Rolling Block 7x57 SM

[Bart B.]

Best article on barrel pressures I know of:

http://kwk.us/pressures.html

SAAMI's web site has all the details about both crusher and transducer system they use. Cannot find details on CIP systems.

 

[Slamfire]

Not trying to antagonize, but wouldn't we be hearing about guys getting killed by old guns with FACTORY ammo all the time if there were such a monumental risk as you seem to put it?

Where is the database for Police shootings? You know there has been a lot of fuss about Police shootings, and it turns out there is not a Federal Database of Police shootings, so no one can answer just how many people are shot by Cops. Neither is there a database of Cop killings. The lack of a database allows some groups to claim that Cops don’t shoot people, but Cops are being shot all the time. But other groups claim that Cops shoot people all the time, but that people don’t shoot Cops. So which is it?


You know, until I watched Alaskan Aircraft Investigations, I had no idea that many private aircraft were crashing. I am not going to try to find the NTSB database, but, no one ever told me about these planes crashing. And many of them are due to pilots doing stupid stuff, such as a pilot buzzing a wedding party in a pasture, but hitting the forest beyond. Imagine getting married and seeing your Dad die on the same day!

It would be nice if laws were passed, billions spent, so that all firearm misfires, accidents, blowups, were reported to me, but, this is not happening. There is no database out there on firearm blowups, the only blowups reported on the web are incidental, and hotly debated. Since reports are not conducted by trained investigators, the causes become highly speculative.

Slamfire, you seem to be talking out of both sides of your mouth right now. Unless I'm an idiot, which is possible. So either you can "never prove any gun is sound or safe and no old gun should ever be fired" or "manufacturers know there's lots of old guns lying around and take that into consideration." Which is it?

As for Corporations, they take calculated risks all the time. The tobacco companies knew their products killed people, but they calculated the risk of lawsuits, and the cost, and came to the conclusion that the profits from sales would exceed the cost from lawsuits. And so it has been. Corporations also regularly violate laws where the fine is less than the profit from the illegal behavior. Corporate decisions are based on profit, and obviously, ammunition companies believe that they will make more money selling ammunition, even though there is a risk that their ammunition will blow up some antique.

You did the prudent thing by taking it to a gunsmith and having it examined, but you should have gotten his written opinion on the safety of the weapon. If nothing happens, then nothing happens. But if something happens, you will carry all the liability for subsequent events. I am of the opinion that you cannot prove any antique is sound, and therefore shooting antiques is a calculated risk, which sometimes, people lose.

You can check out these reports of old rifles blowing up and hurting people:

Catastrophic Failure - Swedish Mauser m/1896
http://castboolits.gunloads.com/showthread.php?106437-Catastrophic-Failure-Swedish-Mauser-m-1896

I don't remember if I ever posted these photos in this forum but with the other topic of the Spanish 1916 catastrophic failure http://castboolits.gunloads.com/showthread.php?t=34549 coming up I thought it might be a good idea to have this as a separate subject.

The difference between the Spanish 1916 failure and this Swedish Mauser is we know exactly what caused the Swede to come apart. It was a double charge of fast pistol powder. The rifle resides in the UK so these photos were obtained for me by another very knowledgeable Swede collector who's USAF duty station is in the UK.

The Mauser m/1896 was taken out of general military service in Sweden some 12-15 years ago due to a bolt lug failure killing a young Swedish soldier. There are some m/94 carbines in use by the Livguard who has duty at the royal palace in Stockholm and their rifles are carried locked and loaded so they are not ceremonial. Swedish Mausers do fail in normal use many times for reasons that are not obvious. I would prefer to urge caution and care when handloading or shooting rifles that are 100+ years old. Metal fatigue is cumulative. If you feel the need to hotrod a Mauser do it with a 98 action.

Sheared Bolt Lugs - Swedish Mauser
http://castboolits.gunloads.com/showthread.php?34532-Sheared-Bolt-Lugs-Swedish-Mauser

m/1896 Swedish Mauser in Australia. Details of failure unknown to me.

Those of you with metallurgical experience are most welcome to comment... though I know its hard to make a definitive statement based on such limited information.

As with the 1893 Mauser photos I post these photos to illuminate the reality that seemingly strong and sound rifles suffer catastrophic failures and sometimes people are killed as a result. What exactly caused this incident, had it killed the shooter, would be immaterial to his widow and children. Dead is dead.

