Are there any double rifle regulation experts here?

[Griz44Mag]

Rather than having to use totally different loads for each barrel - I opted to use the EXACT same load for both barrels. Two rear sights made the process simple and easy.
I don't have to try and remember what to put down the barrel or where to aim.
From 50 to 100 yards - I'm minute of deer (or pig) and it does not matter what trigger I pull to get there.

 

[Ironoxide]

It would be interesting what a couple of well fitting lasers would say when shone from the breach to a distant object!
Seeing as you have split the barrels how about removing the breach plugs and bore sighting them?

No need to remove breech plugs, or even to split barrels. I have a cheap laser bore sight that works surprisingly well if one uses it carefully. The bore fitting (expanding plastic!) plug and the (metal) body has to be inserted in a certain orientation, then rotated. If the laser is aligned right the beam will stay still when it is rotated, if it draws a circle on a target the barrel really points to the centre of the circle. One can then adjust laser alignment permanently with alignment screws.

I use this bore sight routinely. I used it before I split the barrels on a foggy night so I could see the beam very well (it was crossing at 4~5 meters with right barrel also set slightly low). With my current regulation the beams come to a cross around 40m away with both barrels level. This is just a starting point and I already know it is set way too wide.

I'm going to give myself one more shooting session before changing the regulation again as I didn't clean between all shots yesterday.

Also I'm thinking of recutting the crowns.I would have to make some sort of tool to cut the crown without having to use a lathe.I do have one, but as using the lathe locates on the outside of the barrel and I've already established outside of the barrels is cut inprecisely I would like to have a bore-piloted cutter. I already made pins fitting the bores very well that I should be able to repurpose.

One more bit of info about breech plugs for anyone interested in how Pedersoli makes their double rifle barrels. Every double barrel from Pedersoli has a round engraving that looks like leaves going round the barrels. You can see it below well. BTW, the red stuff in left nipple seat is not rust, it is copper anti-seize I use with all my black powder guns.


On the outside breech plugs mate with barrels through the middle of this pattern. Also there are two proof marks on each barrel that are stamped through the mating line. My understanding is they stamped those proof marks like that to indicate "your gun is out of proof if you remove those breech plugs". So I decided not to remove them. I think they are threaded, torqued to spec and then brazed in.

The rifle I was working on is an original English rifle from York. The front sight was a simple bead like that on a shotgun. I replaced that with a taller front sight. That brought the point of impact down.

I tried conicials, balletts and two different sizes round balls and 3 different brands of powder in this rifle. Not to mention various amounts of powder.

I settled on 85 grains of 2F Swiss with a .535 RB and .015" patch.

The right barrel shooting left was due to a small nick at the crown. I believe it was grabbing the patch and throwing it to the left. Once I cleaned up the barrel, the right barrel dropped right in where it needed to.

It took several shooting sessions to get this all sorted out. It got to the point I was really regretting buying it. But, now that I got it figured out, I am very happy with the rifle and very much like it.

I shot it the first time for fun at Friendship a couple of weeks ago in the double rifle match.

Best of luck with your rifle.


Fleener

Thanks for sharing this.

 

[Britsmoothy]

Sounds like they were fitted in a jig with one bore out of alignment.
If so I am struggling to see how with the exception of regrinding the interface of the two barrels it can be redeemed ☹

It could be that with your adjusted set up the shots going wide is a function of recoil having a horizontal influence.

Please please before you recut the muzzles consider bevelling a cresent from the crowning barely visible on the opposite side that you need the ball to impact.

 

[Ironoxide]

Sounds like they were fitted in a jig with one bore out of alignment.
If so I am struggling to see how with the exception of regrinding the interface of the two barrels it can be redeemed ☹

It could be that with your adjusted set up the shots going wide is a function of recoil having a horizontal influence.

Please please before you recut the muzzles consider bevelling a cresent from the crowning barely visible on the opposite side that you need the ball to impact.

Regarding redeeming the barrels I think there is nothing wrong with there being a gap between the flats Pedersoli milled (when I widen the regulation) as long as the gap is fully filled with solder. This is how I "regulated" them wider. I put the wedge at the muzzle and this resulted in almost a 1mm gap mid way where the milled flat is still quite substantial. So I made a straight piece of steel 1mm thick, I tinned it the usual way and clamped it between barrels. Then of course during soldering lots of solder simply dropped through the gap below, but I kept feeding more solder after I removed the flame so it became viscous enough to stay in the gap. I don't worry about it too much. I think it is important the back contacts we'll.

