Clownbuster
WKR
There have been some changes to the first released reamer. Clickers were developing in fired brass past the .200" line of the chamber, so they widened the reamer .002" to solve the problem.I ordered the dies back in August from UM, I don't think ordering them from Whidden directly would get them to me faster. However, I've pretty much decided to bail on the 6UM and go 6 SAUM.
I started the project trying to get a DTAC going over 3200 since I couldn't get there in my .243 AI. Looks like the 6 SAUM will easily do what I want and I can use the same dies with a different neck bushing if I decide to do another SAUM down the road (I think 25 SAUM would be fun and I already have a 6.5).
As far as brass I thought the 6 UM brass was just a 6.5 SAUM necked down to 6mm, I'd bet that's the case as that's a relatively simple change to the process compared to a whole new set of case dimensions. A run through the sizing die would fix it anyway.
The whole idea of the 6UM was great when it first came out, buy the reamer (which was not proprietary at first) and take it to your local gunsmith and have them cut a barrel. Now that it's all proprietary it's a tougher proposition.