Is there a common explanation for the left barrel consistantly shooting high with every load? Is there a common mistake in shooting form that I may be making that would cause it? The rifle is a Chapuis 9.3x74 factory regulated with RWS 247 gr. bullets which means it was regulated with unobtainium. I've gone through several dozen load combinations and factory loadings and have my left/right regulation about on with Hornady 386 gr. Interlocks but every round and load I've shot the left barrel is 1 to 3 inches high and gets higher as velocity goes up. The test target showed the left barrel about 1/2 inch high.

I would try a bullet closer in weight to the original regulation load. A number of mfg's make a 250gr 9.3 bullet.

Thanks Ken, I tried 3 powders and 2 primers in both Norma and Hornady cases with Nosler 250gr. Accubonds figuring that would be close enough to the 247gr. RWS to work. I never could get the loads slow enough to stop crossing. I got to the bottom end of the charts on all 3 powders (RL-15, H4350 and H380) and was still crossing. By the way, the rifle came through WLM but I bought it new from a dealer in Minn.

OK, never mind I didn't realize you had already tried the 250 gr bullet. What is the overall size of the group with the left barrel shooting 1" high.

I was getting a group with about a 2 to 3 inch spread when the left barrel was 1" high. As I close the spread up to about the width of the barrels the left barrel goes up to about 2 1/2 to 3 inches. Seems to be pretty consistent with most loads. I'm using a scope but it is a light weight one with the Chapuis/Recnagel rings.

How does it shoot with the 286's as far as crossing?
I would bet your rifle was regulated without a scope. Have you tried these loads using just the iron sights?

I have a smaller caliber double that went absolutely nuts when I put a small scope on it. Took off the scope and it went back to just over MOA.

I've worked up a load with 64 gr. of IMR 4831 that is just about right as far as left right goes. Quite honestly even with my $6,000 post catarac eyeballs I still need a scope to shoot with any precision. When I shoot with the irons I can't tell if the spread is me or the rifle.

Bayou

2 questions.

Are you using a Black 8" circle and are you aiming for the centre - ie the 10 Ring ?

Also, what distance are you shooting at ?


If so, suggest you put a white 1" circular sticker at the 6 and 12 o'clock positions of the black, right where it joins the rest of the target.

It makes it much easier to aim open sights at 50 yards and virtually guarantees the same POA - Point of aim - each time and so nearly eliminates one variable - ie you.

Just my HO.

Thanks 500N. Haven't tried that. The target is a black 6" circle with an orange 1" center dot. I'm shooting at 50 meters and the white front bead just about covers the 6" circle.

Have you shot it using factory ammo- RWS 247 gr. bullets?
While pricey, it could tell you if it is regulated with or without the scope.

So far I haven't found any RWS ammo. I've got several people looking for me but no luck yet. I'd just like to get a couple of rounds to chronograph so I would have a definite velocity target to shoot for.

quote:

Originally posted by BayouBob:
Thanks 500N. Haven't tried that. The target is a black 6" circle with an orange 1" center dot. I'm shooting at 50 meters and the white front bead just about covers the 6" circle.

OK, well what you are doing covers the same reason.


I will say that having the "dot" of any colour at the 6 o'clock position
generally means that the whole 6 OR 8" Cirlce nestles in the V notch
of the rear sight.

Therefore, IF you drop the gun at all, the cream or white outside the black circle shows up very quickly (And therefore that you are off target slightly). In addition, I find it easy to bring the gun up and when all the the cream or white outside the black circle has gone, I know I am on target.

Then all I have to do is make sure that the foresight is aligned properly.

Anyway, good luck.


PS - Try adjusting the seating depth of the bullets. SOMETIMES it makes a difference.

.

quote:

Originally posted by BayouBob:
I tried 3 powders and 2 primers in both Norma and Hornady cases with Nosler 250gr. Accubonds figuring that would be close enough to the 247gr. RWS to work.

I guess by 247 RWS bullet - it means it was regulated with KS (kegelspitz aka cone point) bullet. Geometrically it is a quite specific bullet (see pic) - no tail with long parallel sides with sharp passage into cone:



Accubond is geometrically opposite - boat tail, shortish parallel sides...

I don't know if this is the case, however it sticks out - and sometimes this is enough for a double to make an objection...

P.S. Factory is stating 2460fps for 247gr - I haven't measured it in mine hovewer so far the RWS factory stated velocities of other bullets (TUG) converges with my measurements from my Merkel within 20fps.

Mouse

Agree. Bullet shape can certainly make a difference. Not sure if it is in this case but definitely worth considering.

