SR-77 (which is just S7 with the super Wauseon heat treatment) isn't anything near a stainless, but should have better stain resistance, by far, than 1095. 1095 (and the rest of the 10XX family) has really absolutely no stain resistance--it's a good blade material but it contains no chromium, which is the principle alloying element used to give steel corrosion resistance. In fact, the 10XX family is about as basic as blade steels get.
Swamp Rat's SR-101 (52100 ball bearing steel with, again, Wauseon's own special take on heat treatment) is again not a stainless by any stretch, but will also outstrip 1095 in this category, again as it contains some chromium.
5160 is a tough steel, and can hold an edge very well indeed if heat treated properly. It has more than enough carbon to be hardened up to the high 50s HRC. Again, everything is a tradeoff---keep in mind that while many steels will have an abrasion-resistance advantage over 5160, they gain that at the expense of other traits (i.e. ductility, edge strength, etc.), and all of them play into edge holding in different ways. If you're going to be cutting miles of cardboard or lots of coarse rope, abrasion resistance is key--but this type of cutting is not representative of what most use their knives for, and especially not big, thick knives like the ones being discussed here.
INFI is, in my experience, the best rust-resister of any of the steels mentioned here, with the exception of VG-10.
If you haven't, you really need to check out the Steel FAQ by Joe Talmadge here on BF, as an excellent overview of many popular blade steels.
http://www.bladeforums.com/forums/showthread.php?t=368828&highlight=12C27
You'll notice that almost nowhere in there does he compare steels with words like "better" or "best". Again, this is because absolutely every single one of them is making tradeoffs in its composition to favor some traits over others--if there were a single best, everybody would use it and nothing else.
To put it another way---If you made two identical blades, one out of 1084, the other out of S30V, both at HRC 60; and then set up a whole bunch of different cutting tasks (push cutting, slicing, impact cutting) in different environments (temperature variations, wet/dry climates) through a variety of cutting mediums (meat, rope, wood, bone), you would get vastly different results in terms of edge holding and general performance, and neither blade would be on top the whole time. They'd both have strengths and weaknesses, and which was "better" would depend on the intended application.
What is the rust resistance of sr-77? 1095 is so so from what i understand, INFI is fairly good, and what about the steel used in swamp rate knives?
There are a few bark river knives with blades as wide as .200" and Fallkniven knives come pretty close to being that thick too. Plus fallkniven uses VG-10
I just checked out ranger knives. At 1/4 inch thick you cant go wrong. 5160 doesnt seem like it will hold an edge real well but it is apparently a very very tough steel.
http://www.rangerknives.com/Knives/index.html
