chronograph my krag

[butlersrangers]

The weakest link when firing a chambered cartridge is the cartridge case itself. The U.S. Krag has a rimmed cartridge and headspaces on the cartidge rim. The case walls are very well supported in the Krag chamber. The action receiver has a single heat-treat which leaves the metal relatively hard and brittle. Fortunately, if a cartridge case fails in a Krag, the cartridge rim keeps the hot gases and pressure contained in the barrel, propelling the bullet, without damage. The Krag action bolt of course has one locking lug. This has limited .30-40 Government loadings to maximum pressures of 40-45,000 lbs per square inch. There are numerous loads, meeting all needs, that are safe in the Krag. Norwegian Krags, in 6.5x55mm, are considered to have better steel and metallurgy than U.S. Krags. However, they are also accepted as being a weaker action than the Swedish Mausers, with dual locking lugs, when it comes to reloading.
The 1903 Springfield uses the rimless .30-06 cartridge which headspaces on the case shoulder. The 1903 barrel-chamber does not fully support the cartridge case in the head area. A case failure allows hot gasses and high pressure to enter the action. The early (LOW #) 1903 actions are hard and brittle and more subject to burst or shatter in the event of a cartridge case failure. During WWI, a double heat-treat was instituted that left the steel more elastic so that receivers were less likely to fail.

[Stewart]

The 1903 Springfield failures are more complex than most people understand and I want to share a good article. It's a kind of forensic study with a lot of statistical facts rather than rumour and legend. The website is http://m1903.com/03rcvrfail/. The low serial number caution is a rule of thumb to ensure safety, and we all seem to need rules of thumb. Improvements in the heat treating process, including "double heat treating" improved quality control but they were implemented because inspectors found that the previous heat treating methods were sometimes done properly and sometimes not, at various times by various workers, with no reliable temperature measurements performed. And, like the Krag, ammunition problems also played a role. Most early 1903s did not fail, a few later 1903s did fail (also suggesting that ammunition was a factor). If the Krag's weakness is the single lug bolt design, the 1903's is the bolt face, which doesn't enclose the case head and relies to a much greater degree on cartridge case strength. The Krag bolt, aside from the single forward lug, has a bolt face very much like the later Remington push feed bolt design, which encases the cartridge head (rim). All rifles, action types and chamberings have pressure limitations, just as these two rifles do. I do not agree that Springfield Krags categorically have weak or improperly hardened metal. They should not be categorized with "low Springfields" as having suspect metal strength. Krags have been used a long time with factory ammo of relatively high pressures, with no known failures (that I know of). I'm continually reading about "weak actions" and using "low pressure loads" with Krags. I've also fallen into the trap of using other poster's terminology and will clarify now that not only is the action strong, I don't agree that the bolt is weak; that word implies a defect in metal strength and that assertion isn't supported by any evidence. It's just a design with limitations, like all others.

[Dick Hosmer]

Stewart,

Wait a second - this is turning into a discussion of angels and pinhead dancing.

Any 100+ year-old mechanical contraption that will repeatedly endure explosions generating up to 45000psi is not "weak", OK?

What I am saying is that - IMHO - the Krag design, if ranked impartially among all other bolt actions, would not be at, or near, the top of the list.

As you say, all designs have their limitations, but not all readers are as informed as yourself, and to imply that the Krag is a "strong" action is, I believe, potentially misleading to the novice.

Interestingly enough, I understand that one of the hardest (older/milsurp) actions to destroy is the 6.5 Japanese Arisaka.

[butlersrangers]

Dear mi-fordson: This thread started getting scary when .308 Winchester Data began appearing. Your query was about .30-40 cast bullet loads and increasing velocity for Deer Hunting.
My old 1967 Lyman Manual gave data for Cast Bullet #311290 with Gas Check (#2 Alloy) and 2400 powder: starting load 17 grains = vel. 1450 f.p.s. and Maximum Load 22 grains = vel. 1725 f.p.s.
Caution Caution - This is old data. (There are also other powders that achieve higher velocities with lower pressure). Always check current data and multiple sources. I have not loaded or used cast bullet loads in my Krags. But the Krag is famous as a fine cast bullet shooter. (It is very important to know the actual bore diameter of your Krag's barrel).
There is a Forum called "Cast Boolits". If you have not checked it out, there is a wealth of information there. Please always cross check loading data with multiple reliable sources. Enjoy your Krag and know its limits.

