Any thoughts/experience which would be the
stronger action for a build, a SA Stevens 200
or a Marlin XS7? How would either compare to
the strength of a Rem 700 action?

With it's 3 solid rings of steel surrounding the case head the 700 is one of the strongest designs going.

What Westpac said, and PLENTY of it.

Back in the '60s my friend and smithing mentor Jerry (W. Gerald) Dykes, P.E., was working for the local DoD skunkworks on a hypervelocity experiment that would later develop into the magnetic rail gun project among others. His task was to design, build and operate a device to fire super-velocity rifle cartridges to discover the limits of the rifled bore. He handloaded his own cartridges and ultimately had to fab a cannon-like action to handle the 150K psi.

On the way to that result, he destroyed about a dozen rifle actions over a period of several years including most of the commercial ones available back then. He didn't tell us a lot because of security considerations but over the years it developed that the Remington was the only action that he absolutely COULDN'T blow up. Winchester, Mauser, Weatherby all separated into several pieces but the Remington just swelled & brazed the bolt head and the barrel had to be unscrewed for bolt removal. Jerry said he eventually got tired of all the hassle and just fabbed his cannon action.

Pressure was over 150K psi and velocities were over 5000 fps. Jerry said that he eventually DID achieve 6000 fps but he had to evacuate the bore first, tests proved that the column of air in the bore wouldn't/couldn't move fast enough to allow velocities in the trans-6000fps range.

Too bad his data was restricted, it'd be interesting to compare notes with Ackley and Hatcher about the various actions at various pressures.

But anyway his experiences convinced ME!
Regards, Joe

Thanks, guys but I should have been more
explicit in my question.

I should have asked which receiver of the
Marlin and Stevens is the strongest, and left
out any mention of the 700 "action".

This project will not need the strength of the
three solid rings of steel surrounding the
case head, but the receiver itself will need
to be strong enough to keep from flexing at
all.

Oh, you mean the most rigid? They are both round receivers so I would look for the one with the most metal.

From my expirience, the ability to handle presure, comes down to the extractor.
Or with other words, casehead support.
Even old m96 mausers can handle 120.000+ psi, if you remove the extractor, flattens the boltfront, and ad a tight fitting steelring around the casehead, supporting the entire protrution.

Our blowup tests showed that actions with clawextractors blew around 75.000psi
actions with sakotype extractors blew around 120.000psi
actions with suficient casehead support like Remmington blew around 145.000psi

Those test were performed with cal 6.5x55.
All blowups started when the casehead let go, increasing the presurearea at the front of the bolt.

As long as you could containe the presure inside the case, most actions could stand the presure

The Savage action is very strong and safe. From examples I have seen of rifles fired with severe over loads, it is equal to the 700. One action was fired with a load with enough pressure to actually expand the receiver ring and require that the barrel be bored out of the receiver. The bolt stayed in place, the shooter was unhurt, and the rifle looked OK (it wasn't!)The Marlin's strength may be similar but I have not seen what happens to one of these when stressed.
By the way, all actions flex a certain amount. Regards, Bill.

It would really depend upon what your building. The Rem is likely the strongest but if your building less than an 06 something or other the Savage is plenty strong enough.

Flexing cannot be avoided, what is important is
that the flexing is uniform. The best information I have ever seen is in
"Rifle Accuracy Facts by Vaughn.
Good Luck!

quote:

Originally posted by hawkins:
Flexing cannot be avoided, what is important is
that the flexing is uniform. The best information I have ever seen is in
"Rifle Accuracy Facts by Vaughn.
Good Luck!

The key is symetri. Unsymetrik flexing is unpredictably and create barrelvibrations. Symetrical fleksing only stretches the action axial, and does hardly create barrelvibrations. Therfor symetri basically means predictability, and high tolerence for varyations in loads and oil in the chamber

I was with you up to the end. What has oil in the chamber to do with barrel flex. An oiled case comes back sooner, but with the same force
at peak pressure.
Good luck!

quote:

Originally posted by hawkins:
I was with you up to the end. What has oil in the chamber to do with barrel flex. An oiled case comes back sooner, but with the same force
at peak pressure.
Good luck!

