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NitroXAdministrator
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Double Rifles and Regulation
      #376602 - 09/05/23 10:55 PM

I've posted something like this before but just typed this again.

Any corrections or additions?

***

Regulation is about bringing the point of impact of two barrels together or parallel at a certain distance. For example, a side by side, might have it's barrels adjusted or regulated to impact two barrels points of impact approximately 30 mm apart at one hundred metres, inches, yards etc. Right barrel to the right, left to the left.

An under and over similarly, the top barrel a little higher than the bottom barrel at a given distance.

Some people incorrectly believe double rifles are regulated to cross at a certain distance.

This is in theory. Actual practice may not be theory.

Point of impact depends on how long a bullet is in the barrel and any initial recoil movement. Physically a side by side might move upwards and to the right with the right barrel. Upwards and left with the left. The bullet while in the barrel might experience some of that movement.

Of course the projectile, bullet weight, load, velocity etc affects regulation. The warming and barrel movement from heat expansion of the first shot barrel, impacts on the impact of the second barrel. The Heym Gunmakers regulator said to me they use a standard of a seven second delay between shots when regulating. More or less time might affect the regulation impacts as the heat expansion might be different.

The weight and balance of the double rifle can also have an effect. The double rifle might be regulated with open sights, a dot sight, or a specific scope. The weight of a scope or change in balance might affect the regulation.

Sighting or shooting a double rifle should be done with the forehand resting on a rest, not the forend or barrels directly resting on a rest . It simulates more a standing shot. How the double rifle moves under recoil affects regulation bullet impact placements.

Regulation is done with the two barrels temporarily fixed in place. And temporary wedges used to alter the angles between the barrels, left and right, up and down. Test shooting is done until the wedges are right. Then the barrels are affixed together, wedges fixed in place, rib soldered in etc. One of the reasons double rifles can be so expensive is this hand regulating and test shooting. (Engraving and brand name, other big expense factors. Hand fitting is not cheap either.)

Unless the double rifle has non affixed barrels. My Tikka/Valmet 512 under and over double rifle has a gap between the barrels. A wedge at the front to adjust for right and left movement. Another wedge half way along for adjusting up and down the barrels, changing the angle between them. I regulated my 9.3x74R barrels with the 286 gr bullet and chosen hand load to be about 25 mm apart at one hundred metres. Similar to the muzzles. With the scope attached.

A side by side would be the opposite. The midway wedge to alter left and right. The front wedge for up and down. The Blaser S2 was another drvwith barrel gaps, unaffixed barrels. The Baikal is another.

Regulating loads. Owners talk about handloading and "regulating" their double rifles. This terminology is incorrect but acceptable. Unless they are moving the barrels, what they are actually doing is trying to duplicate a regulating load. They are not regulating their rifle by tinkering with handloads.

Regulation and double rifles are not exact sciences.

Some rifles will still shoot ok if say the left barrel barrel is shot first instead of the usual right barrel. On a side by side. Some demand the right barrel first.

Some will regulate still with different loads and bullets. Some claim a 75% rule works, use eg the same powder charge in a .450 as used for a 480gr/500 gr bullet, but for a 75% weight bullet, a 350 gr and it will also work and shoot to regulation ? In a .375, 300 grs and 235 grs. Trial and error is the rule.

Some rifles might regulate with the open sights and a scope. Don't depend on it though. A lighter small dot point sight might work better for an express sight regulated rifle.

The main thing, is to have a double rifle shoot well for regulation with an effective bullet and an effective cartridge for the game desired. And the ability to shoot it well, at close range, in a hurry. Running or still shots. All the extras are pluses.

Trial and error until hopefully the desired result or an acceptable result is achieved. Trial and error supersedes theory.

Lastly, sometimes an existing rifle just has to be sent back to the factory, or a very good double rifle gunmaker/gunsmith and bevre-regulated. The rib removed, the barrels separated, the whole regulation process repeated. Not a cheap option. I remember one gunsmith charging $5000 for this. I think a Brit premium brand would charge a multiple ?

