Real Gunbroker Men of Genius

[FredC]

Parashooter,
We have discussed this before does not hurt to do it again, thanks for the chart. Interesting that the 2 straight cases that I see 45/70 and 30 carbine show the same pressure for both styles.
303 and 308 with very similar powder capacities are 9 and 15 percent different.

With the Krag in the ad we do not know the actual bore size, if it happened to be .307 just a fuzz on the tight size the pressure could be a lot different than the 45/49 for 303 standard commercial ammo.

Proof rounds were mentioned at 70K. One proof pressure test in old riveted boilers made them stronger by shifting all the rivets till they were bearing evenly. Without the proof test only a couple might have had a load, when they failed the next tight ones would bear the load till they failed, pretty soon you get a catastrophic failure at what should be a safe pressure. I think the same principle applies to the proofing of the original Krags, the lug surfaces have slight angles on them, proofing would mush the surfaces slightly so that a higher percentage of those surfaces were bearing the load. One advantage the rifle has is normal wear would help the surfaces mate over time without proofing. Constant repeated overloads can not be good for a boiler or an rifle.

[psteinmayer]

As always... Para comes through with the good stuff. Many thanks Para!

This all boils down to misinformation, misunderstanding, and downright confusion. As FredC says, there are too many unknowns. Was it REALLY chambered for .303, or did some unsuspecting or uneducated shooter simply not know the difference (to the untrained eye, at first glance, one could easily mistake .303 for 30-40). Without actually speaking to the first guy sticking a .303 into it... and without actually measuring the chamber/barrel/receiver/etc., there are too many things left to chance!

[butlersrangers]

FWIW - If I understand the Springfield Armory procedures correctly, our barrels were proofed with special (sub-caliber) cartridges before they were rifled, out-side contours were turned, and several straightening operations were performed.

The barrels received this initial proofing before being "finished" & screwed into their ultimate Krag actions.

(The actions were likely proofed in a different process).

IIRC - A percentage of finished Krags, from a 'lot', underwent an additional proof firing.

[madsenshooter]

I've been given several varieties of .303 British ammo but I have no .303 British rifles. So most of the .303 got sized down in my tightest chambered Krag and it's now emergency Krag ammo, or it could still be used in .303 since headspace is on the rim. I'd use it in a sporter that has a .3105 groove diameter barrel if I needed to. Most is hunting ammo, but there's also some South African ball of WWII production.