For those of you who think the Krag has a weak action...


PDA






.455_Hunter
November 11, 2009, 03:16 PM
http://gunbroker.com/Auction/ViewItem.asp?Item=145281992

For those who love the unique and want something different than your shooting buddies please consider this well executed Krag Conversion to .405 Winchester Caliber.

:)

If you enjoyed reading about "For those of you who think the Krag has a weak action..." here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
saturno_v
November 11, 2009, 03:28 PM
I don't know much about the Krag action but the 405 Winchester is a low pressure round (I believe around 30,000 PSI SAAMI specs).
The 30-40 Krag should be higher pressure.

Yes the 405 Win is powerful but low pressure nevertheless.

natman
November 11, 2009, 03:44 PM
The 405 Winchester is in the same ballpark as the 30-40 Krag in pressure, so drawing conclusions about the strength of the action because one guy converted one and it isn't in splinters yet is a bit of a stretch.

saturno_v
November 11, 2009, 03:54 PM
natman

Actually I think the 30-40 Krag is a bit higher pressure than a 405 WCF...

SlamFire1
November 11, 2009, 03:56 PM
Pre 1900 metallurgy is primitive beyond belief. They barely understood phase changes, phase diagrams, transition temperatures, you name it. Pre 1920 metallurgy was inexact science and it is not till you get into the 30’s does metal science become a mature science.

Just saw a show on the Titanic. They made a big point on how much slag was in the wrough iron rivets. That was 1912.

US Krag’s were all built around 1898. The plain carbon steels used then are now considered suitable for rebar. These rifles have been known to crack the single locking lug with 30-40 Krag ammo. I saw one cracked lug at the range. A 30-40 Krag will push a 220 bullet 2200 fps. That is pretty mild in today’s world.

This guy increased the bore diameter which should make a difference in total load, or maybe total impulse on the bolt.

I would not buy the rifle even though the workmanship looks decent. I think it is an accident waiting to happen.

This might be a feasible conversion if he had used a Norwegian krag from the 30’s.

Avenger29
November 11, 2009, 04:13 PM
And remember folks, just because somebody came up with a harebrained idea and made it, does not automatically make it a good idea to try it out for yourself, nor does it prove anything.

Kernel
November 11, 2009, 07:09 PM
SAAMI spec on the .405 WCF is 44,000 psi. Pressurewise, that puts it between the .30-30 (42k) and the .300 Savage (47k).

Art Eatman
November 11, 2009, 08:30 PM
The rule of thumb for any single-lug bolt-gun or a rear-locking action like the Winchester Model 94 is about 40,000 psi. At or below that you might get cracking, but it's not gonna come all apart at the seams...

Gordon
November 11, 2009, 08:52 PM
FWIW Col. Cooper had more 30-40 Krag ammo stashed in his bunker the last couple years before his demise than any other caliber. He a nice Krag sporter with ghostring that he could use quite well! His "rough rifle" of choice. I have one too, for the heck of it.Sure is slick and handy and reliable on anything in the Americas though......

Jim K
November 11, 2009, 09:07 PM
Well, the strength of an action does not depend on how many rifles or ammunition of that type someone had stashed away.

The .405 is a higher pressure round than the .30-40 as well as having a slightly larger internal base diameter. The base size is critical, because it determines the amount of actual pressure pressing on the breech face. Pressure per square inch is good enough for comparison, but when determining the suitability of a given action, the critical figure is the absolute pressure at the breech face.

Jim

RonE
November 11, 2009, 10:44 PM
That is a great looking rifle. It has been modified to feed the modified .405 cartridges which doesn't appeal to me. I also notice that it looks like a $1,500 rifle but no one seems to be in the market of such a combination of oddities. I notice no bids. It was quite and artist that built that gun.

jim in Anchorage
November 12, 2009, 02:45 AM
I wonder how much bolt face pressure that straight wall .405 really has. In my handbook for shooters & reloaders volume 1 by Ackley. he rechambered a94 Winchester to a improved 30-30 with minimum case taper. The locking lug was removed leaving only the finger lever to support the bolt. It was then fired several times with 40,000 psi loads, with no damage to gun or brass. Apparently the straight wall case clings tightly enough to the chamber that back trust is non existent, at least to a psi level that would separate the solid base.