None of this will make a difference if you are one of those people who think they are invincible. Are you invincible? I recently talked to one guy at the range about the dangers of smoking. Did you know that about half the people who smoke die from smoking related illnesses? This guy, said he had smoked three packs a day for 30 years and only quit because cigarettes had gotten so expensive. If the prices came down, he would start back up again. He also said he had skin cancer, and that was fixed. He had a heart attack, and that was fixed, and he had two hip replacements. I could tell, he thought he was invincible. If something broke, medical science replaced it, so instead of these alignments being warning signs, they were proof he was invincible. I can tell he is of the type that believes that which does not kill me, makes me stronger. Since smoking had not killed him, it was not going to kill him. And even if you yelled at him in his coffin do you believe it now? he was not going to change. I like this guy, he is nice gentleman, but, he is a little off about risk.



If you really want to shoot your rifle, go ahead. If nothing happens, then nothing happens. If something happens, please tell us all.

 

[eastbank]

i have had enough. eastbank

 

[Gordon]

I had a 90% as new post 1901 Remington RB in 7mm and the headspace and everything was as left from the factory. Somewhere long ago I bought 500 rounds , in a small wooden crate, of FN manufactured 7mm SM marked (Spanish Mauser) cartridges. These had cupro nickle bullets and when fired at rock or decomposed granite walls I found they would "spotlight" when they hit ! They were right to the sights as marked and I had fun shooting them to maybe 600 yards, with good accuracy and perfect extraction. They seemed a little "warmer" than commercial remington ammo I used at the same time by the performance way out there. I started carefully miking the unfired and fired cartridges and made a chamber cast to compare. The SM marked cases had a longer neck and slightly shorter datum line to the shoulder than commercial cartridges. I read that 7mm Spanish Mauser were indeed slighly different to the later 7mm Mauser dimensions. So there is that ! FWIW I sold that #5 last year, with the correct bayonet, for $1500 as it was that nice an example ! They are very neat and if the headspace is good and the pin tight I would have no qualms with US made ammo, at least.

 

[Dog Soldier]

Here is a link to a discussion on the Remington Society. They were discussing the Rolling Block and the 7MM Mauser.

http://www.remingtonsociety.org/forums/viewtopic.php?f=5&t=4500

 

[Jim Watson]

How come nobody reports the early versus late headspace difference for 7mm Mauser in MAUSERS?
The round came out ca 1892, selling rifles from 1893 on. Yet the only place I have seen funny headspace mentioned is for Remington models of 1897 and 1902. Might it be a Remington thing, not a Mauser thing?

 

[earplug]

Reminds me of various old pistol rounds that are still loaded to 100 year old specifications. Factories still crank out the old rounds at the old specs to keep olds guns from grenading. If there were real issues various resellers and ammo makers would be in trouble.

 

[barnbwt]

I'll just mention that I've heard of exactly one rolling block failure; a Swedish 45-70, which some fool blew apart (to his own fatal end) cramming in assorted chamberings, some of them with a hammer (the pile of fired/unfired cases adjacent ranged from like 2" to 3.5" in length)

The actions are quite tough, as far as handling abuse. However they are not rigid, since any play or flex in the hammer/block interface and their pivots serves to open the breech face during firing --this means that they are more susceptible to stuck cases and case head failure due to case stretching while pressurized, features most commonly found in higher-pressure rounds.

Further, when failures do happen in a rolling block, they tend to be more hazardous; the so called 'gas handling' characteristics. There is nothing at all between the breech block and the shooter's face, so a ruptured case vents tens of thousands of psi of hot, burning gas inches from the user. That said, the action itself is resilient against rupture when this happens because the gas can vent so easily, it is unable to blow the action apart. But in the event of a severe overpressure (like Lenny man-handling cape gun cartridges into grampy's rifle) violent enough to shear the breech block pivot, this part will be thrown straight back into the user's face under the full power of the burning powder. More modern designs incorporate fail safes to prevent this kind of catastrophe.