Regarding crowns I'm making a piloted reamer/cutter (one barrel is half a thou bigger, but one reamer will have to do both). So I'll be able to lightly recut the crown removing only a little material at a time. This will give me a crown that is guaranteed straight with the bore. I would like to test it then. Then If it still shoots wide I'll resolder it nearer. Rinse and repeat... When I get tired of soldering I promise I'll try the crescent crown. Once I have the reamer I'll be able to revert it easily if necessary.

 

[Britsmoothy]

Regarding redeeming the barrels I think there is nothing wrong with there being a gap between the flats Pedersoli milled (when I widen the regulation) as long as the gap is fully filled with solder. This is how I "regulated" them wider. I put the wedge at the muzzle and this resulted in almost a 1mm gap mid way where the milled flat is still quite substantial. So I made a straight piece of steel 1mm thick, I tinned it the usual way and clamped it between barrels. Then of course during soldering lots of solder simply dropped through the gap below, but I kept feeding more solder after I removed the flame so it became viscous enough to stay in the gap. I don't worry about it too much. I think it is important the back contacts we'll.

Regarding crowns I'm making a piloted reamer/cutter (one barrel is half a thou bigger, but one reamer will have to do both). So I'll be able to lightly recut the crown removing only a little material at a time. This will give me a crown that is guaranteed straight with the bore. I would like to test it then. Then If it still shoots wide I'll resolder it nearer. Rinse and repeat... When I get tired of soldering I promise I'll try the crescent crown. Once I have the reamer I'll be able to revert it easily if necessary.

I was thinking that if one barrel needs rotating to bring it into alignment with the other the nipple won't line up with the hammer....unless it is a minute amount.

 

[Britsmoothy]

Regarding the muzzle cresenting....
I know that 5 shotguns I have adjusted the POI on was all done via filing across the thin walled muzzles just so one quadrant was shorter by a mere. 030" and hardly discernable.
One heavy walled gun was bevelled more in one quadrant. They all responded exactly how I wanted. I know that was with shot but for legal reasons and busy bodies I can not report on other projectiles.
I'm just trying to emphasise that it is a tiny amount of metal removed!

 

[Dave James]

JJ Perodeau, in Oklahoma, if you look him up, sorry don't have his company info, but he is the go to guy here in the states for regulation

 

[Ironoxide]

I was thinking that if one barrel needs rotating to bring it into alignment with the other the nipple won't line up with the hammer....unless it is a minute amount.

Yes, you're right. There is no way to rotate barrels with relation to one another. As you said the nipple wouldn't align, but also there are square hooks on breeches. Also, I use those flats to align the back. Still I managed to solder one barrel 8 thou forward of another (it is shimmed temporarily at the breech - it will be resoldered anyway). If I added rotation to the whole alignment it would be even more difficult for everything to line up.

Regarding the muzzle cresenting....
I know that 5 shotguns I have adjusted the POI on was all done via filing across the thin walled muzzles just so one quadrant was shorter by a mere. 030" and hardly discernable.
One heavy walled gun was bevelled more in one quadrant. They all responded exactly how I wanted. I know that was with shot but for legal reasons and busy bodies I can not report on other projectiles.
I'm just trying to emphasise that it is a tiny amount of metal removed!

To clarify how it is done. I always thought one opens the crown in crescent shape in opposite direction one wants to move the poi. Removing material from the muzzle face to however deep the crown goes (about 30~40 thou).
However, above (unless I misunderstood) you mentioned shortening the barrel at the muzzle slightly in the same shape. Was the "shortening technique" used because the barrel was too thin walled for there being a crown at the muzzle?
Are both ways interchangeable (crescent ing the crown, vs shortening the barrel slightly at the muzzle)?

Also, do you have any pictures of it done correctly? I may think I know what you mean, but I may be wrong.

I made my crown cutter (pictures below) to cut a 45 degree crown. Then when I cleaned up existing crowns I noticed they must have been out of round because they started cleaning up only after I removed all of original surface.

Then I used a lead ball charged with a grinding compound spinned by an electric drill (through a wood screw) to break the sharpness.