.

quote:

Originally posted by BayouBob:
Is there a common explanation for the left barrel consistantly shooting high with every load? Is there a common mistake in shooting form that I may be making that would cause it? The rifle is a Chapuis 9.3x74 factory regulated with RWS 247 gr. bullets which means it was regulated with unobtainium. I've gone through several dozen load combinations and factory loadings and have my left/right regulation about on with Hornady 386 gr. Interlocks but every round and load I've shot the left barrel is 1 to 3 inches high and gets higher as velocity goes up. The test target showed the left barrel about 1/2 inch high.

If I interpret Graham's book correctly, that is also an indication of one barrel showing more wear than the other.

Thanks Mouse, The long bearing surface on that bullet is probably closer to the bearing surface on the 286 gr. Hornadys. The Hornady looks like it will shoot okay as far as the left right spacing goes. I may have to find a compromise load that keeps the bullets reasonably close in point of impact. It's good to know that the published velocity is probably close to real world numbers. That is typically not the case with American companies published velocities.

Try altering your shooting form. It's very possible you're canting the rifle sideways a bit.

Bayou
Have you given the bores a really thorough cleaning? Maybe a guilding metal buildup that is worse in the left bore than in the right?

I seem to recall someone here having a similar issue that was cured by a good cleaning.

Thanks Jorge, I bought the rifle new in the box 3 weeks ago and have about 200 rounds through it so far. This afternoon I'm going to squint real hard and try to shoot some consistent pairs with the open sights and see if I can tell if the scope may be affecting the regulation. There are 159 pages of topics on the Double Rifle forum and some of the topics go several pages of posts. I went through all of them before I started asking questions just so I wouldn't sound too stupid. I really appreciate all the suggestions.

MACD, I've given it 3 light cleanings and one really deep "soak and scrub" cleaning. I don't have access to a bore scope but it seems to be pretty clean.

Sorry, didn't realize it was NIB. What MAC says might also be something to look at. As far as scrubbing, have you tried one of the good copper removing products like Wipeout or Montana Extreme? Mike also brought up a good point withe the canting issue

quote:

Originally posted by BayouBob:
Is there a common explanation for the left barrel consistantly shooting high with every load? Is there a common mistake in shooting form that I may be making that would cause it? The rifle is a Chapuis 9.3x74 factory

regulated with RWS 247 gr. bullets which means it was regulated with unobtainium. I've gone through several dozen load combinations and factory loadings and have my left/right regulation about on with Hornady 386 gr. Interlocks but every round and load I've shot the left barrel is 1 to 3 inches high and gets higher as velocity goes up. The test target showed the left barrel about 1/2 inch high.

BayouBob, First off in your post above you list a 386 gr Interlock! I assume that is a typo and you meant 286 gr!

You didn’t say but I assume you are right handed, and shooting iron sights, if not take the scope off and try it without. If shooting with a scope the cross hairs may not be level with the barrels, so that using the cross hair to indicate the barrels being level may be your problem. It takes very little canting to make one barrel shoot higher than the other on a S/S double rifle!

That being said, the left barrel shooting only 1 inch high at what I assume to be 50 yards, is likely only that you are canting the rifle a little when shooting and is nothing to worry about! If you are shooting at 100 yards I wouldn’t worry about it at all. If the composite groups of both barrels are under four inches at 50 yards with the aiming point close to the middle of the composite group of two shots from each barrel,from a cool barrel set, using the 286 gr bullets you have little to worry about!If at 100 yards that is very good!

All groups worked up in a double rifle should be shot from cool barrels, and fired rt,lft, rt left. The rifle is regulated to be fired in the field from cool barrels, and likely no more that four shots, two from each barrel. New guys are prone to shoot group after group without letting the barrels cool back to ambient temprature, then wounder why their groups are all over the target!

One other thing that can exaggerate the effect of shot placement on the target is resting the rifle directly on sand bags or on sticks, or GOD FORBID shooting in a lead sled! The double rifle should never touch anything but your hands, shoulder and face, when shooting!

I’m sure if you check your canting, and rest system, the groups will level out! I don’t see a problem that a slight change in shooting procedure may fix!


As far as the factory regulating with the 247 gr bullet IMO that was a mistake on their part, and is done by many makers. I have a Merkel 140E-1 double chambered for 9.3X74R that was regulated with the 247 gr bullet as well, but shoots 286 gr bullets just fine! The 9.3X74R doubles will usually shoot the 286 gr bullet very well in any case. Tony has a Chapuis 9.3 double and is shoots like a target rifle with 286 gr bullets of about every make!

Again IMO, any 9.3X74R double rifle should be regulated with a 286 gr bullet! IMO you should find a good load with the 286 gr and forget the lighter bullets! I shoot nothing else in my two 9.3 X74R double rifles! I’ve found the loads in the Nosler data for 4064 powder works best in my rifles!

