Looking for a 1/2x28 Radial brake for 6.5mm. Lightweight is optimal. Will be going on a Howa Superlite. The Christensen Mesa brakes would be about the right size for a reference.
APA has the answer (gen 3 micro bastard) on sale.
A weatherby accubrake ST (vanguard #1 20”/#2 26”) should be a good fit if you want radial.
I put a meraki machine M1 on my on my superlite and really like it.