When I was done the result looked really nice, but also the transition from crown to the barrel looked very sharp. It didn't feel sharp, but definitely looked the part so having the cutter to redo it if necessary I resorted to a trip of sandpaper wrapped around my finger. I counted the number of sandpaper strokes and moved the barrel around by the same amount so I think I achieved pretty good co centricity. However, human hands are not perfect so I may already have a slight crescent there and not know it. When I go to shoot it I'll take a bit of sandpaper and if I have poi shifted unexpectedly I'll remove a tiny bit of material as Britsmoothy describes. I'm pretty certain I'll have to make two more cutters anyway. One 90 degrees to clean up the muzzles faces and another one shaped differently than straight 45 degrees. Maybe something funnel like?

Anyway, here are few pictures from making of the cutter.
Turning a piece of water hardening steel rod on my "precision(Chinese)" lathe I have a large 2 ton made in Poland lathe that I usually rough cut stuff with, because it is much more powerful. Then I usually finish the part on the Chinese mini lathe. I normally use a 3 jaw chuck, but I decided to turn this properly between centres.
Then there is a blank done. The pilot fits really nicely. As one barrel is slightly (hal ~. 8 thou) larger it is a slight friction fit in one and a sliding fit in the other. No wobble detectable.

Then cutting teeth were milled. I never made a 4 tooth cutter before so I made it cut in counter-clockwise direction by mistake... No worries. Precision is most important.

Then after hardening (before tempering)

And final picture below being held by a threading handle. The shank is round, but forces involved are so low the wrench was holding it fine.


Then there is the muzzle cut with it. You can also see my high tech temporary front sight.
On the picture the crowns were cut with the cutter about 5 thou deeper than originally. Then the lead ball lap was used, followed by a little of sandpaper wrapped finger. I also stoned muzzle faces.

 

[Britsmoothy]

Excellent work.

Yes , opposite side, remove material from the opposite side of DESIRED direction.
Yes, some thin walled barrels are simply filed across but bearing on one quadrant again opposite to the desired direction.
On a side note, I take the opportunity to observe now all old English shotguns I come across at the muzzles and some do indeed show that this practice has been applied.
Sorry no I did not take photos. In the past if I mentioned it I thought I was going to be burned on the stake!
It is difficult for many to grasp.
Many don't appreciate that with velocity very subtle things have influence. While many understand the detrimental effect a damaged crown may have the same folk miss that there could also be a useful application....not from damaging a crown no but by a measured approach or adjusting!
One way to explain the very subtle influence is how much a shotgun choke can influence patterns massively but the actual constriction is a few thou!

Some believe it is due to the early venting of gas on one side. I see it differently, I see it as an increase in drag on one side or a quarter of the muzzle circumference.
I am really selling this as though it will definitely work. IT MAY NOT, but please while it's all torn down and an opportunity exists to practice the process of elimination principle give it a shot. " Give it a shot", see what I did there .

 

[Ironoxide]

Talking about old English shotguns it just happens that I have one in my gun safe It is no Holland&Holland, but my shotgun was made by "Stevens of London". It is a 20 ga muzzleloader with twist steel barrels. I haven't shot it yet so I don't know the pattern. I had a close look at the muzzle. There is one area that looks like it was very slightly relieved it it on the right barrel upper-left quadrant. I took multiple photos, but it is very difficult to capture. It may be a dinged muzzle repair or it may be exactly what we're discussing. Here is the best picture. That relieved area on this picture can be seen if you know what to look for. The right barrel on this picture looks like it has almost a corner. If you just look at the muzzle you can't see it. I wonder if that is it.


Coming back to my double rifle. I took it to the range, but I had very little time. I could get in only few shots. I did remove a little material (20 strokes of 600 grit sandpaper). It is such a small amount it is essentially invisible. The next shot wend even wider. So I removed double the amount from the opposite side. Subsequent shots went same as prior (before any sanding). Conclusion : I probably removed too little.

I'll try again after soldering barrels with nearer regulation.

