Cheetah44,
You did not make it too clear if you can reload your own. If’n you can…..
Here is a really nice illustrated article copyrighted by Junior Doughty over at castbullets.com.
It’s a shotshell for the 44 Magnum but the principals can be adapted to the 500 S&W.
http://www.castbullet.com/reload/44shot.htm
Be aware that you will need to take responsibility for shot weight and adjustments to the powder charge when assembling a similar load in the 500S&W.
Maybe someone else can help in that area.
Be safe and enjoy your trip.