Any chance the sizing die or shell holder is deforming the rim? Could you chamber the brass again before resizing? If you can rechamber the fired case after firing but not after resizing I think your die or shell holder are to blame.

When I annealed my cases after forming them to 35 caliber I worked real hard not to anneal the shoulder. On a Krag annealing the shoulder is not so dangerous as on a bottle neck cartridge, but personally I do not think it is good practice.

'CoRifleman' - It is not unusual for two rifles in the same caliber to have differences in their chambers and for one with a tighter chamber to not accept a 'fired' cartridge case from the other.

This is usually resolved by full-length resizing.

I would suspect that possibly your F.L. Resizing Die is the culprit.

I just neck-size my brass and have the amazing good fortune that the neck-sized cases will inter-change between eight different Krags!

Easiest solution might be to just keep brass segregated for each of your Krags and try just neck-sizing. (Just loosen your F.L. Die one turn in the press).

If you want to experiment, try switching bolts and see if it makes a difference. (One of your Krags could have slightly tighter 'head-space').

(p.s. Is your 'cut-down' a model 1898 or a model 1896? There was a dimensional change made in the 1898 chambers).

FredC wrote on Jun 16^th, 2020 at 9:12pm:

1. The Krag cartridge is a "bottle neck" design.
2. I'm guessing the distinction you intended to make is between rimmed and rimless bottleneck cartridges.
3. It's standard practice for manufacturers to apply a final anneal to neck and shoulder of all new bottleneck cases. For commercial sale, the resultant color gradient is polished off afterwards - but for military contracts it is retained as evidence of the anneal. The unfired US military cartridge shown in the attached photo shows the annealed portion clearly extending about 1/4" past the shoulder - as is normal.

CoRifleman - The sizing difficulties you describe may be the result of inadequate lube and/or insufficient die adjustment. Many of the products currently marketed as case lube are pretty poor. Try plain, cheap castor oil, applied sparingly with fingers or lube pad and see if it helps. In addition, be sure to screw the sizer die at least 1/8 turn beyond simple contact with the shoulder to compensate for press flex under sizing stress. Look carefully where die and shellholder meet during actual sizing. If there's a visible gap as in second image below, that's press flex.

(The first image below shows sizing a .30-06 case down to 7.65x53, done easily in a single pass with castor oil lube.)

Typing while trying to think sometimes causes wrong things to come out, whoops. I have seen those colors past the shoulder. I wonder if they represent a full anneal on the shoulder as the material is heavier there and may not have been exposed to heat as long.
As Parashooter mentioned, I thought of lubrication. A reloader using premium pistol resizing dies with titanium nitride or carbide inserts does not need to use lubricant and might get caught with a problem on Krag cases.
On my sporter the chamber just in front of the rim was undersized. New cases would just barely load, rounds that had been resized with either 30/40 or 35/40 dies would chamber with difficulty and extract with extreme difficulty. Doubt that is the problem here, but something else to check if other things are not helping.

To rule out a bad die misshaping the case, I thought an experiment of firing a new round then opening an closing the bolt on the fired round may tell you something. If you can do that with not much difficulty then resizing makes it worse, the problem would seem to be the die.

From CoRifleMan's original description I was not sure if the problem was cases going back into the same Krag or interchanging between the sporter and rifle. The unusual effort of sizing relatively new cases seemed to indicate a problem other that need for annealing. Maybe I misunderstood and these were cases loaded 20 times.

Annealing is usually recommended to prevent case neck splitting and best applied a couple of reloadings before the necks do start splitting. Maybe more often for target shooters to maintain a consistent neck tension.

Maybe I am thinking while typing again and all this is off again?

'CoRifleman' - I was not saying anything was defective.

Things are built to different tolerances: Reloading Dies, cartridge brass, rifle chambers, and rifle bolts.

Rifles are subject to differences in the amount of use and wear they receive.

The manufacturer standards for .30-40 Dies were established about 30 years after Springfield Armory built its last Krag!

I imagine there are differences in the dimensions used by each Die Manufacturer.
There will be differences in each set of .30-40 Dies made by the same manufacturer.

A rifle cartridge Die Maker has to make a product to accommodate chambers made by Springfield Armory, Remington, Winchester, Harry Pope, and Ruger.

A cartridge manufacturer has to size their brass to chamber in just about any .30-40 chamber ever made.

Brass gets "work hardened" and more brittle with being reformed and with age. Annealing the case-neck and shoulder restores 'pliability'.

FWIW - If you have a Die that is toward the maximum in dimensions and a rifle chamber/bolt combination that is at the minimum of dimensions, you may have a problem with reformed brass, (that was fired in a different gun with a more 'liberal' chamber), fitting the tighter or shorter chamber.
Trying a different set of Dies or a slightly different dimensioned Bolt may correct the 'clash of tolerances'.

There were minor changes made by Springfield Armory to the dimensions of U.S. Krag chambers in 1899. There was a change of .002 or .003 inches in head diameter and length from breech-face to shoulder. (Information attached).

Currently, I only have to separate brass for one of my Krags, a model 1896 rifle with a chamber that allows more expansion of the cartridge-case body.

My other Krags get fed reloads that are partially 'neck-sized' with a LEE - Collet Die for 7.5X55mm Swiss, no lube necessary. Once in a while, I may close the Bolt on a reloaded round with slight resistance, but, no problem.

I'm lazy and it ain't rapid-fire at Camp Perry!

Note - Per Mallory - The change in chamber dimensions occurred at around serial number 213,000.

If Mallory was correct, Model 1898 Krags (below that number), and model 1896 & model 1892 Krags, may have more liberally dimension-ed chambers.

FWIW - (Re-barreled Krags can totally different. I use to have a model 1898 'cut-down', that was put together by Sedgley. The replacement barrel was made from a (1905 dated) 1903 Springfield barrel. The tight chamber would accept factory ammo and my F.L. resized cases. It would not accept a 'fired case' from any of my other Krags).

FredC: I have separated the drawings to make it clearer: Old vs. New.

The Krag chamber was never recessed for the rim. The old drawing could give that impression, so I have eliminated the confusing shade areas.

Good eye on the .030" dimensional difference! Old Ordnance Dept. Mistake?

I suspect, the difference may actually be .003".