 

[Britsmoothy]

Talking about old English shotguns it just happens that I have one in my gun safe It is no Holland&Holland, but my shotgun was made by "Stevens of London". It is a 20 ga muzzleloader with twist steel barrels. I haven't shot it yet so I don't know the pattern. I had a close look at the muzzle. There is one area that looks like it was very slightly relieved it it on the right barrel upper-left quadrant. I took multiple photos, but it is very difficult to capture. It may be a dinged muzzle repair or it may be exactly what we're discussing. Here is the best picture. That relieved area on this picture can be seen if you know what to look for. The right barrel on this picture looks like it has almost a corner. If you just look at the muzzle you can't see it. I wonder if that is it.
View attachment 83099

Coming back to my double rifle. I took it to the range, but I had very little time. I could get in only few shots. I did remove a little material (20 strokes of 600 grit sandpaper). It is such a small amount it is essentially invisible. The next shot wend even wider. So I removed double the amount from the opposite side. Subsequent shots went same as prior (before any sanding). Conclusion : I probably removed too little.

I'll try again after soldering barrels with nearer regulation.

That is exactly what I am referring to

 

[Ironoxide]

This time I resoldered the barrels differently. I've prepared the tinned flats with steel wool so they were perfectly flat. I removed the flux with isopropyl alcohol and I inserted both barrels into the hooked breeches on the stock. I clamped them in two places with welding clamps and I lifted them from the stock. Then I put my bore fitting pins in both bores and I used a cast iron surface plate to and a piece of precision ground parallel to align both bores in line. This was taken just before soldering:


As you can see the muzzles are not clamped and they were not soldered. The alignment was set exactly as it came out of the factory, but muzzles were left "flapping in the wind" so it is possible to tweak them.

I made this device for the purpose


Screws aligned at 45 degree angle are there to spread muzzles apart precisely. To set adequate setting a thickness gauge is inserted between muzzles. Then the device screws are tightened (gently, not to marr barrels - unfortunately I didn't have brass screws).

Also 45 degree screws double as a poor man's front V notch sight. This is how it looks in use


So far I had time for only few shots, but it looks like the desired regulation will be only 0.3mm (12 thou) wider than factory.

To illustrate better how weird this result is I'll say that 12 thou extra separation at the muzzle should equal to only one inch wider poi at a 50m target, but it moves the poi by a lot more!

 

[LawrenceA]

Got a CVA Express that needs regulating.
Can't wait to find see how it turns out.

How much difference did 12 thou make?

 

[Ironoxide]

Got a CVA Express that needs regulating.
Can't wait to find see how it turns out.

How much difference did 12 thou make?

Bear in mind I only fired 4 shots (2 before, 2 after) as daylight was almost gone. And today it is raining all the time. So I'll test more when weather improves.

Answering your question(from memory, give or take an inch) . Before I started with the barrel (let's call it setting 0 - barrels crossing at 4.5m). Shots with 75 grains of powder were cross-eyed by around 6~5 inches at 30m. Yesterday before I fired those 4 shots I set it 0.75mm(30 thou) apart and it was shooting about 3.5 inches wide. Then I set it to 0.3mm(12 thou) and final two shots looked to be spaced exactly the muzzle distance apart (parallel). Left shot was almost an inch lower though.

So those 12 thou difference appears to move the points of impact from crossing by 6~5 inches to parallel. Or if we consider one barrel in separation 2.5~3 inches movement at 30m. If the gun was held in a vice the poi should move by 7.4mm (a bit over 2/8ths of an inch) only. The rest is either shooter error or the famous "double rifle recoil impulse torquing the gun to the side".

Can we judge it after 4 shots? I may have flinched (but it definitely felt I didn't). I save my final judgement until I shot it a lot more.

About your CVA, how wide or crossed is it shooting now? Perhaps you can achieve the desired regulation by varying the load or projectile weight (including wads etc).

 

[LawrenceA]

From memory the left barrel is about 1-2 inches lower and about 4 inches to the left at 50 yards.
Supposedly I need to load the right barrel heavy and the left light.
Honestly dont want that.

Can't remember the loads I played with. I kinda gave up with disappointment.
But it is almost time to try again

 

[Ironoxide]

From memory the left barrel is about 1-2 inches lower and about 4 inches to the left at 50 yards.
Supposedly I need to load the right barrel heavy and the left light.
Honestly dont want that.

