Copy and Paste from their website
Predator® and TAC Differences
There are very few differences between the TAC and the Predator actions. Here they are:
The bottom cutout on repeaters
The Predator short and long, 308 and magnum boltfaces have an extended loading box cutout. The cut is 0.130 longer than a standard Remington. It will take Wyatt's Outdoor or HS Precision extended boxes.
The 223 boltface Predator, TAC30 and TAC300 series actions have the standard cutout and will take a Remington box as is.
Scope holes
The Predator XP, short and long action has 6 - 48 TPI screw holes.
All TAC actions and the Predator Xtreme have 8 - 40 TPI screw holes.
Bolt Knob, all threaded on
Predator and Predator Xtreme have small teardrop.
All TAC actions have larger tactical knob anodized black.
Finish Color
Predator and Predator Xtreme are matte finished stainless
All TAC actions have black oxide finished stainless.
TAC338 and Predator Xtreme
Same action except color and name. Both have universal cutout on bottom for either AI magazine or Weatherby box