So, the long and the short of it is, with modern metallurgical alloys (which the 7x57 guns had, I understand), the rolling block is capable of handling impressive levels of bolt thrust before its parts fail (like that pivot axis). However it is fundamentally ill-suited to supporting high-pressure cartridges compared to other designs, which is why the safest course of action is to limit shooting to lower pressure cartridges (45-70) or to opt for lower pressure loadings (7mm Mauser), so as to avoid all risk of case head failure & gas venting, which increases as more guns wear out and become loose in the breech.

Even the 7x57 'weak' loads are remarkably powerful, at least enough for me to recognize what kind of a game-changer these new "smokeless" powders must have been at the turn of the century. Very flat shooting, even well beyond what any soldier using rolling block sights could hope to hit, but also very comfortable from a lightweight rifle with a steel butt plate.

TCB

 

[barnbwt]

Reminds me of various old pistol rounds that are still loaded to 100 year old specifications. Factories still crank out the old rounds at the old specs to keep olds guns from grenading. If there were real issues various resellers and ammo makers would be in trouble.

And at the same time, vintage surplus ammo still being shot has seen its powder deteriorate and become more violent in combustion than was originally intended. And those 100 year old pistols have seen a lot of hot, unwise, or defective ammo over the years in many cases (old burp guns are the best example of a life of abuse; often dozens of out of battery detonations and at least several squibs blown through the barrel)

TCB

 

[tark]

Holy dog you-know-what! This is about as far off course as I have seen a thread go in a long time. It's about CE310QTs 7mm rolling block, remember?

Slamfire, Remington smokless powder rolling blocks were made from steel and case hardened. Surface heat treated. It was easy to do, strong, it worked, and held up well to the cartridges of the day. They were chambered for 7mm Mauser, 7.62X54 Russian, 8mm Lebel, 30-30, 30-40, and perhaps 7.65 Argentine. Those first three are in the 45,000 PSI range and the guns never had a problem with them. Remington never made any in 30-06. I assume that 50,000 PSI was a bit too much for the action. I have never seen one in 7.92 X 57 so I assume the same is true for that caliber.

CE310QTs gun, having been proven to have proper headspace, is as safe to fire as any other gun.

 

[tark]

BTW, Slamfire, your ballistics for the 7mm with a 175gr bullet are a little off. The old military load pushed that bullet to 2490 FPS.

 

[Slamfire]

BTW, Slamfire, your ballistics for the 7mm with a 175gr bullet are a little off. The old military load pushed that bullet to 2490 FPS.

My source for 1890's 7mm service rifle ammunition velocities came from:

Whittemore, J.M. (1899). Report Of Test Of Mauser Arms And Ammunition Relative To Pressures And Velocities.. US Govt.Print.Off,.

http://books.google.com/books?id=YgFHAQAAIAAJ&pg=PA179#v=onepage&q&f=false

Pg 28, states that the 7mm Mauser Cartridges captured in Cuba had an initial velocity of 2200 fps.

When you get into Appendix 11, the Frankfort Arsenal contribution by Col Whittmore, you will find the weight of the Mauser projecticle is 173 grains. Colonel Whittmore tests German and French ammunition in the “Mauser pressure gage” and the velocities he recorded were 2,166 and 2127 fps. Col Whittmore than uses American powders to develop loads that give 2200 fps with German and French components

Clearly we are reading about tests with the M1893 small ring rifle in 7mm Mauser and a service bullet of 173 grains at 2200 fps. Velocities and bullet weights of course have varied, but in the late 1890's when these Rolling Blocks were being made, these are the velocities of the period.

I do not consider 1901 vintage steels to be advanced or of high quality. The technology of the day did not produce clean steels. Period steels were plain carbon steel, not alloy steels. If someone has information that Remington Rolling blocks were made of alloy steels, please post the data and the source.

This is worth reading, even if the rolling blocks are from an earlier period:

Historical and Experimental Investigations of the Pressure Characteristics of the 8x58 Rimmed Danish Cartridge

http://dutchman.rebooty.com/GB8x58RD.html

And then there is this comment on WW1 steels:

Rolling Block strenght

http://castboolits.gunloads.com/showthread.php?52526-Rolling-Block-strenght/page2


"The Remington catalog of 1875 is the first that lists barrels of decarbonized steel for rifle barrels. This is what we call mild steel today. This steel is soft like Damascus, but more ductile. You'll see a lot more repairable dents or gouges in these steels than in a more modern steel. The barrels were rolled from solid metal , without weld or seam. They were rolled to size bored out, then turned and ground proved with a heavy charge of powder and a solid slug of lead. "

"The April 1897 Remington Arms Co. catalogue introduced “Remington steel” barrels on the Remington Hammerless Doubles. Prior to that date shotguns were only offered with Damascus barrels of varying qualities by grade. Two types of steel barrels were introduced at that time: “Remington Steel” and “Ordnance Steel”"

"Remington Steel was the lower grade and was sold for the same price as the ordinary Damascus barrels on A-grade shotguns. It was made “in-house” at the Remington factory."