Can't remember the loads I played with. I kinda gave up with disappointment.
But it is almost time to try again

This is interesting. I'll mention it just in case as you may have already done it. It is worth trying different ball sizes if you can get them (best are self cast and weighted, if you weight store bought balls you'll know why). Also different patch thicknesses and more/less lube (less often shoots better). It is worth trying cleaning between shots to help fit tighter patch/ball combo. If the patch/ball requires frequent impacts all the way down the (wiped clean) barrel it is too tight in my opinion. If you just press and it slides down with heavy resistance it is only a smidgen too loose,but may do if a very slightly thicker patching can't be had. If it is difficult to start, but once started your patch/ball slides freely down the bore check your crown. It may have sharp transition that may benefit from _very_ light sanding. Finally about patches, I always measure patches compressed. This is done with a micrometer, once little click clutch engages don't stop. Grab the spindle and turn it further to compress it. Make sure to always use similar force. It is an imprecise method, but gives one some idea of patch thickness when compressed.

Finally, after you've tested everything I would put the gun away for few months (as you've done) and redo a lot of testing. After all this if you still feel it needs mechanical regulation I would start with the method Britsmoothy mentioned (muzzle shaping). It is a lot less work than desoldering etc. If my set of barrels wasn't due a refinish I wouldn't have decided to do it.

Oh, and one more thing. If one barrel shoots to the side how about moving the front sight for the point of aim to be right in the middle and dropping te load slightly (5~10 grains less)

I hope this helps.

Regarding my regulation I went to the range yesterday evening and I confirmed 12 thou wider shoots parallel with 75 grains. However, I also tried "baseline" with muzzles touching as they were/should've been out of the factory. Previously loads over 100 gr were shooting smoothbore sized "groups". Now I'm getting a lot better accuracy with high loads too. I have to assume muzzle recrowning as well as much better alignment at breech faces is responsible. It would be quite funny if at the end I decided to set the "regulation" to factory spec Two issues that remains however with the factory setting are that the left barrel shoots low (easy to correct by lifting it 15~20 thou higher) and both barrels shooting significantly left (front sight has to be moved 50 thou to compensate!). If I don't find a bend further down the line I'll probably compensate it with a front sight.

Next step will be to solder it in the desired regulation and shoot (yesterday's tests were with the screw contraption maintaining muzzle positions).

 

[fleener]

Do you find that the barrels move when you shoot it with you jigs on it?

Fleener

 

[Ironoxide]

Do you find that the barrels move when you shoot it with you jigs on it?

Fleener

The jig puts a bit of extra weight at the muzzle. It must have some effect, but I didn't notice any change when shooting with it vs without (with muzzles soldered).

I think I now have a good idea where the regulation should be (between the factory setting and 12 thou extra separation depending on which load will group best with the ribs on plus left barrel up to 20 thou higher).

With shooting left, it must be a result of a bend or perhaps the bore is not exactly centered in the barrel. I think I'll just move the front sight accordingly. It'll not be as pretty as I would like, but I can live with it. It is such an important bit of info I'll be starting a separate thread to discuss it as the erroneous explanation which I too believed in deserves to be straightened out!

In my search of double rifle literature I found a very interesting article in the "Field" magazine from December 1, 1888. The article is a report of an experiment that proves the true reason why double rifles have to be regulated for barrels to cross (spoiler - it has nothing to do with recoil).

 

[Ironoxide]

I've got to the point where I know what regulation I want. I decided to go for 6 thou wider than factory. I also decided to soft-solder the entire length of the barrels as well as ribs. Then finish with (steam)rust blue.

Here are few pictures from the lower rib laying process.

This youtube video was very helpful in how to do it:

I plan to shoot it as a final test after I do cleanup after laying the lower rib (before top rib is soldered). Then if it shoots ok to solder the top rib. If soldering the top rib changes things I may use the muzzle crescenting to push it the last little bit necessary.

However, before I finish I noticed a bit of a problem. During tinning of the barrels for rib laying I unfortunately tinned few millimeters too wide in few places. Before rust bluing I need to get rid of that tin. Does anyone have some clever method to do it without having to melt it again? I was planning to sandblast the barrels with sharp media then to glass bead blast to uniform the surface. I'm not sure if sand blasting removes solder. I may have to do a test on another piece of steel to check.

Unless someone has an easier method of removing solder from steel?

 

[fleener]

https://www.amazon.com/Swpeet-Polis...ewelry+polishing+dremel&qid=1625423367&sr=8-8
I have used something like the above with good sucess. These will peal the solder right back and not harm the steel as long as you dont get heavy handed.

Easy way to clean it up.

Fleener