Double rifle regulation issue

[Shootist43]

Did you buy this rifle new? If used, what did the previous owner say about accuracy? I'm not a double rifle owner but I have considered one. I thought I read somewhere that Chapuis doubles are not regulated and then soldered into position. One barrel is fixed the other is adjustable. Another question, is this one of the guns that was originally sold through Cabela's? They were infamous for having issues. Hope you can get is sorted out.

 

[Tanks]

@Shootist43 it is new he announced it here:

My first double rifle!

Today I have been inducted into your ranks! It's been a lot of saving, planning, shopping, comparing, researching and, finally, buying but I now have my first double rifle, a Chapuis 450/400. I cannot believe that I've taken this step, it's a rifle and caliber that I've been dreaming about...

www.africahunting.com

 

[Shootist43]

In that case I's suggest that get someone else to shoot it. If the groups are equally as bad I think I'd be taking the rifle and the targets as well as the original test target back to the dealer.

 

[Eventually_Africa_Again]

If I am reading this correctly, and you are getting a 4 - 6" spread at 50 yards, the rear sight is the least of your problems.

As @AZDAVE suggests, a photo of a four shot LxR/LxR would be useful.

Another potential fly in the ointment is that the test target was likely fired with the original DGX, not the new bonded bullet. Normally, usually, most of the time that shouldn't make that much of a difference, but then again, sometimes just a new lot of the same ammunition will move groups inches (particularly if the manufacturer changed powders). I have not compared the old and new bullet in one of my doubles. However, the the new bonded .470 regulates well in my Douglas.

And be very careful tackling any screws on that rifle. You need to use a perfectly sized, flat ground driver or you will leave yourself an ugly reminder on that rib for the remainder of the time you own it.

Hello there! Quick question: Can you recommend a flat ground driver? I ask because as I was examining the sight I noticed it is loose, rotating back and forth freely a few centimeters from right to left. I figure and test shots that I do will probably be affected by that so I'd like to get it corrected. Thank you!

 

[Red Leg]

That almost certainly accounts for the dispersion. I use a version of this set that Midway carries. It will fit almost any screw that you will find on a fine gun. It is worth waiting for it to arrive. A buggered screw will haunt you as long as you own that rifle.

Wheeler 89 Piece Professional-Plus Gunsmithing Screwdriver Set

Wheeler Engineering has created a fantastic screwdriver set painstakingly designed to meet the needs of all your gun projects, and at a price that is...

www.midwayusa.com

 

[AZDAVE]

@Red Leg is absolutely correct on the old version of Hornaday DGX/DGS and the new stuff grouping different. In my VC the newer ammo groups are about twice the size as the older version.

At your next range session follow the advice given and get a couple pics and we will help you sort out issues.

Double are different, but once you get things sorted you will enjoy shooting yours.

 

[spike.t]

Did you buy this rifle new? If used, what did the previous owner say about accuracy? I'm not a double rifle owner but I have considered one. I thought I read somewhere that Chapuis doubles are not regulated and then soldered into position. One barrel is fixed the other is adjustable. Another question, is this one of the guns that was originally sold through Cabela's? They were infamous for having issues. Hope you can get is sorted out.

Think you are talking about sabatti doubles not chapuis from cabelas

 

[IvW]

Also I found out that the sight itself is loose, freely wiggling a few cm left and right. Unfortunately I cant lock it dow.

Well now, I would start there before it falls off.....

 

[Shootist43]

spike t, You are probably correct, my bad.

 

[Shootist43]

spike t here is a link to adjusting the regulation of some Chapouis Double rifles. I don't know if there is more than one model that has this feature.

regulating a chapouis double rifle - Search Videos

www.bing.com

 

[chashardy]

Don't get too discouraged. My Chapuis double took some getting used to. I had trouble seeing the front sight with my old eyes, so I added a Trijicon RMR red dot sight. That made a huge difference. It shoots tight groups at 50 yards. If you have never handled a big bore rifle, you may be flinching a bit. I know that I did.
I shoot at the rifle range off a bench to check mine for accuracy but also practiced off sticks and offhand before going to Africa. I will add that my rifle shoots way better with Federal ammo (Nosler partition, Trophy Bonded Bear Claw or Swift A-Frame) than Hornady. I tried Hornady also and did not get good results.

