30-40 Brass from .303 British

[Grapeshot]

I work at an indoor range that allows rifles to be fired as long as the ammo is soft point, hollow point or frangible.  I found 16 PPU .303 British brass that someone left on the floor.  After looking at them and taking them homer I measured the head diameter was .001 smaller than the head diameter of my .30-40 Krag Brass.  So, just for kicks I ran them through my .30-40 Sizing die and set the shoulder back a bit.  I then loaded them with 11 grains of Trail Boss and a 200 grain cast round nose GC bullet.  They shot very well at 25 yards.  I am curious if anyone else ever tried this.

The reformed brass is a few thousandths shorter than the factory .30-40 brass.  But since I am on a very strict budget and on a fixed income, any method to get shootable brass is fair as far as I'm concerned. 

[Sir Charles deMouton-Black]

.303 Brit & .30-40 are fraternal twins.  I haven't had to convert one to the other, but I use them both to convert to .375 nitro Express.

I say you have nothing to lose.  Go for it!

[pony express]

Grapeshot, you're not the first. I was just reading recently(Not sure where, maybe on Gunboards) that during WW2, when reloading compomnents were even harder to come by than they are now, Surplus 30-40 was readily available. So they would break them down for components, to reload other calibers, and for .303 they would just trim the neck a bit and reload them.

Curious, though...30-40 brass has a bevel on the rim, that 303 doesn't. I never looked, but I guess since it worked without the bevel, then the Krag bolt face must not require the bevel.

[Major 2]

I have not needed to use one for the other either ,
however I discovered my Trail Boss load & the  Missouri Bullet Co.  .3115  High Tach coated Mosin Nagant bullet
works very well  for both  my Krag & SMLE.  That was after slugging the barrels and working up the TB load no need for GC's

https://missouribullet.com/results.php?pageNum_rsCWResults=2&category=6&secondary=36

#1 Russian-Grooveless
.312 Diameter
167 Grain FP - Grooveless
Brinell 20
For Mosin-Nagant
Hi-Tek 2-Extreme Coating

[Baltimore Ed]

I was given a bunch of 303 so when 30-40 was so hard to get i used the 303 in my krag scout and the hard to get  30-40 in my krag school rifle in order to keep from over working the brass. There is enough difference in the 2 rifles chambers that only full length sized brass works in both but I neck size the brass and then keep the brass segregated. I shoot less than 100 yds usually so I can?t see a difference downrange.

[RattlesnakeJack]

The difference between the rim diameters you measured is less than the SAAMI specs would suggest, at .005" ... note how close the other truly critical measurements are ... i.e. rim thickness and case body diameter just ahead of the rim:



In fact, these cartridges are so close dimensionally that when the Canadian and British Governments were acquiring Mills cartridge belts and bandoliers during the Second Anglo-Boer War (1899-1902) no modification whatsoever had to be made to the .30-40 cartridge loop specifications to work perfectly with .303 cartridges ...