A dry case sticks to the chamberwall, and can carry apx 50% of the load, leaving only 50% to the boltface.
Oil in the chamber prevents stick, therfor leaving 100% of the thrust to the boltface.
further you have all the in-betweens varying the boltthrust.

Varying boltthrust equals different flexing, and if asymetric, equals different vibrations pattern, and different poi.

quote:

Originally posted by jørgen:
From my expirience, the ability to handle presure, comes down to the extractor.
Or with other words, casehead support.
Even old m96 mausers can handle 120.000+ psi, if you remove the extractor, flattens the boltfront, and ad a tight fitting steelring around the casehead, supporting the entire protrution.

Our blowup tests showed that actions with clawextractors blew around 75.000psi
actions with sakotype extractors blew around 120.000psi
actions with suficient casehead support like Remmington blew around 145.000psi

Those test were performed with cal 6.5x55.
All blowups started when the casehead let go, increasing the presurearea at the front of the bolt.

As long as you could containe the presure inside the case, most actions could stand the presure

This is exactly how I've understood it. I cannot confirm the numbers as I have no pressure measuring equipment.....but can easily believe everything in jørgen's post.

2 of my 7 Stevens 200s have locked up ejectors from rather heavy loads that just were beggining to produce a slightly hard bolt handle lift. roger

In a dry chamber the primer pushes the case forward pressure holds it there until somthing like 40 KPSI. At that point the case hamber.
stretches back leaving the stress ring. With an oiled case it comes back at once with the same force as a dry chamber. The case fits the chamber and lacks a stress ring.
Non of this concerns the flexing moment caused
by the barrel being above the center of the stock.
Good luck!

quote:

Originally posted by DannoBoone:
This project will not need the strength of the
three solid rings of steel surrounding the
case head, but the receiver itself will need
to be strong enough to keep from flexing at
all.

If you want a stiff action without a very expensive custom, try the Savage target action. Closed bottom, closed top, small port. Much more rigid than those sporter actions mentioned.

http://www.savagearms.com/firearms/actions/target/

quote:

Originally posted by hawkins:
In a dry chamber the primer pushes the case forward pressure holds it there until somthing like 40 KPSI. At that point the case hamber.
stretches back leaving the stress ring. With an oiled case it comes back at once with the same force as a dry chamber. The case fits the chamber and lacks a stress ring.
Non of this concerns the flexing moment caused
by the barrel being above the center of the stock.
Good luck!

I guess that you asume that at 40KPSI the case lets go and stretches, creating the stressring.
I dont think you are right, as the brass starts yielding at that presure, and only presure above the mentioned 40kpsi puts presure on the bolt.
all metals with enough elongation will continue to carry the yieldstrength untill it ruptures. That brings us back to the issue, an oiled chamber prevents the case to carry its yieldstrength putting all the presure on the boltface.

Higher boltface thrust gives more actionflexing on an asymetrical action. More actionflexing create more barrel whiping. More and warying barrel whipping gives unpredictability.

This phenomen is well described from most actions with rearlocking, or asymetric locking. The norwegians who used the Kragh Jørgensen for competitions for decades werry well knew that they didnt stand a chance in competitions, if it was raining. Because when loading whet cartridges, they lost substantial accuracy.

I once tested an old Schultz & Larsen rearlocking rifle. It was a caliber 300win, it was tested with 108grains Remmington, 180 grains winchester and 180 grains hornady. All 3 types of ammo was in this rifle capable of ½" 3 rd grups. The poi was 8" horisontal different betven rem and win, the hornady was 8" low but centered betwen the rem and win.
Then we put a tiny drop of oil on a hornady case, before loadinf. this rd hit 10" below the rest of the Hornadys. then we fiered 2 more hornadys without adding more oil, and the last was back in the original groupe.

