Welcome to the forum!

I made some training rounds by loading brass I no longer used (very old US .30 brass I wouldn't trust live).  I removed the primers and filled the primer pocket with soft melt glue (gives the firing pin something to strike without risk of damage).  I then loaded with 220 gr RN bullets and painted the case necks black with ink to indicate that these are inert.  This is what I use for both practice, and testing for the chargers I make. 

If you're interested in shooting in Vintage Rifle Matches, there are several around the country, as well as The National Matches at Camp Perry (I shoot there every year).  There are several of us who would be more than happy to help you get started.