Jeff,
From their site....
"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"