accuracy with about 48in. twist in an original Bohemian double muzzle-loader, using the Lyman 515139, made for the .50-70 Government. I made a sort of semi-false muzzle, located by a brass pin in the other muzzle.

http://www.midwayusa.com/product/279124/lyman-1-cavity-bullet-mold-515139-50-70-government-56-50-spencer-515-diameter-340-grain-flat-nose

[kens]

Mine is the early one with fixed barrels.
It groups .45acp boolits from a sabot acceptable. but the sights are terrible.
I liked the above idea of 2 folding leaf sights.
Isn't there some Safari Express open sights with multiple folding leafs?

[longbow]

I thought those doubles had two folding rear sights, one for each barrel? Or is that the Pedersoli doubles?

I have always wanted a double rifle and should have bought one of those years ago (either CVA or Pedersoli) but I guess i always feared that poor regulation might be a problem. It seems some are okay and some not so good.

I'm with Ballistics in Scotland on the laser alignment. I would have figured that careful alignment in a jig and using lasers would provide quite decent regulation. But maybe the "proof is in the pudding" and the only way to do it right is successive test firing then re-shimming until it is right... and that would be where the cost of high grade doubles comes from.

With two sights though shouldn't that give good accuracy with each barrel?

Longbow

[Head Shot]

Hello:
A buddy of mine had one of these cva doubles in the 50 cal years ago and i do recall it being said in the instructions the bbls were installed in such a way that they were spose to hit same point of impact at 75 yards.
My buddies seemed to do that and yes his shot best with 100 grains by volume measure of pyrodex rs powder and a 50 cal black sabot with a speer 260gr hp slug # 4581
He killed deer with it without much troubles but later bought a knight mk85 50 cal black powder because he was getting tired of carrying the extra heavy wt around in the woods and normaly shot once anyway so 2nd bbl wasnt really that needed.
Head Shot

[Ballistics in Scotland]

That is interesting, because it seems unlikely that the rifle was designed for a sabot, or for a bullet as light as that, which would be extremely short and dumpy if it had been a full .50 caliber. It sounds like he has accidentally compensated for their inaccurate regulation.

When a double rifle is spreading right barrel to the right and vice versa, it may be possible to use two notches on the same leaf. But trying to use them when the barrels converge too much is likely to be impossibly confusing in a moment of stress. You might very seldom want that second quick shoot, but when you do you will want it extremely badly, and it is going to be stressful.