7x57 Mauser UMC box question


Why is there a prominent very specific note about brass primers? What’s the importance?


Probably to indicate that the priming was NON-Mercuric ( Mercuric primers tended to use a Copper primer.)

Up to the time of the introduction of Brass Primers, all primers were Copper and mostly Mercuric (Before WW I)…so in the public mind,
Copper== Mercury Fulminate composition.

Other than that reasoning, I dopn’t have another.

Doc AV
AV Ballistics.


This box dates from approx. 1905, and brass primers had been in use since the 1870’s…UMC had a habit of touting the primers used in the cartridges, especially with smokeless loads, and especially when they came out with a new primer …