The same 3 types of ammo tested in 3 modern frontlocking S&L rifles resulted in 1 grup at less than 1.5" fiering 3 rd of each brand. Adding oil didnt change poi att all

I always reckon the 3 rings of steel on a Remington is advertising baloney, true the bolt surrounds the cartridge head but most of the support is air as the inside of the bolt is cut away for the extractor. Custom Remington type action made for a sako type extractor do surround the cartridge head with 3 rings of steel so better fit the description. Which is stronger, safer in the event of failure?

quote:

Originally posted by Lincs Stalker:
I always reckon the 3 rings of steel on a Remington is advertising baloney, true the bolt surrounds the cartridge head but most of the support is air as the inside of the bolt is cut away for the extractor. Custom Remington type action made for a sako type extractor do surround the cartridge head with 3 rings of steel so better fit the description. Which is stronger, safer in the event of failure?

The manufacturer does not claim that the three rings of steel was designed to support the case head, the three rings of steel "surround" the case head, and act to suppress/contain the explosive and castrophic effects of a case head separation. And this it does better than most! As anyone who has ever examined various actions suffering case head separations can attest to.

The addition of ANY external extractor to any Remington style bolt, and breech, provides an opening and potentially disastrous escape path for the gas, pieces of brass and chunks of the extractor during a case head separation making it much more dangerous under this condition than the stock bolt head. Of course the solution to reducing the likelihood of experiencing such a failure is to have ones head screwed on straight when handloading.

quote:

Originally posted by Lincs Stalker:
I always reckon the 3 rings of steel on a Remington is advertising baloney, true the bolt surrounds the cartridge head but most of the support is air as the inside of the bolt is cut away for the extractor. Custom Remington type action made for a sako type extractor do surround the cartridge head with 3 rings of steel so better fit the description. Which is stronger, safer in the event of failure?

You can bet your summersavings that the 3 rings of steel on a rem, is not baloney.
Yes the bolt has a cutout for the extractor, but this cutout is almost filled with the extractor, leaving little room for the brass to flow into.
At medium highpresure the brass will expand untill stopped by the bolt and extractor. at werry high presure the skirts of the bolt will expand untill stopped by the counterbore of the barrel. only at werry extreme presure the bolt will let go.
In case of adding a sakotype extractor, there will bee a gab from the original cutaway for extractor, + there will bee a posibility for the presure to flip out the bottom of the sakoextractor (completly bypassing the 3 rings of steel), combined with the fact that there is a nesesceary play around the top of the sakoextractor, allowing it to snap ower the case rim, when loading a cartridge.

This is written by a person that in manny other situations calls a remmington, for a "hardly ableson rifle"

One of our local bench rest shooters who liked to run things a bit hot out smarted the three rings of steel. He had a case failure and the gases burned a hole through the edge of the bolt head and vented out the ejection port. It was a stock unmodified Remington 700 bolt and barrel.

There was some testing done a few years back by one of the gunrags. The strongest action that they tested was the Japanese Ariska action. Of the modern, commercial actions, the Savage 110 tested as the strongest.

quote:

can carry apx 50% of the load, leaving only 50% to the boltface.

Not with modern high pressure loadings.
The math is very easy to do. Anyone that has handloaded for many .303 Lee-Enfields can confirm this.

quote:

Originally posted by Fjold:
There was some testing done a few years back by one of the gunrags ad the strongest action that they tested was the Japanese Ariska action. Of the modern, commercial actions, the Savage 110 tested as the strongest.

I've examined a couple of Savage 110 platforms that literally disintegrated due to case head separation. I have yet to see one Remington.

quote:

Originally posted by DannoBoone:
Any thoughts/experience which would be the
stronger action for a build, a SA Stevens 200
or a Marlin XS7? How would either compare to
the strength of a Rem 700 action?

IMO there is nothing like a Rem 700 when the issue is "holding in a mistake"

My Rem 700 in .22-250 once held in a load I made (still don't know what happened) that expanded the primer pocket .021"....I could read the letters "22-250" on the bolt face...I had to beat the action open with a 2X4!

