Need some dimensions- 30-40 Krag Improved/Ackley improved.

[FerricOxide]

A Freind bought a sporterized 1898 Krag a while back, I got to shoot it for the first time today and I noticed that the cases are quite different after firing them, They look like Ackly improved 30-30 in the shoulder area, steep shoulder, wider,etc . I was wondering if anyone could get me some dimensions for the AI variant so I could check the cartridges out and see if it's been re chambered or if it's just really worn. It shoots Remington factory krag really really well and the barrel is apparently original.

[Wayne Smith]

No way wear would produce that. It has been rechambered, the question is to what? You can google the 30-40 Krag AI to get SAMI dimensions, if there are any. I think the Sierra manual lists it, too, with dimensions.

[Rich/WIS]

Have a Ruger No 3 that was marked 30/40 AI, no idea who did it or when. Called C-H to order a FL dies set and they said send several fired cases as they had four different drawings for the AI chamber. Sent the cases and they did not match any of the four they had but had dies for 30/40 Lambert that were usable if I backed off .025 from the shell holder. If you reload for it you can try C-H or just neck size in a universal sizer die. After between eight and ten reloadings I have yet to need to FL size.

[Wayne Smith]

Well, I was wrong, Sierra does not have it. Ackley does not give dimensions in the two books I have of his. Donnelly & Townsley give the following:
Case Length - 2.24
Head Diameter - .457
Rim Diameter - .545
Neck Diameter - .338
Neck Length - .385
Shoulder length - .065
Body Angle (deg's/side) - .522
Case Capacity - CC' = 3.72
Loaded Length - 3.07
Rim Thickness - .063
Shoulder Diameter - .428
Length to Shoulder - 1.79
Shoulder Angle (deg's/side) -34.69
Case Capacity (gs water) - 57.35

Ackley does say that loads approaching the 300 Win Mag are used.

Hope this helps.

[Stephen Cohen]

Well, I was wrong, Sierra does not have it. Ackley does not give dimensions in the two books I have of his. Donnelly & Townsley give the following:
Case Length - 2.24
Head Diameter - .457
Rim Diameter - .545
Neck Diameter - .338
Neck Length - .385
Shoulder length - .065
Body Angle (deg's/side) - .522
Case Capacity - CC' = 3.72
Loaded Length - 3.07
Rim Thickness - .063
Shoulder Diameter - .428
Length to Shoulder - 1.79
Shoulder Angle (deg's/side) -34.69
Case Capacity (gs water) - 57.35

Ackley does say that loads approaching the 300 Win Mag are used.

Hope this helps.

I have only ever seen one Krag in the flesh, I was under the impression it was not a really strong action and was thinking loads approaching 300WM would be way to much for the Krag. No disrespect intended just worried about a fine piece of history. Regards Stephen

[FerricOxide]

Well, I was wrong, Sierra does not have it. Ackley does not give dimensions in the two books I have of his. Donnelly & Townsley give the following:
Case Length - 2.24
Head Diameter - .457
Rim Diameter - .545
Neck Diameter - .338
Neck Length - .385
Shoulder length - .065
Body Angle (deg's/side) - .522
Case Capacity - CC' = 3.72
Loaded Length - 3.07
Rim Thickness - .063
Shoulder Diameter - .428
Length to Shoulder - 1.79
Shoulder Angle (deg's/side) -34.69
Case Capacity (gs water) - 57.35

Ackley does say that loads approaching the 300 Win Mag are used.

Hope this helps.

Thanks.
In a ruger No1 you might be able to get away with that. With the krags single lug bolt and 121 year old metallurgy I wouldn't dare go that far.
"Due to the early metallurgy and single heat treatment (case hardening) of the action, the .30-40 cartridge operated at the relatively low maximum average pressure (MAP) of about 40,000 psi. It drove a 220 grain round nosed bullet at a leisurely muzzle velocity (MV) of 1,970 fps. with a muzzle energy (ME) of 1724 ft. lbs. from the Krag carbine and only slightly faster (2000 fps) from the long barreled rifle.

A later attempt to increase velocity and provide a flatter trajectory raised the MV to about 2,200 fps and the MAP to some 45,000 psi. However, the higher pressure caused bolt lugs to fracture, so the 45,000 psi round was quickly withdrawn from service only six months after its issuance, in October 1899.

Today, the .30-40 is loaded with a 180 grain spitzer bullet at a MV of 2430 fps and ME of 2360 ft. lbs. (Winchester and Remington figures), although the MAP remains 40,000 CUP. This increased performance is made possible by modern smokeless powders."

[Wayne Smith]

Sorry, I should have added that he was talking about it in stronger bolt actions, not in the Krag action. Cartridge capability, not rifle capability.