Good luck, and keep us apprised of what you find!


.....................................

Thanks Mac, Yes, 286 Hornadys. I spent quite a while using a scope leveler to make sure the rifle wasn't canting when I shot but I'll check that again. I'm sitting at a bench with my elbows on the bench and my front hand resting on the bag. My position is upright and the rifle is only touching my hands and shoulder. I shoot no more than 4 shots before putting the rifle down to cool for 10 minutes or so. After 4 shots the barrels are uncomfortably warm anyway. I fire the left barrel each time as quickly as I can get back on target. (I have tried shooting the left barrel first but that made no difference.)

I was a little surprised that the rifle was regulated for a round that is so hard to find in America since it was made for the US market. I'm shooting at a 6 inch bull at 50 meters and all the shots stay inside it. Except for the 2 when I doubled the rifle; that will spread your group out! A deer or a hog at a reasonable distance won't survive the experience the way I'm shooting now but I'm pretty sure the rifle is capable of doing better. I may try to figure out a way to check while I am at the bench with a bubble to see if I'm canting the gun. After I had eye surgery my archery dealer observed that I was unknowingly canting my bow when I shot.

On the positive side, I'm having a ball shooting the little rifle and having something to work out gives me an excuse to go to the gun club every afternoon and make some noise.

The Chapuis's are very forgiving rifles and will usually accept many loads giving acceptable results.
What is your group size for 4 shots at 50 yards, 2 from each barrel?

One other suggestion to help your shooting. Put two targets up at the same time and line them up side by side. This will allow you to fire off two rounds as quick as you can without having to stop and glass and find out where each bullet is hitting.

Remember, this is not a bolt rifle. 2 inch groups at 50 yards is perfectly acceptable as this is better than 99.99% of the shooters are capable of in the field.

quote:

Originally posted by Snowwolfe:
The Chapuis's are very forgiving rifles and will usually accept many loads giving acceptable results.
What is your group size for 4 shots at 50 yards, 2 from each barrel?

One other suggestion to help your shooting. Put two targets up at the same time and line them up side by side. This will allow you to fire off two rounds as quick as you can without having to stop and glass and find out where each bullet is hitting.

Remember, this is not a bolt rifle. 2 inch groups at 50 yards is perfectly acceptable as this is better than 99.99% of the shooters are capable of in the field.

..................Absolutely!

If you bought your new Chapuis from Dale it probably was regulated with the scope on it. I had similar problems with mine until I brushed the crap out of the barrels. I used a brass brush with a patch wrapped around it - the brass poked thru the patch and the patch picked up the loosened crud. I settled on 286gr PRVI bullets and consistently get within 4-inch circle at 75 yards.

My 71-yr-old cataract-operated eyes need the scope altho I do only a little less well without it.

Four inches at 75 yards (3 from each barrel) is enough to make me happy. The bullets from each barrel are easily within 1-2 inches of each other.

It took me a lot of rounds to get to this point and I suspect much of it was my slow learning curve as well as barrel crud.

Thanks Oxon, I didn't buy it from Dale. It took a circuituous route from France to me. I have given it a pretty good scrubbing with the brush and solvent so I think the bore are fairly clean. I suspect that a lot of it is just my getting used to shooting a double rifle right. When something doesn't go perfect I usually figure the problem is me, and usually I'm right!

Should have stayed home today. 100 degrees and about 111% humidity made for a miserable shooting session. I did re-check the level on the scope and made a tiny adjustment. At 25 meters both with and without the scope I was shooting left barrel about 1" high. At 50 it was a faily consistent 2" high both ways. I'm pretty close to being regulated for left/spread with 64 gr. of IMR 4831. My shooting glasses stayed fogged up today so my results weren't conclusive. I'm probably going to try at least one more powder just to see if it makes any difference. Thanks for all the advice; I'm working my way through all of it.

If you're shooting 1"-2" high at 50 yards and acceptibly consistent left to right, you have a great shooting gun that only needs the sights adjusted or your aim picture adjusted.

That sounds like an awfully good shooting gun to me. I'd take a 1"-2" group pattern all day long at 50 yards as long as the horizontal is also only 1"-3".

Take it and run, Kill lots of game, and reap the rewards.

Double rifles are not creatures of perfection.

Mike

Thanks for all the advice. I did re-check the scope level at the range and tweaked it a little. My last 2 composite groups are 1 1/2 inches left to right and the left barrel 1 1/2 inches high at 50 meters both with the scope and with iron sights. I'd post a picture but I haven't figured it out yet. I'll still keep playing with powders and bullets to get a tiny bit better but this will kill anything that walks by. I'm ready to move back to 100 meters and see what she will do. Thanks a lot to Ken for the visit; great guy.