So, I've just come across this article that asserts there is a difference in chamber dimensions between modern 9mm and original German FMJ RN dimension. The article also states there is at least one HK pistol he is aware of that uses this original chamber dim
https://www.buffalobore.com/index.php?l=product_list&c=212
Makes one wonder which model that is exactly, considering this may factor into the whole debate as to why USP's are rated for +P+ and others are not.
https://www.buffalobore.com/index.php?l=product_list&c=212
Makes one wonder which model that is exactly, considering this may factor into the whole debate as to why USP's are rated for +P+ and others are not.