What is the purpose of an inner "C" stop ring?
- Thread starter Clark
- Start date
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Dennis Sorensen
Guest
It can be used to 'capture' a threaded piece... so it does not get lost when unscrewed...
What are you talking about?
What are you talking about?
The barrel has male threads and screws into the receiver's female
threads.
The shoulder of the barrel stops at and presses against the end of the
large ring of rifle receiver.
Some rifles have an inner "C" stop ring that is where the breech of
the barrel presses against.
The Russians made an inner stop ring on the 91/30 from 1891 to 1942, but omitted it from 1942 to 1959 when production ceased.
The 98 Mauser has in inner C ring.
A rem 700 does not have an inner C ring.
Newer rifles do not have this feature.
I is very hard to machine this feature into a receiver.
Butch Lambert
Active member
Could it be to help with escaping gases in case of a case failure.
Butch
Butch
L
luke wads
Guest
its for head spacing !!!
the inner ring on 98 Mauser was to allow the head space to be set from it ,so at field level barrels could be replaced with out any gauges , when rebarelling m98's the shoulder of the barrel should not lock up one the od of the action but on this ring, ok for millatary use as they only care if it work not how good it is for accuracy ect
the inner ring on 98 Mauser was to allow the head space to be set from it ,so at field level barrels could be replaced with out any gauges , when rebarelling m98's the shoulder of the barrel should not lock up one the od of the action but on this ring, ok for millatary use as they only care if it work not how good it is for accuracy ect
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Butch Lambert
Active member
I make my Mauser's tenon .001 long inorder that it will seat on the front ring just after touching the C ring. Most of the many Mauser gunsmiths that I know do not let the tenon touch the C ring and tighten them to the shoulder on the front ring of the receiver.
Butch
Butch
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Dennis Sorensen
Guest
I have never heard it referred to as an inner 'c' ring before..
On a Mauser 98 that is referred to as the headspace ring (at least that is what I was taught) and the barrel is supposed to set hard against it, not on the receiver face.
I usually machine the barrel shoulder about 2 thou longer than the ring measurement to assure the butt contacts solidly first, then the shoulder.
Many military barrels have no shoulder to contact with...
On a Mauser 98 that is referred to as the headspace ring (at least that is what I was taught) and the barrel is supposed to set hard against it, not on the receiver face.
I usually machine the barrel shoulder about 2 thou longer than the ring measurement to assure the butt contacts solidly first, then the shoulder.
Many military barrels have no shoulder to contact with...
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Butch Lambert
Active member
Some have the C ring and some have a H ring. If you will do a good search you will find the C ring is to keep gas from escaping down the LH raceway. It is not for setting headspace.
Butch
Butch
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Dennis Sorensen
Guest
I agree with this guy...
http://www.mausercentral.com/barrelfitting.htm
I think Mr. Mauser designed the ring to set the barrel against... that was the way all the barrels were fitted... and it set the headspace measurement quite closely among actions... close enough to be safe. I can't remember a factory M98 barrel not fitted that way and I can not remember any of them with a shoulder diameter large enough to use against the face of the action.
Everything I have read about venting gas has no mention of the "C" ring used for that purpose... the most common improved gas handling abilities are described below...
The M-98 incorporated gas-venting holes in the bolt body that direct gas downward into the magazine and a gas deflecting flange on the bolt sleeve to protect the user from a pierced primer sending back gas along the locking lug raceways. It is said that Paul Mauser’s losing his sight in one eye was the impetus for all the designed-in gas safety features.
If a pierced primer can send gas back along the raceways, a ruptured case certainly can do the same with or without a "C" ring. That's my thoughts anyway...
.
http://www.mausercentral.com/barrelfitting.htm
I think Mr. Mauser designed the ring to set the barrel against... that was the way all the barrels were fitted... and it set the headspace measurement quite closely among actions... close enough to be safe. I can't remember a factory M98 barrel not fitted that way and I can not remember any of them with a shoulder diameter large enough to use against the face of the action.
Everything I have read about venting gas has no mention of the "C" ring used for that purpose... the most common improved gas handling abilities are described below...
The M-98 incorporated gas-venting holes in the bolt body that direct gas downward into the magazine and a gas deflecting flange on the bolt sleeve to protect the user from a pierced primer sending back gas along the locking lug raceways. It is said that Paul Mauser’s losing his sight in one eye was the impetus for all the designed-in gas safety features.
If a pierced primer can send gas back along the raceways, a ruptured case certainly can do the same with or without a "C" ring. That's my thoughts anyway...
.
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I read the above and tried again to figure it out.
I was wondering how the gas could be it, as I have had (3) Mauser extractors blow out in the last year. The C ring just concentrates pressure on the extractors.
The sights are soldered on. They can't change that.
I can't be for headspace, because that must precede clocking the sights.
Then it came to me.
The barrel shoulder and large ring are so stiff, when they touch, the headspace does not change with more torque. All the twisting just increases the thread crush.