 

[Eventually_Africa_Again]

That almost certainly accounts for the dispersion. I use a version of this set that Midway carries. It will fit almost any screw that you will find on a fine gun. It is worth waiting for it to arrive. A buggered screw will haunt you as long as you own that rifle.

Wheeler 89 Piece Professional-Plus Gunsmithing Screwdriver Set

Wheeler Engineering has created a fantastic screwdriver set painstakingly designed to meet the needs of all your gun projects, and at a price that is...

www.midwayusa.com

Grand! I'm going to order a set, thank you!

 

[Eventually_Africa_Again]

spike t here is a link to adjusting the regulation of some Chapouis Double rifles. I don't know if there is more than one model that has this feature.

regulating a chapouis double rifle - Search Videos

www.bing.com

That's good info!

 

[pamtnman]

What Red Leg wrote: "Another potential fly in the ointment is that the test target was likely fired with the original DGX, not the new bonded bullet. Normally, usually, most of the time that shouldn't make that much of a difference, but then again"
Having regulated a bunch of double rifles myself, it is rare to have one that is already dialed in go to h@ll like yours has. And usually it is something as simple as the hardness or softness of the new bullet compared to the original one the gun was regulated with. Doubles are wonderful tools, giving the gift of an immediate followup shot without breaking the cheek weld or taking one's eye off the prize. But they are often finicky. Once you get a double dialed in (regulated AND shooting accurately), document exactly all of the components you used, and stock up on them as much as you can afford. If it came regulated with one particular brand of ammo, and you have seen the gun replicate what the factory target says it can do, then buy that ammo by the truck loads and hoard it. Even if you only shoot 50 rounds of it, the next owner of the gun (your son, daughter, neighbor, a guy around the globe) will bless you unto the highest heavens for having had the foresight to get all the kit in order from the beginning. Good luck.

 

[norfolk shooter]

I may be a bit late to the party but I found when I first got my double it was doing the same (all shots to the right). I found I was pulling the shots to the right being right handed. Some dry firing exercises helped heaps. It just took time and patience to get used to it and shooting it well

 

[deewayne2003]

If the rear sight is moving centimeters freely = THAT IS YOUR #1 ISSUE TO RESOLVE!

I bought my .470NE second hand and it shoots amazing; only problem was the previous owner was much smaller in stature than I am and the sights were hitting 12" high; Ken Owen who regulated my rifle suggested that before I replace the front sight, that I should make a temporary front sight with modeling clay that I could adjust until it was hitting true to point of aim and then we would know the exact height of new front sight to install.

First group with my first double .470 N.E.

My first trip to the range with my first double rifle taught me a few things and thought I would see if any of you seasoned double rifle veterans would weigh in on my thoughts. Rifle - Sabatti Safari .470 N.E. - Regulation, Trigger job & recoil reducer by Ken Owen of Moscow Tennessee...

www.africahunting.com

I mention this because I have learned loads about open sights from going through this process.

1. THE RIFLE MUST FIT YOU! - I had to have an inch extension added to the stock for the LOP to be correct; and having never had a rifle fitted exactly to my measurements before I can honestly say I was pleasantly surprised by how much less recoil I feel as well as how much better I am shooting this rifle.

2. Sight adjustment , a little goes a long way - I found this formula for adjusting iron sights.

https://en.wikiversity.org/wiki/How...ht#:~:text=D2 = R2(D1/R1,0.077" = 0.582" high.

Point being is that with the measurements I was working with and sighting in at 50yds = 0.012" of sight adjustment resulted in 1" change in point of impact.

So if your sight is moving around centimeters, its no wonder you are having accuracy issues.

Also I noticed that your factory regulation target notes the lot # of the ammo used as 3142497.....