""Ordnance Steel" is a higher grade, and was especially recommended for heavy charges of nitro powder. The tensile strength of this steel is 110,000 lbs., and elastic limit 60,000 lbs., this being greatly in excess of any strain to which barrels are subjected with reasonable loads of nitro powders. It was available in some rifles and shotguns."

I did not know this until I looked as a response to your post. However, I have worked with Steel my entire professional career. I was the head of a Testing Lab in a steel manufacturing facility for 4+ years. During that time, I was provided a ferrule from a WW1 fighter airplane for testing. It was made from what was labeled "high strength steel" (the label was from WW1). I tested it and found that it was lower strength than the lowest strength steel that can be bought today. In addition, it had a lot more impurities than would be allowed today, particularly sulfur. (PS. "today" means from about 1975 to 1980). I know that steel has continued to increase since then in strength, ductility, and all the other desirable characteristics we use without thinking about it.

The early Remington rolling blocks were made from iron.

 

[krinko]

If you are going to fire 7x57 in your rolling block, you might want to look at these numbers. Made with dial calipers using ammunition on hand.
1. 7x57 DWM 1937---rim .4735" and head .469"
2. 7x57 FN 1970---rim .474" and head .4685"
3. 7x57 Federal 2012---rim .468" and head .464"
4. 7x57 Federal 2012, fired in M1908 DWM Mauser---rim .468" and head .4645" and just above the web .469"
The measurement above the web in 4, shows the SAAMI spec case trying to assume the European standards, which could be interesting in a rolling block with a European chamber.
-----krinko

 

[tark]

Slamfire my source was cartridges of the world. Your source trumps mine! I just learned something. The Black powder rollers were made from iron. The smokeless ones from steel, of doubtless poor quality compared to modern, but steel nevertheless. The casehardning rendered it usable for it's intended purpose. I made mine out of 4140 and had it heat treated to RC40. it eats 30-06 factory rounds. The fired cases can be run into a full length die with one finger and very little effort. There is no "spring" in my action. With modern steel, rollers can handle just about cartridge.

Anyway, thanks teaching me something I had misinformation about.

 

[Slamfire]

I made mine out of 4140 and had it heat treated to RC40. it eats 30-06 factory rounds. The fired cases can be run into a full length die with one finger and very little effort. There is no "spring" in my action. With modern steel, rollers can handle just about cartridge.

Without a doubt a rolling block can be engineered to withstand any modern cartridge, it is a matter of examining the loads and the load paths and determining the structure necessary to support. Modern alloy steels are superior to the plain carbon steels of 1900, in all respects. Strength, fatigue lifetime, shock impact, etc. 4140 is an excellent alloy steel, been used on millions of firearms. A metallurgist bud of mine recommended 4340 as the nickel content increased the fatigue life.

The Black powder rollers were made from iron. The smokeless ones from steel, of doubtless poor quality compared to modern, but steel nevertheless. The casehardning rendered it usable for it's intended purpose.

And you have hit on the main point of this, these older guns are an unknown. What we basically know is that they are made out of inferior materials and the quality of period steel, and subsequent heat treatments are highly variable. Therefore there is risk of structural failure with these things if they are pushed too hard. While ammunition manufacturer's have toned down some loads, they have to balance profits versus risks. One risk would be loading all 7mm cartridges down so they all are safe in 1900 rolling blocks, the risk is that those with more modern rifles would not be interested in buying anemic ammunition. Another risk is the potential of a lawsuit when someone stuffs a modern cartridge in a weak antique. I think the risk of a lawsuit is less than the risk of the customer base not buying the cartridges.

One of the references I provided showed that Swedish rolling blocks were loaded to less than 30,000 psia. I believe these antique rolling blocks are reloading only propositions and reloading to light loads.