Head stamp question

[Amon458]

Ive heard people talk about Officials looking at your head stamp to make sure it matches your gun but I am working on geting a wildcat that is made from 50BMG brass so there is no caliber stamped on the brass would this cause problems with taking this rifle to other countries?

 

[drew416]

Don't know about American Customs officers, but on my two African Safaris, Australian Customs officers have inspected my empty brass and remaining live ammo to ensure headstamp matches paperwork and what is stamped on the firearm on my return into my country.

All this and I am a lovable looking guy?