Terry,
It is available from Miday online @ http://www.midwayusa.com/

on a side note did you buy this rifle new or build it? The reason I ask this is becouse iI have been contemplating rebarrelling my Marlin for this round and wanted to know of any problems encountered.

There was an excellent artical in this months "Handloader" magazine by Ken Waters where he was testing new powders on his round and it got me thinking about it. Doing what my wife calls "tore it up just so you could fix it again syndrome"