Have fun. It's not some crap plastic stocked mass produced bolt action.

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

Edited by NitroX (10/05/23 08:01 PM)

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NitroXAdministrator
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Re: Double Rifles and Regulation [Re: NitroX]
      #376605 - 09/05/23 11:56 PM

Some editing needed.

Second editing and additions done.

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
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Edited by NitroX (10/05/23 08:01 PM)

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degoins
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Re: Double Rifles and Regulation [Re: NitroX]
      #376608 - 10/05/23 02:29 AM

"Trial and error is the rule."

That pretty much sums it up in my limited experience. Good read.

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85lc
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Re: Double Rifles and Regulation [Re: NitroX]
      #376609 - 10/05/23 02:51 AM

John,

Thanks for the info. I am one that always thought that double rifles were regualeted to point of aim t 70 yds or so and that in fact would cross beyond that distance so that theoritically, at 150 yd the right would be 1.5" to left of the left barrel, still within a minute of an animal's sweet spot.

The doubles that I have shot seem to do well for 4 shots (2 per barrel) and then accuracy falls off somewhat util the barrels cool down.

The only comment I would make is to add the word "hundred" as follows: I regulated my 9.3x74R 286 gr load to b about 30 mm apart at one "HUNDRED" metres. With the scope attached.

This probably doesn't belong here but the front trigger on my Sempert & Krieghoff O/U fires the lower barrel. I always thought the front trigger fired the upper barrel. I found out mine shot that way when first shooting it. I only loaded the top barrel and no bng. Several trys without suggess, I loaded the bottom barrel and pulled the rear trigger and bang. Opening the gun, I found the top barrel had fired. Closing and pulling the front trigger, the rear barrel fired.

Is it set up that way because the lower barrel is more in line with the shoulder and therefore has less rise that it may be more accurate? Any thoughts?

--------------------
RB

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kuduae
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Re: Double Rifles and Regulation [Re: 85lc]
      #376613 - 10/05/23 06:16 AM

Quote:

This probably doesn't belong here but the front trigger on my Sempert & Krieghoff O/U fires the lower barrel. I always thought the front trigger fired the upper barrel. I found out mine shot that way when first shooting it. I only loaded the top barrel and no bng. Several trys without suggess, I loaded the bottom barrel and pulled the rear trigger and bang. Opening the gun, I found the top barrel had fired. Closing and pulling the front trigger, the rear barrel fired.
Is it set up that way because the lower barrel is more in line with the shoulder and therefore has less rise that it may be more accurate? Any thoughts?


Traditionally, nearly all continental European two trigger over-unders, double rifles, shotguns and combinations, are set up so the front trigger fires the lower barrel. They all share the same or , at least, very similar actions and most were available on order with interchangeable barrel sets to cover all types of hunting. On break open o-us the lower barrel is closer to the hinge. So firing the bottom barrel puts less stress on the lockup of the action. That’s why the high pressure rifle barrel on combinations is usually placed below the shot tube. But even on double rifles and shotguns the “first” barrel is used far more often in hunting than the second reserve shot. So, just like side by sides are usually set up to fire front trigger = right barrel, rear = left, over unders are built front = bottom, rear = left. Additionally, double rifle and combinations usually have the primary rifle barrel trigger fitted as a single set trigger. Such a set trigger is much easier to be pushed forward for setting if it is the front one, with plenty space behind to allow for the thumb. To me, pulling the reartrigger first and then reaching out for the front one is much slower than simply letting the finger slip back after the first shot. The only real reason I know for using the rear trigger first is an old and quite worn double rifle: As the right/bottom barrel has usually seen much more use, the originally second one may be the more accurate one. Only then it makes sense to use the better barrel for a carefully aimed first shot and save the bum barrel for hasty emergency use.

