lancaster
(.470 member)
09/03/20 06:53 AM
perforated double rifle barrels

friend send me an e-mail because he is looking for 6,45 mm berdan primer. comes out another friend have a .577 double he will use for safari with old kynoch ammo. primers misfire, commercial reloader stand ready to make the ammo working again but dont have primer - if I can help. yes
got pic of the double now









dont know more about the DR but who make such holes into the barrel?


tinker
(.416 member)
09/03/20 07:15 AM
Re: perforated double rifle barrels

Will it still shoot to regulation with the "compensator" vents?

Will we ever find out?

I'd guess that these holes didn't come from the maker.
Maybe the fellow who cut the rib for the optic mount knows who drilled the muzzles.


bwanabobftw
(.375 member)
09/03/20 07:21 AM
Re: perforated double rifle barrels

Criminal !!!!!!!!!!!!!!!!!
Robert


3DogMike
(.400 member)
09/03/20 07:23 AM
Re: perforated double rifle barrels

For the Kynoch .577 (& other large Kynoch Nitro Express cartridges) the proper Berdan primer is the RWS 6507.
Should be readily available in Europe.

Whomever ported that rifle should be horsewhipped and then tarred and feathered.
- Mike


85lc
(.375 member)
09/03/20 07:27 AM
Re: perforated double rifle barrels

And after tarred & feathered, drawn & quartered with their head put on a pole.

tinker
(.416 member)
09/03/20 07:28 AM
Re: perforated double rifle barrels

Quote:



Whomever ported that rifle should be horsewhipped and then tarred and feathered.
- Mike





Drawn
Quartered
...


Ash
(.400 member)
09/03/20 09:24 AM
Re: perforated double rifle barrels

What make is the double? Hopefully something new?

NitroXAdministrator
(.700 member)
09/03/20 02:05 PM
Re: perforated double rifle barrels

Looks older.

"Magnaported" defaced barrels. It would be nice to know if it still regulates at all?

Again rear sight grooved for a modern 'optical' sight. At least not so obtrusive.

Some owners should stick to plastic stocked bolt actions.


93x64mm
(.416 member)
09/03/20 04:49 PM
Re: perforated double rifle barrels

Quote:

Looks older.

"Magnaported" defaced barrels. It would be nice to know if it still regulates at all?

Again rear sight grooved for a modern 'optical' sight. At least not so obtrusive.

Some owners should stick to plastic stocked bolt actions.




I was thinking the same thing John, how would manga-porting affect the regulation of a double?
Most doubles regulate within 100 fps or so of there desired speed, I simply do not know much about muzzle brakes or porting of barrels - except they divert enough gas to make a fair difference in felt recoil!
But do they in the process drop that much velocity in the last 2 inches or so, if then perhaps like chopping of 2 inches of barrel - perhaps 50 fps maybe?
The question then begs, exactly whereabouts is the regulation of this rifle (hopefully on the faster side & slightly crossing - if I've got that part right) - otherwise if it is on the 'slower' part then it could literally deregulate itself by going too slow?

Still it is a shame to see a double 'defaced' like that - but hey it's the owner's rifle he can do as he/she pleases!
Certainly not my cup of tea to do so that's for sure.


NitroXAdministrator
(.700 member)
09/03/20 06:00 PM
Re: perforated double rifle barrels

In a big recoiling rifle, regulation will also be affected by the recoil movement of the muzzles. The projectile will have travelled some distance in the barrel with it moving under recoil, before exiting.

This is obvious will say a slow moving .45/70 single barrel. A slower load may shoot HIGHER than a faster recoiling load. Because the bullet is in the barrel longer and it has whipped up higher before exiting the muzzle.

A side by side will also have sideways movement.

So theoretically the muzzles will have moved up and to the right comparatively for a side by side right barrel. This is taken into account when positioning the two barrels during regulation.

Putting a scope on a rifle, ie weight. can affect regulation.

Putting a gas break or magnaporting to reduce recoil WILL affect regulation.

It would be good to know how it shoots since its defacement.


Marrakai
(.416 member)
09/03/20 10:24 PM
Re: perforated double rifle barrels

My suspicion is that barrel porting close to the muzzles reduces only that part of the recoil impulse generated by the rocket effect.
That occurs primarily AFTER the projectile exits the muzzles and might therefore have little effect on regulation.

Magna-porting on the other hand acts to counter muzzle rise by directing some of the rocket effect upwards, forcing the muzzles down just before the projectile exits the muzzle, and might therefore be expected to have some effect on regulation.

Of course this is pure speculation on my part, probably worth precisely what you payed for it!

Still a hell of a thing to do to a double rifle!


85lc
(.375 member)
10/03/20 04:10 AM
Re: perforated double rifle barrels

If a double is ported, the porting will not be around the perimeter of the barrel but just to one side, which should affect the regulation, causing the gun to cross-fire. I guess after porting, the barrels could then be regulated to mitigate the effects of porting.

Waidmannsheil
(.400 member)
10/03/20 07:02 AM
Re: perforated double rifle barrels

Not sure why anybody would buy a 577 and then try to make it shoot like something smaller. Part of the enjoyment of having a big bore rifle is all that goes with it. This includes the weight, size, sound and recoil. Some people obviously like saying they have a 577 but are terrified of shooting it.

Matt.


Ash
(.400 member)
10/03/20 01:57 PM
Re: perforated double rifle barrels

Quote:

Not sure why anybody would buy a 577 and then try to make it shoot like something smaller. Part of the enjoyment of having a big bore rifle is all that goes with it. This includes the weight, size, sound and recoil. Some people obviously like saying they have a 577 but are terrified of shooting it.