It went right back to killing prairie dogs after I pryed the case from the bolt....(it was tack welded to the bolt face)....

Believe it or not, I had a similar experience with a push feed M-70 in .220 Swift. I had to remove the barrel to clear the problem. The rifle went right back to shooting after a new extractor was installed!

I have no personal experience with the Savage action or the Marlin.....But having looked at the Savage, I suspect it will be equal in strength to the two I just mentioned.

The critical issue is that it must stop the flow of brass in case of serious over pressure. It must prevent gas flow into the receiver ring. I doubt any action does this better than the Remington 700.....but at least the Win M-70 push feed does it just fine and I'd bet on the Savage action as well.....but then you still have a Savage in the end!!!

Oh.....absolutely no CRF action I've ever owned will do this!!!

There used to be an old "Rule of Thumb" among the cognoscente that if you wrapped a P-64 M70 or a Mouser with 6.5 layers of Duct Tape(or Duck Tape if you can get the Ducks to make it for you), that it will double the Action Strength. Biggest problem was getting that 0.5 layer Wrap.

As a nice side benefit, it made them fit better in the Termite Food stocks.

Hope that helped ya'll!

quote:

Originally posted by vapodog:

quote:

Originally posted by DannoBoone:
Any thoughts/experience which would be the
stronger action for a build, a SA Stevens 200
or a Marlin XS7? How would either compare to
the strength of a Rem 700 action?

IMO there is nothing like a Rem 700 when the issue is "holding in a mistake"

My Rem 700 in .22-250 once held in a load I made (still don't know what happened) that expanded the primer pocket .021"....I could read the letters "22-250" on the bolt face...I had to beat the action open with a 2X4!

It went right back to killing prairie dogs after I pryed the case from the bolt....(it was tack welded to the bolt face)....

Believe it or not, I had a similar experience with a push feed M-70 in .220 Swift. I had to remove the barrel to clear the problem. The rifle went right back to shooting after a new extractor was installed!

I have no personal experience with the Savage action or the Marlin.....But having looked at the Savage, I suspect it will be equal in strength to the two I just mentioned.

The critical issue is that it must stop the flow of brass in case of serious over pressure. It must prevent gas flow into the receiver ring. I doubt any action does this better than the Remington 700.....but at least the Win M-70 push feed does it just fine and I'd bet on the Savage action as well.....but then you still have a Savage in the end!!!

Oh.....absolutely no CRF action I've ever owned will do this!!!

I am curious as to how you actually KNOW this based on facts from experience? I am not trying to belittle your comments here, I am genuinely curious.

I once had a Dumoulin .243Win. blow and these were built on the FN "H-ring" actions, all that happened was a small amount of gas escaped and the ejector needed replacement, as well as the stock....even this would have been vented on a 98 by the thumb notch, IMO.

I share your enthusiasm for the PF Mod. 70s for certain applications and am trying to find a couple of the short ones for builds chambering .22-250 and so forth, but, I see no disadvantage to wellmade CRF rifles in big game hunting situations and several advantages...all relative to where and what you hunt, of course.

quote:

Originally posted by SR4759:

quote:

can carry apx 50% of the load, leaving only 50% to the boltface.

Not with modern high pressure loadings.
The math is very easy to do. Anyone that has handloaded for many .303 Lee-Enfields can confirm this.

her you have the math in metric

Standard caliber
case intermal diameter = 10mm = 0.75cm2
Wallthikness of the brass in the stressarea 1mm
Total amount of brass in the stressarea 11 x 3,14 x 1mm =34,5mm2
yieldstrength of the brass in the stressarea 34,5mm2 x 3okg/mm2 = 1036kg

internal thrust at 3000bar/43000psi 3000 x 0,75cm2 = 2250kg

thrust needed to overcome the yieldstrength 1036kg = 46%
rest to push on the boltface 2250 - 10360 = 1214kg = 54%

Those figures is apx, but pretty close to the real world so if APX = +-10% it is pretty close

quote:

Originally posted by jørgen:

quote:

Originally posted by SR4759:

quote:

can carry apx 50% of the load, leaving only 50% to the boltface.

