The only difference between a 452 American and a 453 American is the trigger. The 452 Varmint and 453 Varmint shares the same difference in trigger, but also has a difference in stock mounting. The 452 has one action screw, and one screw in a lug that's attached to the barrel. The 453 has two action screws, with nothing in the barrel. The trigger is well worth the difference in cost, as it has adjustments for pull weight, pre-travel (creep), and post-travel, plus the single set trigger function. The 452's trigger only has one adjustment, for pull weight. If you care about pre-travel, you'll have to do some modification or replacement, and nothing reasonable can be done about post-travel.