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Rechambering a combination firearm
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I am looking at a bruno in 12ga over 7x57R and was thinking that if I could rechamber into 7x65R then it would be worth purchasing and changing ot it to what I want. Is it possible and if so would does it cost, I look forward to all reply's Thanks Jim..
 
Posts: 11 | Location: Vancouver Island B.C. Canada | Registered: 02 January 2009Reply With Quote
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My first Q would be why,

If I would hawe other rifles in the same cal well then that might have been a reason good enough.

Second the answer depends,

on the gun, the barrels dimensions, and last and important for a lot of places can it be reproofed?

In all even if it could be done it´s rather costly and I would not spend that amount of money on a BRNO.

Best regards Chris
 
Posts: 978 | Registered: 13 February 2006Reply With Quote
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I would not do it.

But I think the 7x57R is plenty good enough for any game I would hunt with a combo gun out to 300 yards, assuming the gun was scoped.


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Posts: 16134 | Location: Texas | Registered: 06 April 2002Reply With Quote
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I know ballistically on paper the 7 x 65R looks like a lot more gun but I have used the 7 x 57R with 156 grain Norma Oryx loads and I don't think there is any game up to and including Elk where the 7 x 65R would give a meaningful advantage. I have dropped hogs in their tracks (live weight 220-240 lbs) at 150 meters that took no more than 5-10 strides and crumpled in a heap. That goes for the 6.5 x 55 too.
 
Posts: 1312 | Location: MN and ND | Registered: 11 June 2008Reply With Quote
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you can buy a reamer from the guy who lists them in the classified ads for about 50 bucks. run it in until the breech just closes on a shell then stop

the shell headspaces on the rim so it is easy to do. you'll like the 7 x 65 r - it is a real killer.
 
Posts: 174 | Registered: 12 September 2006Reply With Quote
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There seem to be some dimension problems with the conversion 7x57R to 7x65R.
See here:
http://www.triebel-guntools.de...20Patronenlagers.pdf

Fuhrmann
 
Posts: 110 | Location: Switzerland, Zug area (but German by birth...) | Registered: 19 December 2003Reply With Quote
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Jim,

The info from Triebel noted by fuhrmann is, of course; in German.

It is however solid advice and the diagram provided clearly depicts the two points where this conversion is not advised due to differences in the case dimensions; the 7x57R rim is thicker than the rim of the 7x64R, the second at the neck.

In Ken Water's Pet Loads there is an article of a similar rechambering where Ken did not heed the advice given by his gunsmith about setting back a barrel to be re-chambered from 7x57 to 7x64 Brenneke. Without barrel set-back the re-chambering resulted in a ridge on the neck which the diagram from Triebel clearly depicts.

Good Luck with your search for a 7x65R; although I shoot 2 7x57R's; a single shot & a Combo Rifle. Both have brought some large animals to bag. I agree with NE450 & JonP's advice above; IMO the 7x57R isn't about case capacity it's about using the right bullet (try Hornady 175 gr. RN or a RWS 177 gr. TIG) and putting it in the right spot - it'll do pretty much any reasonable job request quite handily.

As an example; while I'm gutting large Red Deer & Wild Boar that have recently expired from either of my 7x57R's; I tend to receive much unsolicited advice concerning how a larger/better/newer cartridge would have somehow improved the result. Wha-a-a-t; more dead? - Ugh, O.K.?

bewildered


Cheers,

Number 10
 
Posts: 3433 | Location: Frankfurt, Germany | Registered: 23 December 2004Reply With Quote
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Also, Gruetzi, Fuhrmann...hab in Risch fuer ein Jahr gewohnt...herrlicher Gegend!!!
 
Posts: 1312 | Location: MN and ND | Registered: 11 June 2008Reply With Quote
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I have reconsidered any will be leaving it alone sounds like it is not worth the cost and headache. Thanks for the replys
 
Posts: 11 | Location: Vancouver Island B.C. Canada | Registered: 02 January 2009Reply With Quote
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Lee LeBas rechambered a fine Triebel 16/8X57JR-360 to standard 8X57JR for me, and it worked out perfectly. It was far less of a problem than the 7X57 to 7X65 job, however.