Not with modern high pressure loadings.
The math is very easy to do. Anyone that has handloaded for many .303 Lee-Enfields can confirm this.

her you have the math in metric

Standard caliber
case intermal diameter = 10mm = 0.75cm2
Wallthikness of the brass in the stressarea 1mm
Total amount of brass in the stressarea 11 x 3,14 x 1mm =34,5mm2
yieldstrength of the brass in the stressarea 34,5mm2 x 3okg/mm2 = 1036kg

internal thrust at 3000bar/43000psi 3000 x 0,75cm2 = 2250kg

thrust needed to overcome the yieldstrength 1036kg = 46%
rest to push on the boltface 2250 - 10360 = 1214kg = 54%

Those figures is apx, but pretty close to the real world so if APX = +-10% it is pretty close

Wrong- The area where the brass actually stretches is .025 to .030 inch.

Check it out over at Varmint Al's FEA.

Std case OD = .469
std case ID = .409 at the point of stretching

Area of the wall = .041 sq in

Area of the case head = .131

55000 PSI internal pressure x .131 = 7205 lbs

Brass tensile strength = 65,000 PSI

65,000 X .041 = 2665

2665/7205 = 37%

Now calculate the coefficient of friction between brass and steel and the % drops a greater amount as the chamber finish improves.
Add in a little oil and so forth....

Next you don't get and can't count on total case wall grip on every shot.

Depending on a cartridge case as part of the lock up is incompetent engineering....

Again, as noted in my second post, I should have
been more explicit with the original question:

Which has the strongest receiver, the
Stevens 200 or the Marlin XS7? At any
rate, the answer came from elsewhere and the
XS7 won out. It will be a switch barrel with
an original 7mm08 and a smokeless muzzle loader
barrel in .45 caliber. Pressures on the bolt
head and action will be much relieved by the
breech plug between bolt head and powder
charge. The relatively mild pressure of the
7mm08 will stress the action more than the
ML charges. So the question is now mute since
the decision has been made for the XS7.

There has been a lot of talk here of action
failures due to overloads and/or case head
separations. Not to say it will never happen
to me, but since beginning reloading in the
mid '60's, I have never had this happen. My
cases get inspected to the point of what some
would say rediculous. Wouldn't it be prudent
for reloaders to inspect their cases a little
better and take care to ensure said cases are
loaded with the correct powder?

In the end it is all your problem danno since you are depending on hearsay for an answer.

There are other things that figure into a decision besides receiver strength.

About the obturation of the case to chamber wall, remember the test P O Ackley done where he took a Model 94 Winchester in 30-30 and removed the locking lug, cleaned the chamber of any oil and cleaned the cartridge of any oil, then fired it and it held...to prove case obturation. Something that I wouldn't want to try.

We've all heard of test made on various military rifles of WWI WWII vintage and particularly the Arisakas, but the two that stand out to me where done by fellows I know. One was a 44 Mosin Nagant. The case was of steel and it was found that any rifle powder could literally be scooped case full and bullet seated and fire with no apparent damage to the rifle. Eventually some did result in hard bolt opening, but it still worked. Finally a case of Bullseye was tried and it locked the action which required the barrel removed to open the action and the barrel chamber had a very slight bulge in it that was hard to see with the eye. The one that really stood out to me, because the action mentioned is really looked down upon, was where a gun club wanted a rifle blown up to make a video on the safety of reloading. The rifle chosen was a 6.5 Italian Carcano. The fellow chosen to "blow" the rifle and went through all the rifle powders as described in the aforementioned Mosin 1944 with full case fulls with on damaging results. Next the case full of Bullseye was chosen and to their amazement the rifle still held. Determined a case full of C4 finally exploded the rifle with spectacular results. Needless to say I still would not choose either of those actions for a custom rifle. I will say the Mosin Nagant does seat the cartridge all the way to the face of the rim with only a small cut away for the small extractor. Seems like a decent design. I believe the 30-40 Krag also seats it's cartridge similar, but the bolt only had one lug.

