On the topic, I've never used or owned a pop up peep sight. But if accurate, look more than useful.

I wanted to acquire a CZ action with an integral pop up peep sight.

Years ago, I looked at a 6.5x54 MS and a 9.5x57 MS rifle at a local gun show. The 9.5 had a flip up peep sight I think. I was interested in both rifles but had just purchased anotherveifferent rifle and be or two MS's were outside my budget at the time.

Funny I told the seller I'd never heard of the 9.5x57, I'd heard about the 9.3x57. I didn't know it existed. He gave me a non amused flat look. Now I find my comment back then incredibly ignorant. The .375 Nitro Express or 9.5x57 is such an old cartridge. Over 115 years old. Its amazing how ones knowledge can change over time, especially through NitroExpress.com .

We might forget sometimes what the common shooters knowledge is on non "modern" commercial cartridges and rifles. The commercial market is always pushing the newest sh*t wannabe copied cartridge as if it's something new. The latest flat short cartridge, the latest crude more "must have" rifle.

Indeed I remember the 57mm casecas being promoted as "dead". The .243 Win having ascesdancy over the 6mm Rem. But if anything, the 7x57 is now more popular on the internet at least, than the ran out of puff 7mm/08. Thanks heavily to Rigby marketing,

These old vintage rifles with their useful flip up peeps are historical and in our modern times still very useful.