Whichever way you go you really can't lose. The accuracy of the tikkas and sako are well documented. Aftermarket support and magazines are definitely easier to get for the tikkas. I own an A7 Tecomate in 270 wsm, which is very similar to the a7 big game from cabelas. It's the most accurate rifle I've ever owned and great to shoot. My dad has a tikka 695 in 7 mag and friends have t3 lites and superlites And all of them are great with no exceptions. My Tecomate is average weight with a zeiss conquest 3-9x40 in talley lightweights. It's not super light, but light enough and it fits me perfectly. The only thing I added was a stainless 85 bolt shroud and an extra magazine (as I was concerned parts would become unavailable if sako stopped importing them). You just have to decide which one you like and go get it. Good luck with your decision.
Craig