I would check the boxes of ammo that you are shooting and confirm if those boxes of ammo are in the same lot # of production?

If they are they are NOT the same lot# - then you can contact Hornady and give them the lot # from your regulation target and they will be able to tell you if that lot# of ammo was loaded with the old non-bonded or newer bonded version.

 

[One Day...]

I bet this was easily fixed the minute the screwdriver bit arrived

No point in talking about group size until the sights are reliable, right? Just like trying to zero a loose scope

... I found out that the sight itself is loose, freely wiggling a few cm left and right. Unfortunately I cant lock it down.

You likely meant a few millimeters

A few centimeters would be in the order of magnitude of 1" (1" = 2.54 cm). If that had been the case, the rear sight would have fallen off the rib

A few millimeters sideways free wiggle shot to shot is of course plenty enough to open a group...

There is of course a mathematical formula to verify this. You can use the formula used to calculate a front sight height change, to get a sense whether the rear sight shift was proportional to the group size i.e. the shift of point of impact shot to shot. The formula is: amount of error on target in inches multiplied by the sight radius in inches, divided by the distance to the target in inches = front sight height change required (or rear sight drift required).

I cannot say for sure without the data in this case, but let's assume that the rifle has a 20" sight radius (distance between front and rear sight), and let's assume the rear sight shifted sideways shot to shot by 3 mm (0.12"). Mathematically, at 25 yards, this would account for approximately 6" dispersion...

As suggested by Red Leg, before even thinking about anything else, the rear sight needed to be set in place. Until this was done, any other consideration was moot...

Chapuis are well made and generally very well regulated. I would not be surprised that tightening the rear sight lock screw was all it took for this rifle to shoot tight... Correct Eventually_Africa_Again ?

 

[Eventually_Africa_Again]

Hello all! I am very sorry for how long this update has taken to write, we have had a death in our family and it's been hectic. I haven't been out to shoot again, I'm going to try to go tomorrow. We did get the sight fixed though. I'm trying to practice my cheek weld, the last time I went out it beat my cheek up something fierce.

 

[norfolk shooter]

Hello all! I am very sorry for how long this update has taken to write, we have had a death in our family and it's been hectic. I haven't been out to shoot again, I'm going to try to go tomorrow. We did get the sight fixed though. I'm trying to practice my cheek weld, the last time I went out it beat my cheek up something fierce.

So sorry to hear of your loss. Stay strong brother.

 

[crs]

Beretta Double rifle regulation miracle!


This Beretta .45-70 DR with 26 inch barrels was hunted for 10 years by a friend who used only the right barrel to kill deer with his 300 grain handloads at 1600 fps. He killed a lot of deer and some really big ones. After he passed away, I purchased it from his estate and acquired all the historical and technical details. along with 100 rounds of 300 grain handloads and 100 resized and primed brass.
I took it out and killed boar at close range and all seemed well.

Then I shot targets at 50 yards see what it was capable of and learned why the scope was set up for the right barrel; each barrel is sub minute of angle accurate BUT the two barrels were not regulated to suit me. Next step was go through two metal ammo cans of 20 round boxes of commercial 45-70 ammo and select some to test fire to see if there was a happy usable near regulation there.
Today my son and I went to the range and tried two promising commercial loads; Hornady Leverevolution 325 grain ammo and Remington 405 grain JSP ammo.
The Hornady is rated at 2000 fps and was brisk to shoot, but it did not settle in to a neat group.

The Remington 405 grain at 1330 fps produced a 4 shot 2 inch diameter group level with the bullseye and centered 4 inches to the right! Amazed that it could be so easy, I decided to do more work with the Remington 405 bullet since I have a box of 100 ready to load. I also have other .458 bullets to play with (450 grain Kodiak, 400 grain Punch, 450 grain NF, etc).
We stopped right there, made notes on the target and put it away.
Great way to end a day because if this evolves properly, I can cancel the re-regulation project with Aaron and just go hunt the thing!