You're wise to leave it 7X57, IMO. Wink
 
Posts: 1765 | Location: Northern Nevada | Registered: 27 February 2004Reply With Quote
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The mechanics of rechambering combo guns/drillings/break open guns, is pretty simple and can be done by hand easily. I've done dozens of them. As for this conversion, as some have pointed out, it's not recommended (for those reasons). The head diameter is also larger on the 7X57.
I would also echo the "wny?" I have passed on some 7X65 drillings in favor of 7X57's. I think it's a better caliber. More balanced case to bore capacity, very efficient, very accurate and sufficient for most of the game you will hunt. The brass, dies etc are also easy to come by.
Karamojo Bell felt it was adequate for elephant and killed a large number with it Wink.

I just bought a Krieghoff in 16 over 7X57. Look forward to hunting with it next season.




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Posts: 808 | Location: N. FL | Registered: 21 September 2003Reply With Quote
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quote:
Originally posted by luv2safari:
Lee LeBas rechambered a fine Triebel 16/8X57JR-360 to standard 8X57JR for me, and it worked out perfectly. It was far less of a problem than the 7X57 to 7X65 job, however.

You're wise to leave it 7X57, IMO. Wink


I'm curious as to why you re-chambered this gun. Was it just the availability of brass, dies etc.? You can load the 8X57R(360) up to about as hot as you'd want to load a JR in the same drilling action. Just curious. I have a hammer drilling in 8X57R that is great fun to shoot.




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Posts: 808 | Location: N. FL | Registered: 21 September 2003Reply With Quote
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I had four other guns in 8X57JR and didn't want to have to fool around with re-forming brass, then have a bastard round in the mix. It was easy as pie to do and shoots great. He had the reamers and did it as a favor.

I see no advantage to owning an 8X57JR-360 when it can be a standard 8X57JR. Wink
 
Posts: 1765 | Location: Northern Nevada | Registered: 27 February 2004Reply With Quote
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quote:
Originally posted by luv2safari:
I had four other guns in 8X57JR and didn't want to have to fool around with re-forming brass, then have a bastard round in the mix. It was easy as pie to do and shoots great. He had the reamers and did it as a favor.

I see no advantage to owning an 8X57JR-360 when it can be a standard 8X57JR. Wink


That's about as good a reason as I've seen Smiler But you can load a 8X57R to about anywhere you can a JR in these old guns if you only have one, it's probably best to just keep it the original caliber. I've had a number of people want me to do that over the years. Most I talked out of it Wink. The 8X57R (360) is actually a very efficient caliber & brass is very easy to make or buy for it.
But then, I also like the old 8X58R Sauer. Must be the traditionalist in me.




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Posts: 808 | Location: N. FL | Registered: 21 September 2003Reply With Quote
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quote:
Originally posted by brayhaven:

But then, I also like the old 8X58R Sauer. Must be the traditionalist in me.


You ARE strange! Eeker


Wink Big Grin
 
Posts: 1765 | Location: Northern Nevada | Registered: 27 February 2004Reply With Quote
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quote:
Originally posted by luv2safari:
quote:
Originally posted by brayhaven:

But then, I also like the old 8X58R Sauer. Must be the traditionalist in me.



Wink Big Grin

You ARE strange! Eeker

My wife says the same thing Roll Eyes The 8X58 reminds me of the venerable old 32/40.. another favorite of mine. But, when I'm not hunting with a drilling, it's usually a flintlock or a bow. I like to hunt close, so flat trajectory rifle calibers & scopes aren't a big interest of mine. I went through all that in my youth Wink
But, as a gunsmith, I have to do that stuff too..
"ain't nobody ever made a thin dime givin' folks what they need... You gotta give em what they want." Angel, from The Rockford Files




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Posts: 808 | Location: N. FL | Registered: 21 September 2003Reply With Quote
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We seldom get shots under 100 yards, and 200-300 are common. Calculating where the "botton of the rainbow" will hit can be a problem at times. Something reasonably flat shooting is best. I sight most rifles at 200 yards, except for the 9,3X72R.

Flintlocks?? Can you still see out of both eyes? hilbily
 
Posts: 1765 | Location: Northern Nevada | Registered: 27 February 2004Reply With Quote
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quote:
Originally posted by luv2safari:
We seldom get shots under 100 yards, and 200-300 are common. Calculating where the "botton of the rainbow" will hit can be a problem at times. Something reasonably flat shooting is best. I sight most rifles at 200 yards, except for the 9,3X72R.

