"Three Rings of Steel" Question/Discussion
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Jay Idaho
Guest
I've removed three Rem barrels to allow the bolt to open after firing with grossly over-pressure loads. I do believe that the bolt snout expands to form a pretty good seal, not perfect but pretty good. The chamber expanded a few thou ahead of the belt on a 300 Win Mag.
The custom actions that have sliding extractors and a ring around MOST of the case rim can present other problems. If the barrel chamfer is closely matched to the chamfer (cone) on the front of the bolt and clearance is held to a few thou, you have a pretty good seal. I've seen one that suffered a case rupture and the minimum clearance contained the pressure too well. A section of the ring surrounding the case rim came out the left port and left a nice, long (22 stitches) slice in the shooters right cheek.
I think that it is wise to have at least .010 clearance and 5 degrees difference between bolt chamfer (cone) and barrel chamfer.
The custom actions that have sliding extractors and a ring around MOST of the case rim can present other problems. If the barrel chamfer is closely matched to the chamfer (cone) on the front of the bolt and clearance is held to a few thou, you have a pretty good seal. I've seen one that suffered a case rupture and the minimum clearance contained the pressure too well. A section of the ring surrounding the case rim came out the left port and left a nice, long (22 stitches) slice in the shooters right cheek.
I think that it is wise to have at least .010 clearance and 5 degrees difference between bolt chamfer (cone) and barrel chamfer.
C
Con Cross
Guest
Gentleman, can you believe that when the case head goes, it's always a bad news and the Remington bolt nose configuration can be the good news of the bad news.
Con
Con
Butch
Agreed...especially after seeing numerous examples of Remington's machine work. I should have been a bit more specific in my post. We were talking about re-barreling 700's from an accuracy standpoint. Prior to this conversation, I always thought that clearance between bolt nose OD and counterbore ID was, for lack of a better term, not critical. Not that I was ever sloppy, or excessive with my clearances...I cut the counterbore .010 over bolt nose OD on my first Remington. What I didn't want was the bolt nose OD touching the counterbore ID, because I have read where that is an accuracy no-no. But then I've read post's written here, by some very knowledgeable folks, who don't worry about the bolt touching the barrel. I dunno...
Justin
Agreed...especially after seeing numerous examples of Remington's machine work. I should have been a bit more specific in my post. We were talking about re-barreling 700's from an accuracy standpoint. Prior to this conversation, I always thought that clearance between bolt nose OD and counterbore ID was, for lack of a better term, not critical. Not that I was ever sloppy, or excessive with my clearances...I cut the counterbore .010 over bolt nose OD on my first Remington. What I didn't want was the bolt nose OD touching the counterbore ID, because I have read where that is an accuracy no-no. But then I've read post's written here, by some very knowledgeable folks, who don't worry about the bolt touching the barrel. I dunno...
Justin
jackie schmidt
New member
Nothing is Completely Safe
Granted, when a Rifle is so grossly overloaded as to excede the strength of the case, nothing is going to hold 100 percent of the shrapnel and gas in. But I feel safe in saying that the Remington "three rings of steel" comes about as close as any design ever concieved.
Many would ask, "why doesn't everyone use this design". The single biggest reason is it is very difficult to build a controle feed Rifle with the big claw extractor. The Remington design mandated a push feed set-up. That so called "weak extractor" that Remington uses allows them to encapsolate the entire assy inside the bolt face reccess..........jackie
Granted, when a Rifle is so grossly overloaded as to excede the strength of the case, nothing is going to hold 100 percent of the shrapnel and gas in. But I feel safe in saying that the Remington "three rings of steel" comes about as close as any design ever concieved.
Many would ask, "why doesn't everyone use this design". The single biggest reason is it is very difficult to build a controle feed Rifle with the big claw extractor. The Remington design mandated a push feed set-up. That so called "weak extractor" that Remington uses allows them to encapsolate the entire assy inside the bolt face reccess..........jackie
The post you are referring to was concerning the gas coming out of the vent in the bolt body [ pierced primer scenerio ]. The gas coming out of this vent is directed at the side of the receiver, not the raceway. Eventually the gas will make it's way down the raceway but some of it will have escaped through the hole in the receiver. Any reduction in pressure and volume would be beneficial to the face behind the rec.
