I would first say that I agree with Cliff. The A2 in my Mountaineer seems to hold up quite well to general use, especially considering the previous owner had sanded/polished all the coating off the blade forward of the handle and guard. It actually looks nice, and I haven't had any problems with corrosion, however, I haven't used it in severe or adverse conditions. I added a piece of shrink tubing (another recommendation I got was small cross-section inner tube) around the handle for a bit of increased comfort, so temperature changes have not been a consideration for me.
I'm very impressed with the BG-42 as used in Sebenzas, so much so, that when I ordered my TKK from Trace Rinaldi, I specified BG for the steel. Both my small Sebenza and TKK have seen alot of use, and are holding up exceptionally. I've become a big fan of BG-42 as a result of my experience with these two knives.
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Don LeHue
The pen is mightier than the sword...outside of arm's reach. Modify radius accordingly for rifle.