Flintlocks?? Can you still see out of both eyes? hilbily

Ha, yes, but I'd never shoot one without shooting glasses Red Face). The eyes are fine (for an old codger) but the right eyebrow is, of course, gone Wink. I compete in 2 matches a month with them along with practice.
I've hunted out west, & know what you mean about the ranges. It can also be hard to judge distance (making a slow caliber harder to use). I decided to shoot an antelope with the flinter one year. I crawled up on a bunch that had a nice buck & estimated the range @ 150 yards which I'd shot at some for the trip. The ball landed between me & the lope & rolled to a stop @ 10 yards from him... Confused
I still like to get close, and killed a lot of western game (CO WY, ID)with bow & muzzle loader. Here in N. FL, I can take long shots if I want to, but most of my deer are shot at 20-50 yards. As I said, I like to be close to them.




"You can lead a horticulture, ... but you can't make 'er think" Florida Gardener
 
Posts: 808 | Location: N. FL | Registered: 21 September 2003Reply With Quote
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Sometimes you can get away with these rechamberings. A good friend of mine lost his thumb after rechambering a 7x57 to a .280 rem.


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Posts: 1562 | Location: Alaska | Registered: 05 February 2006Reply With Quote
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quote:
Originally posted by Akshooter:
Sometimes you can get away with these rechamberings. A good friend of mine lost his thumb after rechambering a 7x57 to a .280 rem.


Do you have any more info? Type gun, loads? reason damage occurred? Who did the re-chamber? I've never heard of a problem with one done correctly on a gun that could handle the pressures of the new round.
Just curiouos, but I'd think there is more to this story than just a re-chamber...




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Posts: 808 | Location: N. FL | Registered: 21 September 2003Reply With Quote
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this was about 20 years ago and was due to some poor choices by the gunsmith who barreled the rifle. it was a custom gun that was built in stages by several gunmakers.
What I know is that the guy who did the barrel used a thin tappered berrel chambered for 7x57 and ran a .280 reamer into it without measuring to be sure there was enough metal to support the longer chamber. The rifle was built on a 98 mauser action and the barreled action was sent to R.S.A. for a stock job. My friend took delivery of the complete rifle on arrival in Joburg and took it straight to the feild with him. On the first day of his hunt he took a hippo and while waiting for the thing to float to the surface he decided to try out his new rifle and sight it in. On the first shot the rifle expolded into several pieces shatering the stock the front thee quarters of the barrel blew forward and the action sustained an amazing amount of damage in the form of bending and twisting. I saw the rifle many years after the accedent and I'm still amazed that it did'nt kill him.
Bottom line not enough metal in the chamber area.
There is not any inherant problem with rechambering a rifle it just boils down to one thing and that is there has to be enough metal to support the new caliber.
One thing a person needs to be aware of is screw holes. most rifles dont have them in the chamber area but some do such as a Ruger #1. Deep screw holes will weaken the chamber and close measuring needs to be done when rechambering anything with screw holes in close proxemady to the chamber.


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Posts: 1562 | Location: Alaska | Registered: 05 February 2006Reply With Quote
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WAIT A SECOND......WAIT A SECOND.....
If you REEEEEEELY want a combo in 7x65R ...I have one available. It is absurdly accurate...a 1-holer at 100 meters. It has a 12 ga barrel....and it also has an extra 2-barrel 12 ga. set. It has a mounted scope (forget what kind...believe it's a German scope....high quality on claw mounts (on the combo barrel set). The gun is an Antonio Zoli.....and is a DAMN WONDERFUL GUN!!! I have a bunch of factory ammo ....and a bunch of 7mm bullets (I think German high-quality bullets ...RWS/DWM...unsure). The receiver is modestly engraved (as I recall) finish is at least 98% overall (maybe 100%....gotta look).
This is a FINE firearm....totally reliable....has a set trigger for use with combo set rifle barrel. Anyhow......the reason I am going to offer it for sale comes from a discussion in AR a few days ago...about where does one "send" his firearms when one gets older. My only son died. I have no-one to give them to....and there are many....another one I will sell is a pre-war Winch. Mod 70 with a mounted Nilon scope....that puts ALL 180 gr. bullets into a single hole when backed by 46 gr. of 3031. I haven't used it in years.....absolutely have loved it....if anyone wants to start a conversation with me about these....holler back
Alex
 