They want to set the headspace, and clock the sights on a jig.
They want inner C ring compliance + thread crush compliance so the barrels are on tight when the sights are straight up.
THAT is why they made an inner C ring, it is for interchangeable barrels with sights that clock.
I wondered how they got those barrels to clock, but I never counted ALL the variables before.
Thanks guys.
I was wondering how the gas could be it, as I have had (3) Mauser extractors blow out in the last year. The C ring just concentrates pressure on the extractors.
The sights are soldered on. They can't change that.
I can't be for headspace, because that must precede clocking the sights.
Then it came to me.
The barrel shoulder and large ring are so stiff, when they touch, the headspace does not change with more torque. All the twisting just increases the thread crush.
They want to set the headspace, and clock the sights on a jig.
They want inner C ring compliance + thread crush compliance so the barrels are on tight when the sights are straight up.
THAT is why they made an inner C ring, it is for interchangeable barrels with sights that clock.
I wondered how they got those barrels to clock, but I never counted ALL the variables before.
Thanks guys.
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Dennis Sorensen
Guest
M98 barrels will often switch from action to action with the headspace within tolerances but it would be a rare instance when sights would index... I don't think I have ever seen an instance when the sights indexed correctly on an M98 barrel swap.
They did not make the "C" ring so sights would 'clock'...
They did not make the "C" ring so sights would 'clock'...
This is the way I was taught in gunsmithing school by Franz Achleithner a Ferlach trained armourer. But I've never heard the inner shoulder referred to as a C ring.
al
Butch Lambert
Active member
Lets try this:
According to de Haas in "Bolt Action Rifles", the ring serves these functions:
1. Gas seal around bolt head
2. Strengthens receiver ring
3. Helps funnel rounds into the chamber
4. Primary torque shoulder
He is about as good an authority as I know.
Butch
According to de Haas in "Bolt Action Rifles", the ring serves these functions:
1. Gas seal around bolt head
2. Strengthens receiver ring
3. Helps funnel rounds into the chamber
4. Primary torque shoulder
He is about as good an authority as I know.
Butch
jackie schmidt
New member
Butch
In the old "Gun Kinks" publications of the '60's, they advised truing the front of the reciever if you planned on seating the barrel against it. That seems logical, as I doubt most were as true as that inner seating surface.
If I remember, they stated that the proper barrel seating surface was indeed the inner landing ring.
I did a few Mausers way back then, I would always seat the barrel against the inner surface, leaving just .001 or so between the barrel and the front of the reciever strictly for cosmetic purposes, so there would not be a noticeable gap..........jackie
In the old "Gun Kinks" publications of the '60's, they advised truing the front of the reciever if you planned on seating the barrel against it. That seems logical, as I doubt most were as true as that inner seating surface.
If I remember, they stated that the proper barrel seating surface was indeed the inner landing ring.
I did a few Mausers way back then, I would always seat the barrel against the inner surface, leaving just .001 or so between the barrel and the front of the reciever strictly for cosmetic purposes, so there would not be a noticeable gap..........jackie
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Dennis Sorensen
Guest
I don't argue that he is a good authority on a lot of things... but he gives 4 reasons what he thinks the 'ring' functions are... his opinion...
1. Gas seal around bolt head... If the "C" ring was not there the barrel would be machined back farther and the "C" shape could be machined into the barrel with the same effect. One can say the rear of the barrel is a gas seal. The flaw in the thought that it is a gas seal is that gas expands in all directions and the cut in the 'C' for the extractor lets gas do just that in a case failure. The "C' does not seal the chamber nor the bolt head. The big improvement in gas handling are the holes in the bottom of the bolt body venting gas into the mag well and the large flanged bolt shroud.
2. Strengthens receiver ring... more material there does strengthen the action. It adds resistance to the action threads expanding.
3. Helps funnel rounds into the chamber...the feed ramp behind the bottom locking lug recess and the feed rails do that. If they haven't got the bullet pointing into the chamber the "C" ring will simply block the feeding.
4. Primary torque shoulder. Yes - it is the primary torque shoulder.
More of my thoughts...
I have tried to compile matrix of bolt action features, and it looks like a synopsis of that book.
What a book!
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Dennis Sorensen
Guest
I don't argue that he is a good authority on a lot of things... but he gives 4 reasons what he thinks the 'ring' functions are... his opinion...
1. Gas seal around bolt head... If the "C" ring was not there the barrel would be machined back farther and the "C" shape could be machined into the barrel with the same effect. One can say the rear of the barrel is a gas seal. The flaw in the thought that it is a gas seal is that gas expands in all directions and the cut in the 'C' for the extractor lets gas do just that in a case failure. The "C' does not seal the chamber nor the bolt head. The big improvement in gas handling are the holes in the bottom of the bolt body venting gas into the mag well and the large flanged bolt shroud.
2. Strengthens receiver ring... more material there does strengthen the action. It adds resistance to the action threads expanding.
