Interesting barrel guide

[Blueheeler 0]

This has been on ebay for a while, but I just noticed the markings, 7.65x53 and 46, which I take to mean its for a 7.65 argentine barrel and was made in 1946. Anyone ever see a 7.65 arg. JSAR barrel? 

 

I do know the argies produced a single prototype M1941 copy in 7.65x53 in the 50s. 

[camstuff 0]

I’ve never seen one. It’s an interesting piece though.