On a case head failure the locking lug area of the rec is basically divided into two chambers since the locking lugs are vertical. These two chambers also include the bolt raceways. Makes a body appreciate the bolt baffle setup that Savage uses. Savage vents both sides of the front rec ring.
C
Con Cross
Guest
Mr. Crb, would you believe, that most of the observants would believe that with the Remington bolt nose deep in the recess the gas turns 90 degree corner around the entire bolt face of the nose and then it's projected straight back along the nose of the bolt?
Mr. Crb, can you believe that your described explanation would have slightly better merits with a flat face bolt?
Gentleman, would you agree, that even the non believer can believe that any reduction of gas coming back is better than nothing and that's very beneficial.
Con
Remington extractor
With the above in mind, doesn't the modification of adding a Sako type extractor weaken the Remington design? Why do people modify the Remington in this way and what are the benefits?
Chino69
With the above in mind, doesn't the modification of adding a Sako type extractor weaken the Remington design? Why do people modify the Remington in this way and what are the benefits?
Chino69
Dave Tooley
Active member
Justin
As with anything in life it's about compromises.
I learned a long time ago that if you fit the bolt nose too close to the barrel there was a good possibility that that rifle was going to be finicky to tune up.
The reason being the bolt nose was touching the barrel from time to time. It will drive you crazy until you figure that out. In a Remington you have an extractor that slices over the case rim pushing the bolt to one side and the ejector pushing on the back of the case to hold it in that position. It's probably touching more often than we think.
I use .010" end clearence and .015" total radial clearence now. That supports rule #1 in my shop. "Don't do anything to make the phone ring" If pressures are high enough to rupture a case, the added clearence will mean nothing when the dust settles. The case head will expand and the bolt nose will obturate to slow the gas down. There really is no seal as some think. It's all about deflection, you are not going to force all the gas down the barrel. Ever seen a 308 case fired in a 7MM Mag. It's easy to see the thin side of the brass. The gas will come out one side. It's not a total melt down. Although 46 grs. of 4227 instead of 46 grs. of 4064 does a pretty good job of things. That will melt brass, cut steel and blow investment cast receiver rings into 3 pieces.
As far as shearing the lugs off the bolt. I've never heard of that happening. Brass yields at a far lower pressure than steel. The case is a safety valve. It yields first. I believe Mike Walker when he developed the 700 series even welded the barrel shut on some and couldn't blow the bolt out.
Chino69
I install Sako extractors for several reasons.
1. the customer wants it. This gets back to the myth about a Remington extractor being weak.
2. To change the diameter of the bolt face to fit a different case.
All this gets back to you shouldn't be looking into a loading port. Bad JuJu
Here's a trick everyone can use when you have pressures high enough to lock a bolt down. It will save you a lot of grief.
equipment needed
1. two blocks of wood
2. 3lb hammer
3. a friend
put a block of wood on the ground. As solid as you have available.
put the muzzle on the block of wood, have a friend hold the rifle verticaly
take the other block of wood and place on the bolt shroud
pick up the 3 lb. hammer and knock the crap out of that block of wood about 3 times.
Check to see if the bolt handle will move now, if it doesn't repeat the hammer drill
If it does bring the bolt handle up until it contacts the camming surface on the action.
put the rifle back on the bench and insert blunt cleaning rod down the barrel into the case
have your friend tap the cleaning rod with the 3 lb hammer while your lifting up and out on the bolt handle. This should get the bolt out without doing anymore damage.
Do not use the hammer on the bolt handle. If you do and it comes off don't call me.
Dave
As with anything in life it's about compromises.
I learned a long time ago that if you fit the bolt nose too close to the barrel there was a good possibility that that rifle was going to be finicky to tune up.