[Stewart]

Dick,
You're right and everybody has made some good points. It's never wrong to be cautious but unfamiliar/new/young people hear the overly cautious tales so much, they're scared to even fire these rifles. With the low numbered Springfields, there was a heat treating problem (a small percentage were tempered too hot) but the failures appear to have resulted from coupling a gun that was tempered too hot with substandard WWI mass production ammo. Every indication is that the ammo was more to blame and that modern quality ammunition would be perfectly safe in one of those rifles. The trouble is you don't know if a rifle had over-pressure WW1 rounds fired through it in the past, or how many or how many bad rounds it takes to make one fail. It sounds like most low-numbered Springfields were in service through the end of WWII without other incident. I've never believed or suggested that a Krag should be tested at pressure levels of a 30-06 or 308 but I regularly hear and read that the Krag action is 'weaker than the Lee-Enfield' for example. Have you looked at an L-E bolt? It's no different than a Krag; it has one lug forward, one at the rear and the handle lug. Interestingly, US ammo manufacturers load the 303 no higher than the 30-40 yet European manufacturers load them nearly to 308 velocities and don't lose a wink. I like 45 grains of W760 with a 180 gr. RN and I can find only one source to recommend quite so much for a Krag rifle. I could probably find a dozen that recommend not exceeding 42 grains with W760 or H414. That's a big difference. But, I worked up from 42 until I was satisfied that I could slightly exceed the Winchester recommended maximum which is 44.5 grains. I wouldn't necessarily be comfortable doing that with any Krag.
Mark

[mi-fordson]

I also am using an old manual from lyman (1969) i think and a old sierra from (1971) witch says the rifle used in testing was a krag. I was just looking to see if any of you veterans were using the same recipe and how will it worked for you and what kind of fps you were getting. I want to stay safe with this old rifle and still have a good quick kill on a deer. The more i handle this old rifles the more i sell my newer ones to buy more old rifles, it is amazing how our great country was being defended by these old things and i am very proud to have 2 of them to use and shoot. Thank you everyone for your input on this it it much appreciated.

Dear mi-fordson: This thread started getting scary when .308 Winchester Data began appearing. Your query was about .30-40 cast bullet loads and increasing velocity for Deer Hunting.
My old 1967 Lyman Manual gave data for Cast Bullet #311290 with Gas Check (#2 Alloy) and 2400 powder: starting load 17 grains = vel. 1450 f.p.s. and Maximum Load 22 grains = vel. 1725 f.p.s.
Caution Caution - This is old data. (There are also other powders that achieve higher velocities with lower pressure). Always check current data and multiple sources. I have not loaded or used cast bullet loads in my Krags. But the Krag is famous as a fine cast bullet shooter. (It is very important to know the actual bore diameter of your Krag's barrel).
There is a Forum called "Cast Boolits". If you have not checked it out, there is a wealth of information there. Please always cross check loading data with multiple reliable sources. Enjoy your Krag and know its limits.

[butlersrangers]

mi-fordson: you never indicated what charge weights of IM-4759 and #2400 you were using to get the velocities reported. I'm also curious to know the alloy and lube you used and if there were any problems with leading?

[mi-fordson]

2400 15 gr, 4759 16 gr LBT lube 20:1 alloy. So far everything is good have not shot any more sense the first post on this thread, i have not had a chance to load up any more yet. As far as accuracy i was too busy trying to keep from shooting the chronograph ;D i will work on that once i get a little faster with the round i will hunt with.


Nick

mi-fordson: you never indicated what charge weights of IM-4759 and #2400 you were using to get the velocities reported. I'm also curious to know the alloy and lube you used and if there were any problems with leading?

[knute]

I chronographed my Krag over the weekend. The barrel was replaced with a 1903 Springfield rifle many years before I purchased it and has a length of about 24". The Remington cartridges came out a little over 2200fps. The recipe I tried with 180 grain round nose yielded near identical stats. Printed material showed approximately 2400fps with the same barrel length. I'm going to leave it at that.

[Jaeger]

Didn't the original U.S. Krag fire a 220 grain, round nosed slug at about 1,975 fps?