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NitroXAdministrator
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Re: Double Rifles and Regulation [Re: 85lc]
      #376622 - 10/05/23 07:11 PM

Quote:

Thanks for the info. I am one that always thought that double rifles were regualeted to point of aim t 70 yds or so and that in fact would cross beyond that distance so that theoritically, at 150 yd the right would be 1.5" to left of the left barrel, still within a minute of an animal's sweet spot.



I have been told American customers often ask for barrels to cross. Euro customers prefer the barrels to shoot parallel. Which the gunmaker thought proper.

What 'your' particular rifle does? Let's say my rifle is shooting impacts one inch apart at a hundred yards. Left and right barrels to L and R. Are they still parallel at 150 metres? At 200 metres? Or crossing somewhere?

Let's assume they magically stay parallel. 1 inch at 100 yards apart. Let assume 1 MOA groups from each barrel. Magic! . So theoretically at 100 yards two bullets, one from each barrel could be touching. Or 2 inches apart. 2x 1 MOA side by side. Combined a 2 MOA grouping. In theory.

Let's go parallel to 200 yards. 2 inches apart. 2 MOA groups each. Similar result, combined 4 MOA group.

Make the original individual barrels accuracy 2 MOA. At one hundred yards, one inch apart, the impacts might cross like a Venn diagram. Creating a 3 inch wide dual group. At 200 yards the groups are 2 inches apart, but each group is 4 inches. combined group is 6 inches wide.

If crossing the combined group will be more mixed. Unknown, many variable factors.

All very theoretical!

Trial and error.

If one has ones "regulating" load say at 100 yards. Shoot 1xR, 1xL. Reload, repeat but say on a second target. Keep track on which is the left barrels and right barrels.

Superimpose the two targets to get 2x 2 shot groups. One could keep shooting each barrel, on new targets, 3, even 5 shots from each barrel. Would be revealing on each barrel's accuracy. How effective the regulation is. How both the accuracy and regulation changes as the barrels heat up.

Give your shoulder a rest. Let barrels cool down. Repeat. Repeat until you see stars ...

Do similar at 150, 200 yards. If 200 yards is encouraging, try 250, 300 ! After all my 450 NE's express sights go to 500 yards! Might need a very big target for groups ... A barn door?

Definitely shoot at 50 yards as well. Might rebuild confidence after shooting at 200 and 300 yards,

I think I would limit it at 2 barrel 3 shot groups. Maybe 3 of each. At 100, 150, 200, and 50 yards. Maybe a couple of shots using the 200 yard and 300 yard leaves as at a test. That's 28 shots. Using up bullets and bruised shoulder.

Would be much easier for a medium bore.

If scoped, try some 2 Barrel groups scoped and unscoped.

Try shooting the left barrel first as well. Any great variation?

Using a different target for each R and L, but superimposing each new target, allows a progression of shots to be analysed. A computer graphic could be created. More simply copy the impacts onto clear sheets of plastic. Labelling each. Identifying each barrel.

One could examine a single group shot from each barrel, left's and rights. The first, second, third shots together. Or one could examine the first two shots of each groups of shots. Creating an average composite grouping of first shots from each barrel. Or one could compare the progression over different ranges. If the impacts are crossing, this should become evident.

If doing all this, you're probably better familiarised with your dr than 98% of owners.

One thing I like theoretically is for one barrel of a double rifle to be well sighted in. The other barrel nearby hopefully close enough. Instead of the compromise sighting. Theoretically if say the left barrel was sighted in like a single shot, longer shots could be possible.

Express sights are good for short range. Less for longer. A scoped double will be far more accurately shot at longer ranges.


Quote:

The doubles that I have shot seem to do well for 4 shots (2 per barrel) and then accuracy falls off somewhat until the barrels cool down.



The heat expansion on each barrel is probably having an effect.


--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

Edited by NitroX (10/05/23 07:31 PM)

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NitroXAdministrator
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Re: Double Rifles and Regulation [Re: NitroX]
      #376623 - 10/05/23 07:15 PM


Quote:

The only comment I would make is to add the word "hundred" as follows: I regulated my 9.3x74R 286 gr load to b about 30 mm apart at one "HUNDRED" metres. With the scope attached.



