In case anyone else is wondering, the TRG has a metric pitch and the 595 has an imperial pitch. The metric pitch has enough meat that it can be turned down and rethreaded for the 595. Had to try it, hope it runs well.
Here's a shot of the 'improved' 595 with its countrymen. The TRG barrel seems to improve the balance and little as well as add about a pound and a half to the overall weight. Will be running moly'd Hornady 178's and 208's over the chrony later in the month to see how it performs. See what top speeds I can get with each and then tune backwards to an accurate load.