The reason being the bolt nose was touching the barrel from time to time. It will drive you crazy until you figure that out. In a Remington you have an extractor that slices over the case rim pushing the bolt to one side and the ejector pushing on the back of the case to hold it in that position. It's probably touching more often than we think.
I use .010" end clearence and .015" total radial clearence now. That supports rule #1 in my shop. "Don't do anything to make the phone ring" If pressures are high enough to rupture a case, the added clearence will mean nothing when the dust settles. The case head will expand and the bolt nose will obturate to slow the gas down. There really is no seal as some think. It's all about deflection, you are not going to force all the gas down the barrel. Ever seen a 308 case fired in a 7MM Mag. It's easy to see the thin side of the brass. The gas will come out one side. It's not a total melt down. Although 46 grs. of 4227 instead of 46 grs. of 4064 does a pretty good job of things. That will melt brass, cut steel and blow investment cast receiver rings into 3 pieces.
As far as shearing the lugs off the bolt. I've never heard of that happening. Brass yields at a far lower pressure than steel. The case is a safety valve. It yields first. I believe Mike Walker when he developed the 700 series even welded the barrel shut on some and couldn't blow the bolt out.
Chino69
I install Sako extractors for several reasons.
1. the customer wants it. This gets back to the myth about a Remington extractor being weak.
2. To change the diameter of the bolt face to fit a different case.
All this gets back to you shouldn't be looking into a loading port. Bad JuJu
Here's a trick everyone can use when you have pressures high enough to lock a bolt down. It will save you a lot of grief.
equipment needed
1. two blocks of wood
2. 3lb hammer
3. a friend
put a block of wood on the ground. As solid as you have available.
put the muzzle on the block of wood, have a friend hold the rifle verticaly
take the other block of wood and place on the bolt shroud
pick up the 3 lb. hammer and knock the crap out of that block of wood about 3 times.
Check to see if the bolt handle will move now, if it doesn't repeat the hammer drill
If it does bring the bolt handle up until it contacts the camming surface on the action.
put the rifle back on the bench and insert blunt cleaning rod down the barrel into the case
have your friend tap the cleaning rod with the 3 lb hammer while your lifting up and out on the bolt handle. This should get the bolt out without doing anymore damage.
Do not use the hammer on the bolt handle. If you do and it comes off don't call me.
Dave
I recently picked up a 700 with a PTG bolt with the Sako extractor. There IS a lot of metal removed from the root area of the locking lug. It's probably even more pronounced on this bolt because it's for a 223.
D
Dennis Sorensen
Guest
It weakens the design totally. This becomes a problem only when there is a catastrophic case failure.
With a Sako extractor conversion the case will blow as this picture shows... and the extractor and all the debris exit never to be found again. (Hopefully not in ones head) This shows how poor the support is with the conversion. This picture was sent to me. The owner is now in the process of replacing all of his converted bolts back to original configuration. This happened to him (right handed shooter) but he was just lucky at the time his left hand friend was not shooting it. I believe there has been one death associated with a left hand shooter and a right hand conversion. It was reported on this forum a couple of years ago.
This next picture is of a case failure in a bolt with the 700 extractor. The case head has expanded and is "welded" to the bolt. I cut off the protruding case to show this better. Part of the reason this failed where it did is because the bolt nose was damaged (allowing the brass to flow out that way) from removing a previous case that was welded in the bolt face from excessive pressure. You can see on the nose a smaller damaged area and where the case blew out there was a larger damaged area. With this failure only gases escaped, no flying metal pieces. If the bolt nose had not been previously damaged I don't think the case wold have ruptured at all.
Originally I think the conversion was done to accommodate the PPC case... and I think that some people think the conversion is a stronger extractor. There is no truth to that. After the conversion it is is an easier extractor to replace at home... the original 700 extractor is very strong. It easily will hold over 200 pounds in a straight pull. I don't know how hard you would have to pull to break the bolt handle off. The conversion will never be a problem if you never have a bad case failure... but it definitely weakens the original design.
