A nice long range rifle with a sad life.

[Rapidrob]

In 1975 I was stationed in San Diego. We had finished a cruse and I had lots of free "down time" and was working part time at a local gun shop. The owner had just returned from Mexico where that country had dissolved citizen gun rights and returned with a case of Krag rifles.
Most were in very good shape with bright bores. I got one for 75 bucks and grabbed a hand full of original cartridges and went to the range.
I had been collecting US military firearms for tens yeas by then and was really looking for a nice shooting rifle.
I loaded up the rifle and pulled the trigger. The bullet missed the target by several yards and I noticed "silver confetti' fluttering to the ground. What the heck?
I removed the cartridge which looked fine and the bolt. The rifling was gone! As in blown out of the barrel. The Mexican military had fired mercury primed ammo out of the rifle and never really cleaned them before putting them in storage. The rifling had amalgamated and had become soft/brittle over the decades.
I told the owner what had happened to the rifle and he checked the others as well. Some were worse,others were a little better.
I got 25 bucks back as I wanted to keep the rifle as a type in my collection. I'd find a new barrel and replace it.
That took 40 years! All I ever found was Bubba'd barrels or the wrong year type barrel. I wanted to find an original barrel.
In 2016 I did. It was like new on the inside with a nice patina on the outside that matched the rest of the rifle and it was the same year! Wahoo.
I had my local gunsmith mount the barrel. I went to the range and with 220 grain RNFB FMJ's the rifle shot very well at 100 yards. I set my target to 500 yards and had no problem using the peep sight and hitting the target. The rifle has shot very well at 800 yards as well.
But, there is a problem. The chamber is long. Head space is within "field" but the fired cases stretch in front of the web. They fail if reloaded. Crap. Oh well.

[Rapidrob]

500 yard target and a couple more photos.
I run NM Military Rifle Pistol Shooters and we shoot out to 1,000 yards with old surplus firearms. Forgotten Weapons on Youtube did an episode on us.

[butlersrangers]

'Rapidrob' - Welcome to the KCA Forum!

You can purchase a 'New-Old Stock' model 1898 Bolt from 'Movieman 630' (on ebay), aka - 'Grandpa's Gun Parts' (in KCA Classifieds), for $55. This would likely reduce your head-space. But, that might not be the problem.

With the .30-40 being a rimmed cartridge, 'Head-Space' on a U. S. Krag is measured from the bolt-face to the rear face of the barrel, where the cartridge rim stops.
IIRC - This runs about .064" minimum ('Go') to .074" ('Field').

Many Krag Shooters 'partially' Neck-Size their fired cases and 'excessive' Head-Space is never an issue.

Other excessive dimensions can cause case problems:

1. Excessive chamber diameter (which would leave a case poorly supported and likely to expand and split length-wise).

2. Overly long chamber (which can allow the case-shoulder to move excessively forward, causing case-head separations).

Photos of some of your fired cases, might better reveal the problem and facilitate solutions.

FWIW - I once had a (.303 cal.) Short Magazine Lee-Enfield - Mark III. Its 'brand new' barrel produced complete head-separations, with new commercial Brass, after one reloading.
The rifle had been 'Factory Thorough Repaired' by B.S.A. in 1953 and was like new.
But, the Chamber dimensions were 'sloppy' and not intended for reloading! The case shoulder was blown forward and the stretch thinned the brass above the case 'Web'.
(Even Neck-Sizing did not help. I have never had this occur with a Krag).

It is probably unknown, what your 'new' barrel has been subjected to?
A 'chamber-cast' would reveal if dimensions are 'out of whack'.

[Rapidrob]

I did a search here several times to find the fellow with the Krag bolts. Can you provide a direct ling to him?
Thanks

[FredC]

If a new bolt fixes it everything is good. If not a suggestion I have seen here on this forum may work.
Putting a wrap or two of dental floss ahead of the rim will hold the case back against the bolt face on the first firing, then neck sizing only after that as suggested by Butlersrangers. Your future reloads will actually be head spacing off the front shoulder like a rimless cartridge afterwards.

[Culpeper]

Welcome to the forum!

Here is a solution if all else fails. And you don't have to wait forty years.

CMP E-Store

https://estore.thecmp.org/Catalog/Item/065CRI/3040R

[butlersrangers]

'Rapidrob' - A new bolt may be the fix, but, if the barrel chamber is 'messed up', it won't fix that.

A chamber cast may be warranted.

Granpa's Gun Parts can be reached by searching 'Classifieds' at the top of the Board Index Page. There is a Thread, (so labeled). 'Culpepers' response in that thread has a Link, that goes right to 'Granpa's Gun Parts'.

The proprietor of G.G.P. is David Stewart - P.O. Box 92 - Dublin, PA. - 18917 - (mark: Attn: GGP).

Email is: DBS3@GRANPASGUNPARTS.com

(David is the grandson of the late-Joe DeChristopher, who was a noted U.S. Military parts dealer and authority).

David carries on the business. On ebay, he sells Krag parts, as Movieman630, with free shipping.

Try this:

http://www.granpasgunparts.com/krag-springfield

[Rapidrob]

I found Culpepers. Thank you.
I tried a new load today to see if perhaps the powder/brass was a problem as headspace is not excessive.
I loaded up IMR-7383 under a 200 grain bullet. I lightly lubed the brass to allow the brass to form to the chamber walls. The fired case is identical to a new virgin case other than the shoulder angle. No case stretching.
I'm beginning to think the brass is at fault.
I reloaded the same case five times ( neck sizing only) with no splits.
This powder is slower burning than IMR-4350 and IMR-4895. This may be the powder to use to save the brass.
I will try the load tomorrow at 385 meters and see how it holds up and how accurate it may be. They are calling for winds up to 40 mph.

[butlersrangers]

What powder charges were you using with the reloads that were stretching brass and "causing cases to fail"? (Full head separations)?

IMR-4895 is too fast of a propellant to use in .30-40 rounds with 220 grain projectiles.

Maximum loads for IMR-4350 and 220 grain bullets is around 40 grains.

IMHO lubricating cartridge cases is courting disaster and likely ups pressures unpredictably.

I went back and looked at your first post. What "RNFB", Full Metal Jacketed, 220 grain bullet were you using?

[FredC]

With lubed cases I would worry more about bolt thrust than pressure. Back in the early 03 Springfield days lubing the bullets was necessary to prevent the stripping of the copper nickel alloy bullets from lining the bore. Sloppy application of the Mobil lube would coat the chambers and cause bolt thrust to destroy the rifle and sometimes injure the shooter.
Be sure to wipe the chamber dry before doing any more shooting of full power loads.
Be careful of forming the brass with reduced loads as some reduced loads can cause a process called detonation. I think pistol powders are preferred for reduced loads. I would try a recommended load from a manual to be safe with reduced loads.