Strength of Krag actions

[grouch]

P.O.Ackley tested a number of military bolt actions to destruction. Does anyone know where to find the results, and specifically how the Krag really did?
Grouch

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[Bill H]

His handbooks have been re-printed, and are available. Try the book dealers on the internet.

He did not find the Krag as strong as the later actions, but his comment was that it was quite strong. Note that his method was to load hotter and hotter loads, and some of the failure modes do not respond to this.

With a Krag you run the same risk as with a low number 03, the heat treatment left the metal brittle, but not to the extent of the 03s which were overheated during the forging process.

[MIL rifle1]

How safe are old Krags to shoot with factory loads? I love shooting mine, but wondered just how safe they are.Any opinions would be appreciated. Thanks, Paul.

[Art]

your Krag should be perfectly safe with factory loads assuming your rifle is in good condition. U.S. factory loads are made up with any strength issues of the rifle they're going to be fired in in mind.

[us019255]

Warning: I can not verify this post, as Fred Telke has been dead for ~30 years. It is true to the best of my knowledge.

My father-in-law shot a Krag competitively during the '20's to 30's. He experienced a cracked bolt lug. As a tool maker he had access to all the tools, and heat treating equipment needed. He had taken some college level metallurgy classes so he took the bolt to the prof. The professor concluded that the bolt was indeed brittle, but that one made of a different alloy, and heat treated properly would be much stronger. Fred made one and used it in competition for many years.

Unfortunately, after he married in 1939 the rifle was sold as he stopped service rifle competition.

[Oldyoti]

Warning: I can not verify this post, as Fred Telke has been dead for ~30 years. It is true to the best of my knowledge.

My father-in-law shot a Krag competitively during the '20's to 30's. He experienced a cracked bolt lug. As a tool maker he had access to all the tools, and heat treating equipment needed. He had taken some college level metallurgy classes so he took the bolt to the prof. The professor concluded that the bolt was indeed brittle, but that one made of a different alloy, and heat treated properly would be much stronger. Fred made one and used it in competition for many years.

Unfortunately, after he married in 1939 the rifle was sold as he stopped service rifle competition.

This is an interesting tid-bit you've posted. Understanding the botched metallurgy of many if not all of the US Krag actions to some degree, coupled with the brittle bolt's single forward locking lug, backed up only by a non-bearing bolt-rib safety lug, it's obvious the reason for limiting these rifles to mid pressures at most.

By contrast there is the Norwegian Krag, which to my understanding was produced with correct metallurgy and processes, then it was case hardened. Work was applied to the bolt as well making the bolt-rib a true second locking lug, bearing against the action's rear ring through careful fitting at the factory. Though not as strong as most dual forward lug actions, the "Norge" Krag is quite a bit stronger than the US Krag...

If manufactured today with modern alloys, with both lugs working to lock the action, how strong would this smoothest of bolt actions become... any thoughts?

[andiarisaka]

Some Krags, like the later Springfields, were overcooked and made brittle, I have on in the 13000 serial range that is cracked in two places, one right behind the locking lug recess, the other further back in the bottom of the receiver. This receiver is very hard, won't take a file, and has a distinctive high pitched ring to it when struck. Since the case is fully inside the barrel ring, the Krags don't fail like the later Springfields though. In fact I had shot the cracked one a few times before noticing the cracks and retiring it.

[Jim K]

The Krags did potentially have the same metallurgical problems as the "low number" M1903s, but they also had a serious design flaw. Both the earlier Danish Krag and the later Norwegian Krag were set up so the guide rib acted as a second locking lug. So, even though the lugs were not symetrical, those rifles had two substantial lugs and both are quite strong.*

But when the U.S. adopted the Krag, they (not Krag) decided to set it up so there was only one true locking lug and the guide would act as a safety lug. The safety lug would not bear and would touch the receiver if, and only if, the front lug failed. I have never been able to learn why that decision was made, but it severely reduced the strength of the action and put all the strain on one relatively small lug.

Krag locking lugs broke frequently throughout its service life.# At one point, the Army tried to increase bullet velocity to 2200 fps, and even issued sights graduated for that velocity. But so many bolts broke with the new round that it was hastily withdrawn from service and the sights replaced with the old ones.

*A company called Mauser had a patent on dual front locking lugs as part of the bolt body, which is why Krag couldn't go that route.

#Which is why there was a good supply of new Krag bolts up to recent times.

Jim

[jon_norstog]

The Norwegian and Danish krags supposedly used the bolt rib as a second locking lug. I've never shot one, but I've seen a few. Jim Bedaux in Albuquerque had a real nice one in 6.5x55, sporterized with a Bedeaux custom stock. The Danish Krags were chambered for a really hot 8mm rimmed cartridge, definitely a step up from the .30 Army.

As for the US Krags, they will take a fairly strong load without coming apart and IMHO make a way better big game rifle than a .30-30.

jn

[Jim K]

I don't know about a "way better"; the .30-40 case will hold more powder, but factory loads are not impressive and the factor we are discussing limits the .30-40 to pressures in the 40-45k cup range. If I were limited to loads in that general range, I would probably choose based on which type of rifle I preferred rather than the cartridges.

One interesting thing, and I will gladly stand corrected if I am wrong, but I don't believe any commercial rifle was produced in .30-40 except the Winchester 1895. Most other military calibers have automatically created a large sporting rifle following (think .45-70, .30-'06, .308, and .223), but I can't recall any other commercial sporter (not a custom rifle) regularly chambered for the .30-40.

Jim