Krag Collectors Association Forum

Doubly Reincarnated wrote: ↑Thu Dec 01, 2022 7:38 pm Cracked bolts are nothing new. Cracked bolts and increased barrel fouling are what led to the abandonment of the 2200 fps load when the Krag was still in service. There must have been hundreds of them over the years.

Sorry Br, I read the top sentence and missed the next one. Whoops!

It is interesting that for as famous a Krag 'cracked locking-lug' is, few of us actually have such a bolt or have personally seen one.

The picture of the broken bolt looks like the pictures that Hatcher had of ’03 receivers that were “burned” in the single heat treat receivers. From his description of Springfield’s process for heat treating it was very sloppy compared to the way it was done later, pretty much a by eyeball and seat of the pants.
I wonder what percent of the bolts that broke were ”burned”?

Doubly Reincarnated wrote: ↑Thu Dec 01, 2022 7:38 pm Cracked bolts are nothing new. Cracked bolts and increased barrel fouling are what led to the abandonment of the 2200 fps load when the Krag was still in service. There must have been hundreds of them over the years.

There was an article in Gun Digest about the use of cupri-nickel jacketed bullets in 03 Springfields. It led them to dipping every bullet in MobilLube when target shooting to stop the fouling. The nickel fouling was no problem at standard 30/40 velocities. From your comment it looks like 2200 feet per second is the velocity that things started getting bad. That fouling was probably closing up the bores leading to excessive pressures. Evidently the fouling was a bear to get out, ordinary cleaning would not do anything.
The article had photos of Springfields that blew up from the Mobil-Lube getting on the brass case and chamber leading to excessive bolt thrust. The problem went away when they discovered the jacketing materials still used today.

The stuff about cupro-nickel bullets and difficult-to-remove fouling was known and written about more than 120 years ago. There's an obscure (and bloody marvelous) 3-volume set of books, "History of Modern U.S. Military Small Arms Ammunition", by Frank Hackley, William Woodin, and Eugene Scranton, covering all issue & experimental cartridges from 1880 through Viet Nam.

They write (Vol 1, p. 82) "During the 1898 to 1900 period, the velocity of service ball ammunition was experimentally raised from 2,000 to 2,200 f.s. By March, 1900, due to increased bore wear and stripping of bullet jackets, it was reduced to 2,000 f.s." Their citation is NA 156, 31357.

What in 1900 was "stripping of bullet jackets" I think we call metal fouling. The cupro-nickel jackets proved to be a problem at 2,200 f.s., so with crystal clear military thinking, they used CuNi jackets for the 220-grain .30-03 bullets at 2,200 f.s., and then for the .30-06 and 150-grain bullets until the early 1920s. The "working cure" in those days was frequent barrel cleaning with "strong" (or 28 %) ammonia. Sharpe cautioned users of this stuff not to leave it in your rifle barrel for more than 20 minutes and to rinse it out with very hot water.

DoublyR,
I was unaware of the problem till I read the article in Gun Digest. Your comments that the issue started back in the Krag days was new to me. The KCA is a source of a lot of good knowledge.
Curious if the Germans had the issue with their 7mm and 8mm Mausers? How about the Brits with the 303? If they did not, why did it take the US and our commercial ammo makers so long to solve the problem?