Maverick223
November 12, 2009, 11:46 AM
The base size is critical, because it determines the amount of actual pressure pressing on the breech face. Pressure per square inch is good enough for comparison, but when determining the suitability of a given action, the critical figure is the absolute pressure at the breech face.Very true, that is the only aspect that actually regards the action and not the bbl. The bolt thrust would be significantly higher in the .405Win., and for that reason I wouldn't feel comfortable with the rifle (not knowing if it is truly safe).

The locking lug was removed leaving only the finger lever to support the bolt.That is incredibly dangerous, and if it really was tried I am surprised that someone was not hurt or killed in the process.
Apparently the straight wall case clings tightly enough to the chamber that back trust is non existent, at least to a psi level that would separate the solid base.There is no way that friction can support that kind of pressure (straight walled or not), it is thousands of pounds of force pushing back, you must contain the entire cartridge (save for the obvious...the projectile) in a very stout pressure vessel, this must include the rear of the cartridge.

:)

jim in Anchorage
November 12, 2009, 04:16 PM
That is incredibly dangerous, and if it really was tried I am surprised that someone was not hurt or killed in the process.

I think P.O Ackley would know how to conduct a gun test safely. You DO know who he is, right?
There is no way that friction can support that kind of pressure (straight walled or not), it is thousands of pounds of force pushing back, you must contain the entire cartridge (save for the obvious...the projectile) in a very stout pressure vessel, this must include the rear of the cartridge
No need to belive me. Get P.O. Ackley's hand book for shooters and reloaders,volume 1, copyright 1962, by publishers press. Chapter on pressure. pages 137-149.

R.W.Dale
November 12, 2009, 05:04 PM
I think P.O Ackley would know how to conduct a gun test safely. You DO know who he is WAS, right?

You guys need to look at this mans work for what it is. A work on internal ballistics and rife smithing based on what was known a half century ago. Much of his work particularly as it relates to internal ballistics has time and time again been proven to be completely erroneous and based on the same false assumptions everyone used 50 or 60yrs ago. Particularly his pressure sign masking AI'ing of cartridges.

I wonder how much bolt face pressure that straight wall .405 really has.
he locking lug was removed leaving only the finger lever to support the bolt. It was then fired several times with 40,000 psi loads,

Two words. STRAIGHT BLOWBACK

try to hold the bolt closed after firing a 9mm or 45acp carbine. After you get your thumb sewn back on you'll realize that just cause someone wrote a book and gets their name mentioned in magazines doesn't make their entire work correct

Maverick223
November 12, 2009, 05:23 PM
I think P.O Ackley would know how to conduct a gun test safely. You DO know who he is, right?If the above account was correct, apparently he did not. Never met...but I know of him very well...Your point? Do you think he was a faultless god...superhuman in all of his endeavors? I can't help but notice that none of his cartridges have gained mainstream success...I suppose everyone else just doesn't realize his genius. I am not saying that he didn't make some improvements or that all of his work was flawed...but he made mistakes just like everyone else.

No need to belive me. Get P.O. Ackley's hand book for shooters and reloaders,volume 1, copyright 1962, by publishers press. Chapter on pressure. pages 137-149.Is this where he states that "a rifle needs no containment at the base of the cartridge due to case friction"? I don't think that anyone with any general knowledge of firearms mechanics, pressure vessels, fluid dynamics, or any form of basic physics would be stupid enough to make that claim.

try to hold the bolt closed after firing a 9mm or 45acp carbine. After you get your thumb sewn back on you'll realize that just cause someone wrote a book and gets their name mentioned in magazines doesn't make their entire work correctExactly, and that is with a low pressure, low bolt thrust pistol cartridge. A rifle cartridge is MUCH more severe. If a rifle (firing a full power rifle cartridge) used a blowback mechanism like a pistol, the weight of the slide or bolt would be astronomical (over 100lbs for some rifles).

:)

jim in Anchorage
November 12, 2009, 05:46 PM
You guys need to look at this mans work for what it is. A work on internal ballistics and rife smithing based on what was known a half century ago. Much of his work particularly as it relates to internal ballistics has time and time again been proven to be completely erroneous and based on the same false assumptions everyone used 50 or 60yrs ago. Particularly his pressure sign masking AI'ing of cartridges

I never defended every thing the man wrote. But the fact remains he DID remove the bolt from a 94, he DID fire it with a straight case 30-30 developing 40,000 psi, and the gun and case DID survive. In fact the only abnormality noted was the primer protruded somewhat-which makes perfect sense-the firing pin shoved the case forward, the pressure locked it in place and the primer backed into the available headspace

This was not theory, guesswork or speculation. It was a actual experiment carried out on a real gun.

