Quote:

---

The maximum rim dimensions for any commercial loads to be sold in Europe are prescribed by the CIP. According to the CIP tables the rims of the .5x53R Mannlicher are 1.25 mm = .049" max thickness and 13.4mm = .528" dameter, while the .303 British rims are 1.63 mm = .064" thick and 13.72 mm = .540" wide. I never had any problems with the larger rim thickness of reformed .303 brass in 3 Rifles, but I had to reduce the rim diameter slightly to work in my Gibbs Mannlicher. Besides, the cases with the reduced rim diameters move far better through the Dutch and Portuguese en-bloc clips I have.

---

Kuduae, thanks for the informed input.
This is interesting in that any of the vintage Brit rifles in the 6.5x53R/.256 Mannlicher that I have examined all have a rim seat or headspace of ~.060”. Same of course for ~8mm Rimmed, as well as .375 2 1/2” NE, and .303 British
I wonder if rims were thicker prior to CIP standardization?
Old vintage ammo seems to be of thicker rim as well.

- Mike

Buffalo re-formed and trimmed on the left, Bertram 6.5x53R on the right