doublegunshop.com - home Forums General Discussion Classic & Custom Single Barreled Sporting Rifles @ doublegunshop.com 375- 2 1/2" Nitro brass

Is this a difficult case to make, or is it available somewhere?

It's longer than the .303 British it's based on, otherwise you could just use those cases (2.22 vs. 2.5" case lengths).

QualCart doesn't list them but they may have expertise. I guess my next question is are there other, longer cases based on the .303 dimensions that might serve? Chuck Hawks says that cases can be made from .405 Winchester. (If you need .405 cases I have a crap ton of them.) I will say that there is some mojo and variability in the rim thickness on .405 cases causing headspace and action closure issues, and this might be a problem for your particular rifle - Sharps (they're commonly used for .40-70) and Winchester people seem to have issues and problems with this. Might have to file case rims down or build things up somehow, especially if yours is a British double based on who knows what original standard.

CH makes a full suite of dies. https://www.chtoolanddie.com/calibers/caliber?id=375Fla2.5

Lastly - https://beaksandbrass.com/product/375-nitro-2-1-2/ $6 each

I use 405 Win cases to make mine.
Not difficult at all.

If you use them in an en bloc clip Steyr, the back corner of the rim needs to be rounded off to feed reliably.

Bill,

I have some 375 2.5” cases. If you’re interested, let me know.

Ken

9.3x74R can be used, with more work than 405 cases. Some makes of 9.3 cases have smaller head diameter than others and may almost fit but require minor adjustment. length and maybe rim thickness will need adjustment.405 cases are not as plentiful as 9.3x74R cases in some areas.
Mike

Thanks for very helpful information. I'm deciding now if I want own a rifle in this caliber. KDGJ, your offer is most appreciated.

There is pressure tested loading information in Graeme Wright’s book, Shooting the British Double Rifle