Of course I just built a 243 LBC last year...lol
Dan
I built two and have no regrets. The new cartridge may be available as a factory load, but I'd still shoot only handloads no matter what. One benefit is that there will at least be some data available that is close to 6mm AR...but the new factory round will have less case capacity and therefore more conservative max loads. At least we'll have another clue to consider.
This, no regrets from me either, and I ordered another blank yesterday to build a third (a 12.5" this time, already have a 19" hunting setup and a 24" long range setup).
For a guy who handloads, the standard Grendel necked down to 6mm is easier than bumping the shoulder back too (and dealing with the resulting donut in the neck), and good Lapua brass is available for the Grendel, not so much for the ARC. For the handloader I think something like the 243 LBC is the better option, while still being able to take advantage of all the improvements that will come in magazines and more bullet options.
