I compared at 100 yards the groups with the stock yellow sabot, that came with the 290gr Barnes TMZ, and the harvester yellow crush rib sabots for boat tails. The ML was a CVA Accura V2 northwest, with a William rear peep and stock front fiber optic. The bullet was pushed with (2) 60gr magnum triple 7 pellets. The groups where comparable on four individual targets. The pressure to push bullet down the barrel was comparable, slightly less with the crush rib. I feel confident with my CVA.
I am in Port Orchard and have about 30 left in some want to test them in their ML. You are welcome to them.