We received feedback on a few rifles built with our No.4 barrels. I would suggest contacting Bill Wylde or New Zealand Repeating Arms Company for exact details, but some info can be found here:

Prototype Criterion Lee Enfield Barrel Shooter Victorious In New Zealand National Match

The No.4 replacement barrels seem to be most popular with our dealers in Commonwealth countries (Australiaicon, Canadaicon, New Zealand, and the United Kingdomicon). We're getting occasional requests for barrels here in the US, but there are only a couple gunsmiths here who are familiar with the ins and outs of the Lee Enfield design.

Criterion is in the final stages of preparing a batch of No1 MkIII prototype barrels, but that project is temporarily on hold until the election season craziness dies down a bit.