Carcano M91 is still the best axis rifle, and has been since 2.15. It's actually the best rifle in the mod as far as I'm concerned, and is by far the one I can hit most accurately with. The M38 just has something 'wrong' with it in comparison, and I find the K98 (and other rifles that look like it) to be 'meh'.
As for allied rifles, I have a harder time choosing. I think they are much closer together in how effective I am with them (though the Springfield is by far the worst). I guess if pressed I'd say the No.4 was my favourite.
As for new rifles, well, I'm not at liberty to say. I have my desires though...
BTW, you should split the K98 into hooded and not hooded options. I know I find the non hooded one has the better ironsights.