I think regulation would be excellent at one metre!

Yes I corrected that elsewhere already. Thanks.

I use an android tablet and smart phone. Very irritating auto self incorrect and small keyboards, make me look a moron as well ... Still laptopless ...

Quote:

This probably doesn't belong here but the front trigger on my Sempert & Krieghoff O/U fires the lower barrel. I always thought the front trigger fired the upper barrel. I found out mine shot that way when first shooting it. I only loaded the top barrel and no bng. Several trys without suggess, I loaded the bottom barrel and pulled the rear trigger and bang. Opening the gun, I found the top barrel had fired. Closing and pulling the front trigger, the rear barrel fired.

Is it set up that way because the lower barrel is more in line with the shoulder and therefore has less rise that it may be more accurate? Any thoughts?



Most 2x trigger under and overs shoot the lower barrel first. Theoretically the recoil is slightly less. The first barrel shot the most. Possibly other reasons for this sequence?

On my Tikka/Valmet, it was originally a selective single trigger. I had it converted to two triggers. The TOP barrel is fired by the first trigger. For an U/O shotgun this is unusual. And for a double rifle set of barrels. But for combinations with a shotgun as the top barrel, one wants the front trigger to fire the shotgun barrel.

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

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NitroXAdministrator
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Re: Double Rifles and Regulation [Re: kuduae]
      #376624 - 10/05/23 07:36 PM

Kuduae, thanks for those insightful comments.

I don't like the top shotgun barrel to be the rear trigger however. I prefer my Tikka's setup.
Bruno's/CZ's often had the top barrel being the rifle for combinations.

85lc, 23 years of NitroExpress.com and some practical experience must have rubbed off. Some might read my ravings and shake their heads.




--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

Edited by NitroX (07/06/23 03:02 AM)

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85lc
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Re: Double Rifles and Regulation [Re: NitroX]
      #376637 - 11/05/23 03:00 AM

Axel and John,

Thank you for the insight. Your explanation makes great sense.

My Sempert & Krieghoff is my first O/U that I have had. I resisited getting an O/U because I felt that double rifles and double barrel shotguns should be the more traditional SxS. However, after getting the Sempert & Krieghoff, I enjoy the O/U configuration. I may even go overboard and get an O/U shotgun.

--------------------
RB

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Nojden
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Re: Double Rifles and Regulation [Re: 85lc]
      #377190 - 06/06/23 11:17 PM

Good summary of the theories behind regulation of DR's

I have only experience of 3 different O/U rifles and so far my best results have been with open sights. This makes sense as all of them have been regulated with open sights on 60-100 meters.

Put a scope or a red dot on a double rifle and the regulation will probably change to a worse grouping, due to heating of the soldered barrels. With open sights, the front sight will "follow" the barrel movement (which varies a lot on different rifles) and keep the regulation better compared to a scope. The reticle on a scope, or a red dot, won't compensate for barrel heating and thus give a wider group after a few shots.

However- most scoped DR's with soldered barrels are possible to regulate very good with the first 2 rounds, but thereafter it might vary a lot.

My personal goal with my two existing DR's is to have a grouping of 1" at 50 meters and about 2" at 100 meters. I have managed that with the open sights, but not with my scoped rifle - the groups tend to be about the double in size.

