In 1917, Brenneke created the 7×64mm by necking down his earlier 8×64 Brenneke case. This round preceded the 270 Winchester by 8 years. Working pressure is about 60,000 psi. Capacity is very similar to the 280 Remington but pressure is slightly lower than the modern SAAMI standard for the 280 or 7mm Express, so performance is theoretically a bit less. Any real difference is likely meaningless. The Brenneke cartridges are similar to most Mauser cartridges but used longer cases, sometimes higher pressure, and a slightly smaller case head (nominally 0.467-inch, compared to 0.470-inch), which is genuinely odd. Such a small difference in base diameter is of no practical importance so one must wonder why Brenneke chose to do this instead of opting for the common Mauser diameter or the 0.476-inch diameter of the 9.3×62mm, which predated the 8×64mm, from which Brenneke derived this round. I am reminded of a Robert Service line from, The Cremation of Sam McGee: There are strange things done in the midnight sunBy the men who moil for gold; … I would have to argue: There are strange things done in daylight sunBy the men who moil for ballistic advantage; … The 7×64mm has always had some popularity in Europe and for good reason. It will do anything the 270 Winchester will do or very nearly so. Chambering for the 7×64mm outside Europe has not been common for obvious reasons. These cases are hard to come by and most folks looking for a 7mm round of similar performance would logically opt for the 280 Remington. Those who own a 7×64 can use the best modern components to create loads of impressive performance. Loaded with the right bullet, it is certainly capable for hunting any non-dangerous big-game species worldwide.