I don't see much difference between the Savage and Marlin action and makes me wonder who really makes the Marlin especially with talk of Marln's demise.

"About the obturation of the case to chamber wall, remember the test P O Ackley done where he took a Model 94 Winchester in 30-30 and removed the locking lug, cleaned the chamber of any oil and cleaned the cartridge of any oil, then fired it and it held...to prove case obturation. Something that I wouldn't want to try. "

Then how do the various blow-back actions work?

[QUOTE]Originally posted by DougH9:
"About the obturation of the case to chamber wall, remember the test P O Ackley done where he took a Model 94 Winchester in 30-30 and removed the locking lug, cleaned the chamber of any oil and cleaned the cartridge of any oil, then fired it and it held...to prove case obturation. Something that I wouldn't want to try. "

That's a good question. Now some of them do work by a mechanical means. In theory the Browning type barrel lock up on such pistols as the 1911 is classified as a blow back. Then taking something like the Walther PP, that is just a straight non locking blow back. With the Model 94 we can't say that a time delay works the action because Ackley would have been in trouble still holding the rifle. Like I said I would never try his test. They did say that him holding the lever closed was enough to keep the bolt from moving.

quote:

Then how do the various blow-back actions work?

Low powered cartridges, heavy bolts and heavy recoil springs.

quote:

Originally posted by SR4759:
In the end it is all your problem danno since you are depending on hearsay for an answer.

There are other things that figure into a decision besides receiver strength.

Problem? There will be none.
Hearsay? There's much of that right here....in
the negative.

Other things that "figure" have already been
figured....and proven....by others as well as
myself.

I'll not be attempting to push a 275gr bullet
3300fps with 140gr IMR4350 like the Bad Bull
muzzleloaders can do, anyway.

Hi SR4759
We can be nitt picking about minor details. But i realy dont think you understand my point.
I dont calculate chamberfriction as a safetyfactor in actionstrencth calculation. In an actionstrength calculation i always use zerro friction, to determin "worse case"
The varyation in chamberfriction as you also admit is pretty unpredictable, and can in the most pesimistic senarios carry from nearly 0lbs up to 2660lbs. in your brass yieldstrength calculation. This varyation in boltthrust would in a asymetric locking equals a different actionflexing, causing change in barrelwhipping.
The same bolt thrustvaryation in a symetric locking would have pracktically no action flexing effect, therefor almost no change in barrelwhipping, therefor almost no change in POI

quote:

quote:
Then how do the various blow-back actions work?



Low powered cartridges, heavy bolts and heavy recoil springs.

I know how they work...what I was asking is; how do...or could...blow-backs work using the theory that straight walled cases stick in the chamber.

I don't think they do; a Ruger 10/22 or Thompsen 45ACP carbine is proof of that.

Finit element analysis and force measurements
both show the case staying forward until 40 KPSI or so. If ypo have a medium pressure caetridge in a chamber with headspace the primer will protrude with moderate pressure and be fully seated at full pressure. Ackley used an improved 30/30 when he fired the 94 action.
He was trying to prove that the improved case
had less back thrust. Of course it can't. If he had increased the load he would hve had a different conclusion.
Once brass starts to stretch it has little
strength, as pointed out earlier the brass
that stretches is a thin section. Where friction
enters the picture is the wholebody of the.. case being held forward.
Good Luck!

quote:

Originally posted by DougH9:

quote:

quote:
Then how do the various blow-back actions work?



Low powered cartridges, heavy bolts and heavy recoil springs.

I know how they work...what I was asking is; how do...or could...blow-backs work using the theory that straight walled cases stick in the chamber.

I don't think they do; a Ruger 10/22 or Thompsen 45ACP carbine is proof of that.

Choose another example then the 45 acp because it's not a straight walled cartridge, but I know what you mean.