Casper

Re the language barrier.

Take a photo and use photoshop (or whatever) to draw arrows where you want the measurements to be taken.

As they say, a Picture is worth a thousand words !!!

Also, can he take a pic of them next to a case we all know like 308 or 375 ?

Re what cart, what about one of the smaller BP cartridges ?
(I don't have access to my books ATM so it makes it hard to help).