Matt.




My thoughts on everyone with muzzlebreaks and 8lb .500’s etc.


NitroXAdministrator
(.700 member)
11/03/20 12:10 AM
Re: perforated double rifle barrels

I don't like porting or muzzle breaks on any hunting rifle.

On a range, people can all wear ear protection. In the field not so.

My Tikka U/O 12 g does have porting.

Why buy some big recoiling rifle and then put some ugly muzzle break on it? Use a rifle you are capable of handling.


lancaster
(.470 member)
11/03/20 07:29 AM
Re: perforated double rifle barrels

talk with my friend on the phone, double is an army & navy 577 bought lately
holes looking very exact and like they were there for ever, who knows

he got 50 old kynoch cartridges, new brass or ammo is not to get now. horneber is a friend and visit him for a cup of tea quite recently. says he needs a big order to adjust the machinery for this caliber.
so the old brass will be loaded again with new powder and primer for a south african hunting trip in may thats in the stars now because of corona.


NitroXAdministrator
(.700 member)
11/03/20 07:58 AM
Re: perforated double rifle barrels

Good luck for your friend. In getting it loaded, getting the brass and the safari.

It is possible a gunmaker may have re-regulated the barrels the same time as drilling the holes in it. Hope for your friend that was the case. Or it has been sold and possibly re-sold because it no longer regulates.

Like these Pedersoli .45/70's that have been re-chambered and how often they are re-sold again and again and again. Any reason?

Hopefully that .577 was cheap. Hope it works out for your friemd.


snipped


ducmarc
(.400 member)
12/03/20 10:40 AM
Re: perforated double rifle barrels

termites... know the family well.looks like it needs shorter barrels. better yet i'll trade him my old f-150 and then he can save face.

carpediem4570
(.300 member)
01/09/20 01:14 PM
Re: perforated double rifle barrels

Is it my imagination or does it appear the muzzle brake was added to the barrels and the front sight moved forward?

If you look closely at the photo there is a very slight variation in colour where the muzzle brake meets the barrel. It appears there is a faint line between the two.

And if this sis the case, then one would assume that would really mess with regulation.

Kind regards,

Carpediem


3DogMike
(.400 member)
01/09/20 01:32 PM
Re: perforated double rifle barrels

Quote:

Is it my imagination or does it appear the muzzle brake was added to the barrels and the front sight moved forward?

If you look closely at the photo there is a very slight variation in colour where the muzzle brake meets the barrel. It appears there is a faint line between the two.

And if this sis the case, then one would assume that would really mess with regulation.

Kind regards,

Carpediem



+1 good eye ..... there is indeed something fishy going on at the end of the barrels.

another observation: this rifle has been restocked. No way the old Army & Navy had a close curl pistol grip on the stock and a disgusting beaver tail forend as well.
So with all the gunsmith added Botox and facelift maybe it was re-regulated for the mega blaster porting?

- Mike


carpediem4570
(.300 member)
01/09/20 02:30 PM
Re: perforated double rifle barrels

"So with all the gunsmith added Botox and facelift maybe..."

Bahahahahaha. Oh, that is funny.

Kind regards,

Carpediem


EDELWEISS
(.375 member)
01/09/20 10:19 PM
Re: perforated double rifle barrels

DON'T HATE ME but we love Howdahs and we admit many were cut down from rifles and shotguns, so a modified gun to make it better for the shooter seems like something we should embrace. I know a few of you have said that you have guns you know were shortened at some point. NO I dont like the looks of porting on a classic gun, I dont like plastic guns; but I dont like kale either.

That being said I there are otherways ways to reduce FELT recoil besides porting. Some are better than others. I bought a Ruger No1 that had been customized by J D Jones (of the Contender Hand Cannon fame). Mine was #5. It was 577 Nitro and had Magnaported trapezoid cuts and a spring style buttpad. I thought it was cool at first. Maybe I could have gotten past the Magnaporting BUT the spring butt pad was Too Much for me so I sold it, now I miss it???


What this guy has done is no different from guys who have sporterized military guns. I dont especially like it and I would have counseled him against it BUT it sounds like the current owner might have bought it that way. Do I wish it was done to a modern gun, instead of a Army/Navy; yes of course. Look at it this way, when he decides to sell it you can offer him less money....


tinker
(.416 member)
02/09/20 11:44 AM
Re: perforated double rifle barrels

It's good to distinguish between porting and braking.

Both require sufficient muzzle pressure in order to make any sort of difference.

Porting can affect muzzle rise or flip.
Porting does not require a great deal of wall thickness.

Braking affects the rearward movement of the rifle (the recoil impulse).
In order for braking to work, the system needs wall thickness - it needs *surface area*

Some rifle barrels have enough wall thickness to allow a braking effect by way of properly designed and applied porting. The radial brake is a very effective type of porting application that can give excellent braking effect.



These radial brakes need wall thickness in order to do their job.
The forward-moving exhaust gas and ejecta hit the walls of the porting and basically pull the rifle forward against the rearward force of recoil.

There are other types of braking, but the example of the radial brake most closely resembles the job done in the rifle shown earlier in this thread.


wjw
(.275 member)
02/09/20 02:06 PM
Re: perforated double rifle barrels

Appears that someone in the double rifle's past has had a Pendleton de-kicker muzzle break machined into the barrel. These were available in the 1960's and possibly earlier and are most often seen in photos of .460 Weatherby Magnums of that era.

Bill



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