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JudoFire
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Re: Double Rifles and Regulation [Re: Nojden]
      #377317 - 16/06/23 04:38 AM

Newbie here, fixing to build and regulate my own DR soon.
I thought it was a good read and pretty much on par with the research I have done thus far on the project.
Having zero experience with regulating and only knowing what I have read. Im not going to pull my hair out looking for perfection.
I wont tell you that Im going to try for a common POI or that I will end end up with right barrel right, left barrel left. For one thing, I dont think I can shoot well enough for it to make a difference and for another thing, I cant hold myself to trying to regulate with that kind of precision. I mean we're talking the difference of 3/4" or so (or about 2cm for you metric guys. LOL) between shooting POI or parallel.
That small difference isnt going to make any difference to me at 80 to 100 yards. Human error is worth at least that much and Im not building it to shoot prairie dogs.
My goal is to regulate to shoot a group I can live with. If I can hit a 110mm clay skeet target at 100 yards (92 meters) with both barrels, I couldnt give a rip less which barrel hit where. Thats a group I can live with and I would be happy with it. Thats about 4 MOA and plenty tight enough to ethically harvest anything Ill be shooting at.
95% of the time the rifle will be used to hunt deer in southern Michigan and in my 27 years of deer hunting, I have only ever shot one over 50 yards. It may find its way on my next mountain lion hunt although I am bowhunter and the last two times Ive gone mountain lion hunting, I have used my bow. Those dont offer long shots either. Dogs chase the cat up a tree, you shoot the cat out of the tree. 4 MOA accuracy at maybe 50 or 60 feet. At that range is a group of less than 17mm.
Not arguing with your post at all, I just think its WAY overthinking it. Which, If a guy was to spend five digits on a rifle that is being built by people that do this for a living, he shouldnt expect any less, but for the shadetree redneck like myself, if I can regulate it well enough to make it deadly on big animals inside of 100 yards. Thats good enough for me. I mean, I will make every attempt I can to get it as close as possible, but Im not going to spend weeks at the range and hundreds of rounds of ammunition to get it perfect. I dont think I could get it perfect. I cant shoot well enough to get it perfect. I would be wasting ammo just chasing around my own human error.
...and Im not a BAD shot but I am realistic....and realistically speaking, with iron sights at 100 yards, Im not expecting to touch holes. If I can get both barrels to impact on the same horizontal plane and shoot within an inch to an inch and a half of a vertical line, Im going to call it "regulated". I wont even care which side of the line they impact...I mean within reason. Obviously if theyre crossing early and hitting three inches apart at 100 yards, there is a little more work that could be done but you smell what Im stepping in.
It wouldnt matter to me if the bullet impacted an inch left of the line, and inch right of the line, or right ON the line. That is good enough accuracy to kill anything Ill be shooting at. If youre trying to get it any better than that, I think youre trying to pick fly poop out of chili.

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NitroXAdministrator
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Re: Double Rifles and Regulation [Re: JudoFire]
      #377325 - 16/06/23 06:55 PM

My post is about the theory of regulation and the practice of the theory. And an attempt to correct and educate some misconceptions of double rifle practice. Also to correct any errors of thinking I might have if any one says I am wrong.

Actual practice and individual experience may well differ. For example how a rifle shoots over different distances. Human error, rifle accuracy might make it different. The expectation of constant parallel shooting is very theoretical. In reality if a double rifle can shoot it's barrels and the expected number of shots into a useful combined group at an expected range one is doing well. For big bore DRs 100 hundreds is a long way, 150 yards longer than usual.

It would be interesting what ranges DR shooters actually use their rifles at. A thread will be started.

Same as I will try again to see if anyone can tell me, or actually test it out with their rifles, how well regulation works with a scope if regulated for a scope. Then remove the scope and shoot with open sights. Note and photograph the differences. As many DRs as possible.

Quote:

.
I wont tell you that Im going to try for a common POI or that I will end end up with right barrel right, left barrel left. For one thing, I dont think I can shoot well enough for it to make a difference and for another thing, I cant hold myself to trying to regulate with that kind of precision. I mean we're talking the difference of 3/4" or so (or about 2cm for you metric guys. LOL) between shooting POI or parallel.
That small difference isnt going to make any difference to me at 80 to 100 yards. Human error is worth at least that much and Im not building it to shoot prairie dogs.



I think a lot of people have trouble today using open sights well. As a kid I used a single shot .22 RF with open sights and could shoot it very well. Scopes ruin that ability. Unless one practices with them.

