My first move would be a different powder or a different primer if your stuck on Retumbo. Powder change usually makes the largest impact, but I have seen primer swaps bring things together as well. My first move would be to grab two more powders, r22 and IMR7828 would be high on the list.

The 162AMAX shoots outstanding in my SFII 7RM over just about any powder/primer/brass combo you throw at it. It's done so-so with 140VLDs thus far(.5-.6moa). Just bought a box of the 168VLDs to try, but they'll have to really shine to beat the 162AMAX.

Good Luck

loder