If this is a silly question, I apologize.
Not silly and glad you brought it up as I too have been looking into these. Saw one that was a real beauty, two weeks ago and when I asked the dealer what the diference was from the 452, he did not have a clue. Later I found out what it was. This one was the - .22lr/.17HMR and I'm more interested in the 22lr/.22WMR barrels. ......
Be Safe !!!