However you might find a scope on a double rifle improves your shooting with one immensely. I use my 9.3x74R to brain shoot buffalo. I certainly demand my 9.3 shoots better than you want.

Also stalking game in open country often needs a higher standard than shooting sitting from a highseat.

Quote:

I couldnt give a rip less which barrel hit where.



I'm glad real double rifle makers and regulators think differently.

Quote:

Not arguing with your post at all, I just think its WAY overthinking it.



Usually when people say that, they immediately do the opposite ... It's an educative article, not a bubba backyard gunsmithing manual.

Quote:

My goal is to regulate to shoot a group I can live with. If I can hit a 110mm clay skeet target at 100 yards (92 meters) with both barrels,



That might be a good test. Can one hit a clay target at one hundred yards, 70 yards, 50 yards, 150 yards. From field positions. Which with big bore would be off hand, or using shooting sticks. Maybe sitting.

Thanks for the interest. I hope your first attempt to regulate your rifle goes well.


PS you're welcome to eat fly shit ???? I'll cover my food and eat it hygienic ...

--------------------
John aka NitroX

...
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"I love the smell of cordite in the morning."
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JudoFire
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Re: Double Rifles and Regulation [Re: NitroX]
      #377327 - 16/06/23 08:48 PM

Quote:

It's an educative article, not a bubba backyard gunsmithing manual.



Yessir, totally understand. Im not arguing with the article at all, just sharing my personal stance on the subject. I am the bubba backyard gunsmith. LOL....so Im not even going to ATTEMPT to regulate with the kind of precision that fine rifle makers do.
I could regulate it for a year and it still wouldnt be perfect so Im going to be perfectly happy with getting it close enough to ethically harvest a big game animal within a reasonable distance and call it a day.....or a week....or however long it takes me to get it that close.

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NitroXAdministrator
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Re: Double Rifles and Regulation [Re: NitroX]
      #377333 - 16/06/23 11:28 PM

Geoffrey Couderc Regulating Photos





A temporary wedge in between the muzzles.



The double rifle in a frame for shooting regulation loads before fixing and soldering the barrels.


I've never seen a frame like this before?

--------------------
John aka NitroX

...
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"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

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Re: Double Rifles and Regulation [Re: NitroX]
      #377418 - 20/06/23 04:17 PM

No one commenting on Geoffrey's contraption?

The use of this, is not what I would expect during regulation?

--------------------
John aka NitroX

...
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93x64mm
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Re: Double Rifles and Regulation [Re: NitroX]
      #377428 - 20/06/23 09:32 PM

If it works then who's to worry about it being a contraption!
All the best with your work JudoFire!

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eagle27
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Re: Double Rifles and Regulation [Re: 93x64mm]
      #377438 - 21/06/23 10:22 AM

So what about the recoil factor that is supposedly so important and has to be taken into account in the regulation of double rifles? The rigid contraption seems to take all that out of the equation!

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Re: Double Rifles and Regulation [Re: eagle27]
      #377446 - 21/06/23 06:37 PM

Quote:

So what about the recoil factor that is supposedly so important and has to be taken into account in the regulation of double rifles? The rigid contraption seems to take all that out of the equation!



Yes, it would seem to be the case. I suppose the test is how does it shoot afterwards?

--------------------
John aka NitroX

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Re: Double Rifles and Regulation [Re: NitroX]
      #377447 - 21/06/23 06:43 PM

Another rule to maybe test out, is not to rest the forend on sticks or other rests directly. To put ones hand in between.

I noticed on a Cal Pappas hunting video in Alaska,he resting his .450/400 directly on shooting sticks. I asked him and he claimed it wasn't an issue.

Another shooting challenge "assumption" to test out I think.

I think a lot of these "assumptions" and "rules" are variable and not consistent across all firearms. Test samples might prove rules, or not, or variability.

