I have tried H335, 2015, TAC, 4895, x-terminator and Varget with marginal inconsistent results. The 87 grain I have been using are the Hornady SP. I should probably weigh them to check the variance. Maybe its a bad lot. What bullet are you using? What barrel length? I should see if Sierra makes a non-varmit in the 87-90 range.

By the way mine also likes 2015 (25g) behind the 58 grain Zmax.

I have also been playing with the notion of ordering a 24 inch blackhole (another upper) to see if it would handle the heavier bullets better.