T\C has a boat load of in-line M\L's on the market today. I just looked at their web site to see the Impact. Nice rifle with some nice options. I liked the fact that you could put on (if I read this right) spacers to adjust the lenght of pull. So, you could go from a kid, to a small frame Woman, to a "Big guy" all with the same rifle.
I have had a ProHunter for about 4 years and just last week I picked up my very first in-line barrel for it. The Endevor of course.
However, I don't think it will out shoot the Impact....or any other in-line (well....maybe some of the really low end "stuff").
But...I just shot it yesterday for the first time. I shot some 350gr. Hornady 358-Dia. using MMP sabots with 100gr and 120gr of Blackhorn. It kicked like a mule with the 120gr. and with either, didn't give me quality groups at 100 yards.
Then I switched to 240gr. Hornady XTP's in a T\C Sabot over 100gr of Blackhorn. Groupings were much better at 100 yards....3.5".....however, I did swab the barrel a few times, but I'm certian if I would have started with this, I could have gotton the groups even tighter.
I ran out of time....as the next time I want to "wire" in the scope at 100 yards, and then see how it groups at 200 yards.
BTW....the Blackhorn powder is as good as they say. Ten shots easy before you have to swab the barrel.
Good luck with your load development and your hunting!!