--------------------
John aka NitroX

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Pugwash
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Re: Double Rifles and Regulation [Re: NitroX]
      #377453 - 21/06/23 10:44 PM

Geoffrey's contraption would only be used to adjust the barrels when heated. It wouldn't be on the barrels when the rifles shot.

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NitroXAdministrator
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Re: Double Rifles and Regulation [Re: Pugwash]
      #377455 - 22/06/23 12:00 AM

Quote:

Geoffrey's contraption would only be used to adjust the barrels when heated. It wouldn't be on the barrels when the rifles shot.



Thanks for the clarification.

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John aka NitroX

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Govt get out of our lives NOW!
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transvaal
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Re: Double Rifles and Regulation [Re: NitroX]
      #377457 - 22/06/23 01:13 AM

I will comment on the barrel clamp "contraption" by first stating that it is typical of the style and build of such devices.

Secondly, and more important I call your attention to the fact that attached to the top of the adjusting wedge is a block of steel to represent the weight and size of the final front sight ramp that will be attached to the barrels. This is very important as the weight and size of such a ramp affects the regulation of the barrels greatly and if one were to regulate the barrels without the ramp attached the regulation once the ramp was soldered in place afterwards the shot placement could be anywhere.

Lastly, I will state that I do not believe all gunmakers use such a barrel clamp device, but they are useful for regulation. The only difference in building such a device from my point of view is that I use screws that have very fine thread pitch as the coarse thread pitch on the screws as pictures can be difficult to adjust to only a few thousands of an inch movement of the barrels---screws with thread pitch something like 32 threads per inch is more appropriate.



Kindest Regards;
Stephen Howell

Edited by transvaal (22/06/23 11:06 AM)

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Re: Double Rifles and Regulation [Re: transvaal]
      #377475 - 22/06/23 07:01 PM

Never mind. If you do it that way and it works, it's a valid comment and an addition to 9ur knowledge and thread. Both how you do it, and how your contact or ex-contact at H&H does it. Is definitely an addition to this thread. Thank you for your contribution.

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

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coll416
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Re: Double Rifles and Regulation [Re: NitroX]
      #379017 - 01/09/23 09:11 AM

Thanks for the informtive article NitroX. I borrowed the much touted book by Graeme Wright which is well summarised by you, I took detailed notes which align with your advice.

I am at an early stage getting in sync with my Merkel 140 9.3x74. The rifle was regulated with 247gn Cone Point which are unavailable as are most non monolithic bullets near this weight, however Woodleigh might save me soon with some 250gn, I am presently guarding a small quantity of these. As a 9.3x62 fan I know what the 9.3x74 cartridge will do.

My focus is to practically duplicate the regulation ammunition for most of my shooting (pigs)whilst also achieving a workable 286gn load for heavier game. I think this means I have to get the 286gn load as close a possible velocity wise to the 247gn cone point factory spec of 2450fps. Current testing using AR2209 with the 270gn Speer seems to be confirming this assumption. I believe my chronograph will be critical as I get closer.

Present data collected:

Factory 286gn approx 2250fps LB 2.75" left & RB 2.5" right at 50m
Handload 270gn Speer approx 2350fps LB 1.5" left & RB 1.75" right at 50m this load shot much better than a 270gn load at approx 2260fps.

The elevation seeems to be working in reverse to single barrel rifles as the velocity increases the load shoots lower. The elevation is not a concern for me presently as it not moving greatly & I have adjustment on my front sight.

Thanks again for the advice.

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Re: Double Rifles and Regulation [Re: coll416]
      #379022 - 01/09/23 04:50 PM

Quote:

Thanks for the informtive article NitroX. I borrowed the much touted book by Graeme Wright which is well summarised by you, I took detailed notes which align with your advice.



I sold over 140 of his books. Still have a small handful of copies. Only person in the world probably with some still unsold. Must sell them immediately for some decent $$$!

One day I might have to actually read one!

I used a chapter of two. Never read it completely.

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

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