Posts: 2097 | Location: Gainesville, FL | Registered: 13 October 2004Reply With Quote
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quote:
Originally posted by Akshooter:
this was about 20 years ago and was due to some poor choices by the gunsmith who barreled the rifle. it was a custom gun that was built in stages by several gunmakers.
What I know is that the guy who did the barrel used a thin tappered berrel chambered for 7x57 and ran a .280 reamer into it without measuring to be sure there was enough metal to support the longer chamber. The rifle was built on a 98 mauser action and the barreled action was sent to R.S.A. for a stock job. My friend took delivery of the complete rifle on arrival in Joburg and took it straight to the feild with him. On the first day of his hunt he took a hippo and while waiting for the thing to float to the surface he decided to try out his new rifle and sight it in. On the first shot the rifle expolded into several pieces shatering the stock the front thee quarters of the barrel blew forward and the action sustained an amazing amount of damage in the form of bending and twisting. I saw the rifle many years after the accedent and I'm still amazed that it did'nt kill him.
Bottom line not enough metal in the chamber area.
There is not any inherant problem with rechambering a rifle it just boils down to one thing and that is there has to be enough metal to support the new caliber.
One thing a person needs to be aware of is screw holes. most rifles dont have them in the chamber area but some do such as a Ruger #1. Deep screw holes will weaken the chamber and close measuring needs to be done when rechambering anything with screw holes in close proxemady to the chamber.


There is actually a very large margin of safety in barrel thickness. I recall reading in Gen Julian Hatcher's book where he deliberately tried to blow up a springfield barrel by turning it down to 1/8" over the chamber. He fired it with regular ressure & 75,000 psi proof loads with no change in dimensions. He then turned the barrel to 1/16" wall thickness over the chamber and fired it some more. No changes with std loads. When he fired it with a 75,000 PSI proof load it finally let go and blew a piece out the side.
Of course you'd never make a barrel that thin, but it illustrates the safety margin. A metal flaw, dusty bore, moisture in the bore, or any other obstruction, improper handloads etc, can all lead to failures. In 40+ yrs working on guns, I've never seen a screw hole cause a barrel wall to rupture & I've seen them very close over the chamber and all the way through into the barrel ,a little ahead of the chamber.
Just my experience YMMV.




"You can lead a horticulture, ... but you can't make 'er think" Florida Gardener
 
Posts: 808 | Location: N. FL | Registered: 21 September 2003Reply With Quote
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I agree it really dos'nt take much metal to handle the pressures of most modern cartridges. A good example of this is on my F.A. .454 casull. the chamber walls are very thin yet still the .454 is hardly a low pressure round.

the thing that guys like Dick Casull learned in developing revolvers for high pressure cartridges was to use a 5 shot cylinder so the notch for bolt would not be cut over the top of the chamber but rather btween the chambers on the cylinder. a deep screw hole will weaken the chamber in the same way.

If you want to see a gun blow the chamber right off the top of the barrel there was and epasode of what ever that T.V. show is where the guys in their white lab coats try to wreak guns. I dont remember wich show that is but its somthing like shooting U.S.A. I'm sure most of you have seen the one I'm talking about. Anyway they blew up a TC encore with a super hot load. The experiment blew the chamber wall right off the top but the action was still intact. (not serviceable but not blown apart ether)

The TC is one of the few guns that have screw holes over the chamber area. Did the screw holes contribte to the failure of the chamber I don't know.

P.O. Ackley did experiments where he blew guns up much the same as Hatcher. In all of ackleys experiments the recivers gave way long before the barrels wich validates the statement that there is a large margin of safty. at some point the chamber becomes to thin and I agree it is a rare barrel that dosen't have plenty of meat to handle more that it's share of pressure but sometimes rare situations come up (as with revolver chambers etc). One thing I would keep in mind here would be that some of the thinest barrels I've ever seen are the ones on combo guns.


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Posts: 1562 | Location: Alaska | Registered: 05 February 2006Reply With Quote
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quote:
Originally posted by Akshooter:
One thing I would keep in mind here would be that some of the thinest barrels I've ever seen are the ones on combo guns.


True, especially drillings, but the pressure falls off very quickly as the bullet leaves the case, and most are pretty beefy in the chamber area and for the first couple inches.
I'd have to look at how that T/C came apart to see if the screw holes were a factor. No doubt, any structural integrity gap will weaken the barrel. But, with normal or even somewhat above normal pressures, screw holes are not a threat. Warren Center did a lot of testing on that with super hot loads when he was developing the contender. He found something like a 3X safety factor, even in the very hot calibers.




"You can lead a horticulture, ... but you can't make 'er think" Florida Gardener
 
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