3. Helps funnel rounds into the chamber...the feed ramp behind the bottom locking lug recess and the feed rails do that. If they haven't got the bullet pointing into the chamber the "C" ring will simply block the feeding. This controlled round feeding is a big point of the M98 but the "C" ring isn't responsible for that.
4. Primary torque shoulder. Yes - it is the primary torque shoulder.
More of my thoughts...
L
Larry Elliott
Guest
Maybe I'm just dumber than average, but it seems that if a primer blows or the case head blows, the gases aren't going to be contained by a ring that's larger than the bolt face. Unless there's a problem that blows the chamber and receiver ring at which point it'd also seem to be of no use.
The hole through this ring has to be larger than the OD of the chamber or rounds won't feed so it can't really contain escaping gas backwards from the chamber.
The hole through this ring has to be larger than the OD of the chamber or rounds won't feed so it can't really contain escaping gas backwards from the chamber.
Butch Lambert
Active member
I'm going to pour a little fuel on the fire. I asked this question on AR.COM on the gunsmithing forum. These guys are mauser custom gunsmithing guys and not BR guys. You can form your own opinion, but I think they agree on the help in gas retainment.
http://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/6531089131
Butch
http://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/6531089131
Butch
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Dennis Sorensen
Guest
An interesting read...
It seems no one over there mentioned or acknowledged the fact that all the military M98's set the barrels hard against the 'C' ring... that the measurement from the 'C' ring to the bolt face is a very consistent figure, allowing quite precise head spacing of mass produced/chambered barrels as the military did.
One fellow mentions Bill Prator, quoted below in italics:
FWIW, our machine-shop instructor at Trinidad was a fellow called Bill Prator, one of P.O. Ackley's barrelmakers before he began teaching. Boots Obermeyer, in his interview article for Precision Shooting magazine, has called Bill Prator "a giant in the barrelmaking field" and that freely-expressed opinion by such a univerally-acclaimed practitioner(Boots) should establish Prator's barreling credentials to EVERYONE'S satisfaction!
Prator taught us to face off the front of the ring (using a THREAD mandrel) and to use the freshly-trued front face as the contact face, and to cut the rear face of the barrel so as to contact but not crush against the internal ring.(!) A secondary step is to remove the first thread behind the front face, especially on the small rings.
A moment's reflection will show almost anyone that there are several ways to accomplish the same thing as long as the machinist is competent, thoughtful and open-minded.
Mr Prator was my instructor for 2 years (1966-67). I spent a lot of time with him at the gunsmithing school and in his barrel making shop at home. He was a great teacher.
I remember clearly that he recommended you make a mandrel and face the front of the receiver ring on a M98 if you were going to shoulder the barrel on it... I also remember that if you did not do that, you were to fit your barrel to contact the inner ring firmly before any light contact with the face of the action.
I believe it was at that time I first heard of that inner ring referred to as the headspace ring... I never gave it much thought as to what it was called. I always from day one when re-barrelling butted barrels tight against it and lightly on the shoulder. Of course all the military barrels refitted were against the inner ring because of the lack of shoulder diameter.
No doubt these differences of opinion will continue forever... too bad Paul didn't write it all out...
It seems no one over there mentioned or acknowledged the fact that all the military M98's set the barrels hard against the 'C' ring... that the measurement from the 'C' ring to the bolt face is a very consistent figure, allowing quite precise head spacing of mass produced/chambered barrels as the military did.
One fellow mentions Bill Prator, quoted below in italics:
FWIW, our machine-shop instructor at Trinidad was a fellow called Bill Prator, one of P.O. Ackley's barrelmakers before he began teaching. Boots Obermeyer, in his interview article for Precision Shooting magazine, has called Bill Prator "a giant in the barrelmaking field" and that freely-expressed opinion by such a univerally-acclaimed practitioner(Boots) should establish Prator's barreling credentials to EVERYONE'S satisfaction!
Prator taught us to face off the front of the ring (using a THREAD mandrel) and to use the freshly-trued front face as the contact face, and to cut the rear face of the barrel so as to contact but not crush against the internal ring.(!) A secondary step is to remove the first thread behind the front face, especially on the small rings.
A moment's reflection will show almost anyone that there are several ways to accomplish the same thing as long as the machinist is competent, thoughtful and open-minded.
Mr Prator was my instructor for 2 years (1966-67). I spent a lot of time with him at the gunsmithing school and in his barrel making shop at home. He was a great teacher.
I remember clearly that he recommended you make a mandrel and face the front of the receiver ring on a M98 if you were going to shoulder the barrel on it... I also remember that if you did not do that, you were to fit your barrel to contact the inner ring firmly before any light contact with the face of the action.
I believe it was at that time I first heard of that inner ring referred to as the headspace ring... I never gave it much thought as to what it was called. I always from day one when re-barrelling butted barrels tight against it and lightly on the shoulder. Of course all the military barrels refitted were against the inner ring because of the lack of shoulder diameter.
No doubt these differences of opinion will continue forever... too bad Paul didn't write it all out...