Two words. STRAIGHT BLOWBACK

try to hold the bolt closed after firing a 9mm or 45acp carbine. After you get your thumb sewn back on you'll realize that just cause someone wrote a book and gets their name mentioned in magazines doesn't make their entire work correct

No I would not try to hold a 9mm or .45 in the chamber for the simple reason it dosn't GENERATE ENOUGH PRESSURE TO LOCK THE CASE. Have you not noticed blow backs are confined to low pressure cartages?

R.W.Dale
November 12, 2009, 05:55 PM
No I would not try to hold a 9mm or .45 in the chamber for the simple reason it dosn't GENERATE ENOUGH PRESSURE TO LOCK THE CASE. Have you not noticed blow backs are confined to low pressure cartages?
__________________

9mm Luger +P 38,500psi
40 S&W 35,000psi
he DID fire it with a straight case 30-30 developing 40,000 psi,

according to your theory then the margin for saftey is only 1500psi of course this assumes PO Ackley had any idea what the pressures involved in the test were beyond pretty much guessing

Really then why are the Handi rifle folks stretching the piss out of frames frames when they shoot a bunch of warm 500magnum loads?

Bolt thrust is an easily calculated variable that always increases as pressure does. The brass itself WILL not contain pressure at the case head if unsupported

jim in Anchorage
November 12, 2009, 06:08 PM
This seems to be controversial. Before anyone else replays let me make two things clear;

#1 it only applies to straight wall,clean cases. No oil can be present in the chamber or on the case.
#2 It only applies till pressures exceed the yield point of the brass; commonly accepted at approximately 40,000 psi even by us modern, enlightened folk.

jim in Anchorage
November 12, 2009, 06:35 PM
9mm Luger +P 38,500psi
40 S&W 35,000psi
I am not a pistol guy but I am not aware of any straight blowback design meant for 38,500 psi loads.

this assumes PO Ackley had any idea what the pressures involved in the test were beyond pretty much guessing
Factory loads.

R.W.Dale
November 12, 2009, 07:35 PM
Just about any 9mm carbine other than the marlin is going to be a straight blowback operated arm that'll digest 9mm+p without a hiccup

factory loads? What cartridge? A straight walled 30/30 50years ago was a 38/55 a cartridge loaded to much lower pressures than 40,000psi. Either way you really really contradict your own theory with the statment that 35,000 to 38,500psi isn't enough pressure but 40k+ is too much

plus a m94 with the bolt cut off isn't exactly unlocked. The hand lever and the hammer are both at a state of conciderable of mechanical advantage resisting the bolts ability to be pushed rearward.

Of course none of this has any bearing whatsoever on the safety of a Krag in 405

Maverick223
November 12, 2009, 07:35 PM
The brass itself WILL not contain pressure at the case head if unsupportedMy point exactly.

I am not a pistol guy but I am not aware of any straight blowback design meant for 38,500 psi loads.I take it that you are not aware of the .357Sig cartridge then. It has a (non +P) SAAMI specified maximum pressure of 40,000psi, so I am sure that some factory defense loads exceed 38.5kpsi.

The hand lever and the hammer are both at a state of conciderable of mechanical advantage resisting the bolts ability to be pushed rearward. The only thing that might keep one from having the bolt come undone during firing.

:)

jim in Anchorage
November 12, 2009, 08:35 PM
Just about any 9mm carbine other than the marlin is going to be a straight blowback operated arm that'll digest 9mm+p without a hiccup
Examples?

factory loads? What cartridge? A straight walled 30/30 50years ago was a 38/55 a cartridge loaded to much lower pressures than 40,000psi. Either way you really really contradict your own theory with the statment that 35,000 to 38,500psi isn't enough pressure but 40k+ is too much

A factory 30-30 with the normal case taper. As you know, the 30-30 headspaces on the rim. When fired the case walls conform to the straight chamber
Of course none of this has any bearing whatsoever on the safety of a Krag in 405
Wrong. The action only contains the back thrust; The barrel contains the pressure of the body of the cartridge.

R.W.Dale
November 12, 2009, 09:39 PM
Examples?

