t mac 92: I have several Bucks, both old and new. You really can't go wrong either way with a 110.
However, if you do pick up an older one, make sure it has three dots or less. This "coding" will ensure that the knife is the old 440C, which takes and keeps a great edge. I have a couple of "two dots," and both are great blades.
The other two options are to: (1) Buy a Pete's Custom 110 (2) Buy a new Buck 110, and if you're not satisfied with the 420HC after using it a while, send the knife in to Buck for a blade swap (ATS-34 or BG-42). The price for the blade swap is reasonable, and it can make a difference in edge retention if you upgrade to a higher end steel.
Still, Buck gets a lot out of 420HC with their heat treat; you may be perfectly happy with this steel. I have 110s in 440C, 425M, 420HC, ATS-34, and BG-42. I really don't have any complaints about the steel in any of them.
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Here are some facts on Buck's 110 history and the steels that have gone into these knives. These dates and information are gathered from postings in the Buck forum, and include info from C.J. Buck and Joe Houser:
Buck used files on fixed blades up until 1961 when they switched to forgings of 440c. In 1968, they started using blanks (also in 440C) intead of forgings.
Prior to 1968, Buck knives were just stamped "Buck".
In approximately 1968 (perhaps 1967 on some models), Buck added the "U.S.A." to the tang stamp. These knives are also referred to as "two-liners" (BUCK + U.S.A.).
Then in late 1971, Buck began to add model numbers (eg. 110 or 112) to the stamping and these are called "three liners" (Buck + model number + U.S.A.)
The stamping identification marks began with dots on either side of the model number. Two dots were used in 1974-1980, three dots in 1980-1982. The three-dot knives were the last of the 440C steel blades.
In late 1982-83 the blades with four dots were the new 425M steel.
In 1986 the date stamping was introduced with symbols, the Buck website has details on the years and symbols used here:
http://www.buckknives.com/technical_making.php