This next picture shows a sectioned .223 case and just how heavy the brass is. Keep in mind a case like this hangs out of the barrel on an unaltered 700 about .160". I think on a Sako conversion it is altered so it only hangs out about .125".
C
Con Cross
Guest
Mr. Dennis Sorensen, even with pictures like this how long do you think it will take for the next gentleman to come along and say; I had all my Remingtons Sako modified and I can't see anything wrong with it to weaken the bolt or the design.
Gentleman, can you believe that there're plenty of you who believe that the Sako bolt conversion is superior?
Con
Gentleman, can you believe that there're plenty of you who believe that the Sako bolt conversion is superior?
Con
jackie schmidt
New member
Here is The Deal
When you add a Sako Extractor to a Remington 700 style bolt, you TOTALLY negate the safety enginering placed into the design by Remington.
I have told this story on this Forum before, but we have new visitors, so here it is again.
About 6 or so years ago at the old Lake Houston Gun Club, a shooter, (left handed), was practicing with a custon Rem 700 in 243 Ackley. It was a right hand action with a Sako Extractor added.
He had been shooting 68 grn match bullets with a BIG dose of 4350, just seeing what kind of velocity he could get. It was avery hot day. He decided to switch to some 90+ grn bullets, (I do not know which brand). The thing he FORGOT to do was drop the charge. The resulting catastrophie welded what was left of the case head inside the bolt reccess, and the Sako extractor ended up in his head. This is like getting shot with a small 22 short.
To get the bolt open, they had to remove the barrel.
This is a circumstance of a lot of bad things comming together. The shooter was left handed, shooting a right handed Rifle. He pulled a really stupid move in forgetting to drop the powder charge.
Does this mean Sako coversions in Remingtons are unsafe. Well, if you blow a case, that extractor, (and other things), are going out that raceway. Whether it hits anything, and hurts someone, is blind luck.
The simple fact is, there are literally THOUSANDS of these conversions out there. Several companies sell the kit to perform the task.
But, just because we do it, does not change the fact that we are taking perhaps the safest Rifle design yet, (in terms of confining hot gas and shrapnel in the event of a castostrophic failure). and by our own "ingenuity", negate the entire concept. ..........jackie
When you add a Sako Extractor to a Remington 700 style bolt, you TOTALLY negate the safety enginering placed into the design by Remington.
I have told this story on this Forum before, but we have new visitors, so here it is again.
About 6 or so years ago at the old Lake Houston Gun Club, a shooter, (left handed), was practicing with a custon Rem 700 in 243 Ackley. It was a right hand action with a Sako Extractor added.
He had been shooting 68 grn match bullets with a BIG dose of 4350, just seeing what kind of velocity he could get. It was avery hot day. He decided to switch to some 90+ grn bullets, (I do not know which brand). The thing he FORGOT to do was drop the charge. The resulting catastrophie welded what was left of the case head inside the bolt reccess, and the Sako extractor ended up in his head. This is like getting shot with a small 22 short.
To get the bolt open, they had to remove the barrel.
This is a circumstance of a lot of bad things comming together. The shooter was left handed, shooting a right handed Rifle. He pulled a really stupid move in forgetting to drop the powder charge.
Does this mean Sako coversions in Remingtons are unsafe. Well, if you blow a case, that extractor, (and other things), are going out that raceway. Whether it hits anything, and hurts someone, is blind luck.
The simple fact is, there are literally THOUSANDS of these conversions out there. Several companies sell the kit to perform the task.