Ruger pc9 & 40
keltec sub 2k
high point 995
beretta storm
9mm ar15's
and just about any other 9mm carbine you can think of
A factory 30-30 with the normal case taper. As you know, the 30-30 headspaces on the rim. When fired the case walls conform to the straight chamber

sounds like you're describing a fireform load with a grossly undersized bullet IE no pressure

Jim K
November 12, 2009, 10:34 PM
When a round is fired, the case expands and the pressure pushes it against the chamber wall. But unless the case is made of some material that cannot stretch ("unobtanium"), the base of the case will be pushed back by the same pressure, stretching the case. If headspace allows, the case will stretch far enough to break. While this is rarely dangerous to the shooter, it will tie up the rifle, which is why the military puts much more emphasis on checking headspace than most civilians. In civilian life, an inoperable rifle rarely results in the death of its user.

So, no, when high pressures are involved, the case clinging to the chamber wall will not reduce pressure on the breech face "tightly enough ... that back trust is non existent".

For a case like the 7.62 NATO, the absolute pressure on the breech face is roughly 5000 pounds, and it is applied suddenly in a blow, not a gentle push. For an idea what that means, imagine a rifle with its butt on the ground and barrel pointing upward, with a steel rod down the barrel. On the rod is a platform onto which a Ford F150 Crew Cab pickup truck is dropped from a crane. Of course, such a thing could only be imagined, but it serves to give an idea of the kind of pressure involved in an ordinary rifle.

Jim

jim in Anchorage
November 12, 2009, 11:39 PM
Ruger pc9 & 40
keltec sub 2k
high point 995
beretta storm
9mm ar15's
and just about any other 9mm carbine you can think of

O.k. there are blow back 9mm. But when does the base exert pressure on the bolt? At the full 38,500 psi or at some point below peak pressure? Also a 9mm is a poor example in this argument. The ratio of case wall[which is doing the holding] to base is much higher in a 30-30 then a 9mm. The 40,000 psi is not a absolute figure; a short fat case will produce backtrust at a lower psi then a long thin one.

sounds like you're describing a fireform load with a grossly undersized bullet IE no pressure
The shoulder and neck where left alone. Only the case body in the chamber had the taper eliminated. It was a 30 bullet in a 30 bore. This is the whole concept of improved cartridges, some times with the neck blown out.

I sense some skepticism here that brass can hold 40.000 psi. It is very important to remember we are dealing with SHEAR strength, not BURSTING strength.
Picture a 3 by 3 ft piece of cardboard fastened by the edges to a open frame. Try to put your fist though it. Easy. That is its bursting strength.
Now take the same piece of cardboard and try to pull it straight apart. Impossible. That is it's shear strength.

Maverick223
November 12, 2009, 11:47 PM
I sense some skepticism here that brass can hold 40.000 psi.Brass can hold 40kpsi without any trouble...but it must be a great deal thicker than the brass used in cartridges. :D Shear is often more devastating than other forces. FWIW the "bursting" that you refer to is a type of shear known as punching shear or two-way shear. Ask me how I know. :)

jim in Anchorage
November 13, 2009, 12:03 AM
Brass can hold 40kpsi without any trouble...but it must be a great deal thicker than the brass used in cartridges. Shear is often more devastating than other forces. FWIW the "bursting" that you refer to is a type of shear known as punching shear or two-way shear. Ask me how I know.

Is not part of the base in a Mauser type bolt unsupported? In calipers that develop 60,000 psi?

Maverick223
November 13, 2009, 12:12 AM
Is not part of the base in a Mauser type bolt unsupported? In [cartridges] that develop 60,000 psi?Sure, and part of the Coliseum in Rome has fallen. That doesn't mean that the remainder of the bolt head is insufficient or that people don't show up to see what is left of the Coliseum.

:)

jim in Anchorage
November 13, 2009, 12:22 AM
Regardless the unsupported portion of the base, by its self, is withstanding 60,000 psi.

Maverick223
November 13, 2009, 12:28 AM
Regardless the unsupported portion of the base, by its self, is withstanding 60,000 psi.It is subjected to MUCH less force than a fully unsupported case head. It is akin to a cantilever, the longer the span the exponentially greater the force.

:)

jim in Anchorage
November 13, 2009, 01:59 AM
This may never be resolved to everyones satisfaction unless I duplicate Ackleys experiment[NOT WITH MY 1894:eek:] And I understand not all of his ideas have stood up to latter investigation. However, unless he made the whole thing up,this was a direct observation of a controlled experiment with the results I passed on.
This little chat has been going on for close to 10 hours and I am running out of things to add [Although it certainly was interesting]:)
I highly recommend you get his books, handbook for shooters & reloaders V 1+2 [may be hard to find-probably out of print.] Makes very entertaining reading weather you agree with him or not. If nothing else the man lived and breathed guns.

Maverick223
November 13, 2009, 02:16 AM
If nothing else the man lived and breathed guns.Now that I agree with. All I want to leave you with is that if the experiment occurred as you stated (and I don't believe that you made it up...but others could have embellished the tale), it was very dangerous, whether it worked or not.

Now back to the regularly scheduled programming... :)

jim in Anchorage
November 13, 2009, 02:39 AM
Now that I agree with. All I want to leave you with is that if the experiment occurred as you stated (and I don't believe that you made it up...but others could have embellished the tale), it was very dangerous, whether it worked or not.

Ahh will this never end! I would assume the gun was held in a fixture and fired remotely. After all, he did blow up[and I mean BLOW UP] several military actions to test their relative strength with no loss of life or limb that I know of.
getting a lot of rain from that storm down there?

Maverick223
November 13, 2009, 02:54 AM
getting a lot of rain from that storm down there?Been raining for the last 2 days straight. :banghead:

jim in Anchorage
November 13, 2009, 03:18 AM
Yeah sometimes I HATE THE COLD but no hurricanes here.

StrawHat
November 13, 2009, 07:36 AM
Nice rifle, wish I had the money to buy it.

The front sight is relatively new, I have the same one on my 405, so I wonder if the work was done recently and if so, by whom?

A whole lot to like in that rifle. Have to disagree that it is on a par with the 45-70. Firing 300 grain bullets of decent alloy, the 40 caliber will give better penetration when loaded to the same velocity. I also find the recoil to be easier on the shoulder.

Nice looking rifle.

Maverick223
November 13, 2009, 11:28 AM
Have to disagree that it is on a par with the 45-70. Firing 300 grain bullets of decent alloy, the 40 caliber will give better penetration when loaded to the same velocity.+1, the .45-70 is a little better IMO. The .45-70 can be loaded to penetrate farther with heavier projectiles, but that is not to say that the .405Win is a bad cartridge in any way.

:)

Jim Watson
November 13, 2009, 12:26 PM
I vaguely recall reading of old time conversions of the Krag to .405 WCF even though DeHaas, Simmons, and Stebbins didn't mention it as feasible. People back then did not have the Internet to warn them against doing what they wanted to with an old gun, even if it meant treading on the safety margins.

However, I wonder if the advertised rifle IS an old time conversion. It appears vaguely modern to me, and of only medium workmanship. It looks to me like a senior project at one of the gunsmithing schools, done with NOS sights and a Krag action. The fleur de lis checkering pattern and glossy stock finish are later styling standards than when the old line Krag sporters were done.

The funky barrel contour looks like something done to demonstrate lathe and mill skills. The transitions from round to octagon to bigger octagon are not real smooth, and there is no attempt at all to transition from octagon to the receiver ring. Stamp marks are poor, probably done by hand with single letter stamps and no guide.

Stock inlets for the peep sight, loading gate, and the left side of the steel buttplate are a little ragged. The abrupt corner between wood and steel at the Mannlicher foreend cap is very awkward.

I'll give him a B on the caliber conversion; it would have been an A (assuming it works) but downgraded for doubtful caliber choice. C+ for the rest of the work.

StrawHat
November 13, 2009, 12:31 PM
Hey Maverick223,

I am saying the 405 is the better cartridge!

Maverick223
November 13, 2009, 02:55 PM
Hey Maverick223,

I am saying the 405 is the better cartridge!I know, I only agreed with the part where you said it wasn't on par. :D

Grizzly260
December 26, 2009, 02:53 PM
Quit arguing. My dad and I converted a 1898 Krag carbine to .405 Winchester. We've fired at least 1000 rounds ranging from 220 gn screamers at 2600 fps to 300 gn freight train loads at 2200. We have yet to have a problem with anything cracking. So unless you've watched a Krag blow up don't down talk one of the finest rifles ever devised.

Maverick223
December 26, 2009, 03:16 PM
No one has argued jack in over a month...well except for you, right now.

:)

If you enjoyed reading about "For those of you who think the Krag has a weak action..." here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!