But, just because we do it, does not change the fact that we are taking perhaps the safest Rifle design yet, (in terms of confining hot gas and shrapnel in the event of a castostrophic failure). and by our own "ingenuity", negate the entire concept. ..........jackie
Mike Bryant
Active member
I have a friend who was shooting a pre-64 Winchester 70 in a factory barreled .220 Swift. He blew a case in it and wound up with the claw extractor being blown out the loading port of the action. He never did find the extractor. As near as I could tell the cause of the blown case was a combination of .006" too much headspace in the rifle combined with setting the shoulder back .006" too much for a combined total of .012" too much headspace. Too much headspace combined with a hot load of H335 caused the problem. It wasn't the type of extractor that was the problem just poor reloading technique with little knowledge of controlling headspace in loaded rounds. The barrel was about shot out anyway. I replaced the extractor and other parts, rebarreled it for him and built him a chamber gage showing him how to set up his dies properly for his chamber. That ended the problem. It would just about be heresy to claim that the pre-64 Win 70 is an unsafe action. I don't think it is, but bad loading techniques can cause problems with it or just about any other action.
I'd strongly suggest if you are going to use a Sako style extractor to have the bolt and barrel set up with .125" counterbore to get as much of the case up in the chamber as possible. There are lots of custom benchrest actions that are currently using Sako style extractors with .125" or less recess from the end of the bolt to the bolt face. I've never heard of a custom action losing a sako style extractor because of a PPC case blowing a primer. I don't know that I've ever heard of Lapua PPC case blowing a primer. I did see the results of a Sako .220 Russian balloon head case that blew a primer in an action with a sliding plate extactor. It blew the extractor so hard into the receiver threads that it left the impression of the threads on the end of the extractor. The extractor stayed in the bolt. This was a right handed shooter with a left port. The action was Lowell Frei's. Mistakes happen even with the best of us. Lowell forgot and loaded a Lapua case charge into a Sako .220 Russian. There was a reason why the old Sako case was shot at 27.5 gr or therabouts. There is no way it would handle the loads that Jackie and others are shooting in their PPC's with Lapua brass.
I'd strongly suggest if you are going to use a Sako style extractor to have the bolt and barrel set up with .125" counterbore to get as much of the case up in the chamber as possible. There are lots of custom benchrest actions that are currently using Sako style extractors with .125" or less recess from the end of the bolt to the bolt face. I've never heard of a custom action losing a sako style extractor because of a PPC case blowing a primer. I don't know that I've ever heard of Lapua PPC case blowing a primer. I did see the results of a Sako .220 Russian balloon head case that blew a primer in an action with a sliding plate extactor. It blew the extractor so hard into the receiver threads that it left the impression of the threads on the end of the extractor. The extractor stayed in the bolt. This was a right handed shooter with a left port. The action was Lowell Frei's. Mistakes happen even with the best of us. Lowell forgot and loaded a Lapua case charge into a Sako .220 Russian. There was a reason why the old Sako case was shot at 27.5 gr or therabouts. There is no way it would handle the loads that Jackie and others are shooting in their PPC's with Lapua brass.
Butch Lambert
Active member
I beg to differ with you Stephan, I believe more have sliding plates and remington extractors.
Butch
Butch
jackie schmidt
New member
Butch
The only action I have, (actually,my Son's), that has a Sako style extractor is the Bruno that I bought about 6 years ago. But, since it is a regular RB-LP, the extractor is covered when the bolt is in Battery.
I would think that a custom action that has the same configuration as a Remington, (RB-RP), and a Sako Extractor, would have the same propensity for calamity as a Remington, as the extractor would have a clear path out the back through the right raceway.
For those that do not know, Sako solves this problem with sheathing that covers the extractor as the bolt is turned into the battery position......jackie
The only action I have, (actually,my Son's), that has a Sako style extractor is the Bruno that I bought about 6 years ago. But, since it is a regular RB-LP, the extractor is covered when the bolt is in Battery.
I would think that a custom action that has the same configuration as a Remington, (RB-RP), and a Sako Extractor, would have the same propensity for calamity as a Remington, as the extractor would have a clear path out the back through the right raceway.
For those that do not know, Sako solves this problem with sheathing that covers the extractor as the bolt is turned into the battery position......jackie
MColeman
Club Coordinator
Correct. No action ever made by Ralph Stolle or George Kelbly in their line of actions has a Sako type extractor, for instance. They are all sliding plates.
J