Hi Gordy, welcome to Bladeforums!
The Bolt-action lock is a mechanism patented by Blackie Collins. It's not something that any manufacturer can simply start producing because they feel like it.
The liner-lock name is trademarked by Michael Walker, but not patented. It is probably the most common lock used today in high end folding knives. I personally prefer the older-style lockbacks to liner-locks, but they are not usually one-hand opening and closing knives. But I do own several liner-locks.
The McHenry and Williams Axis lock (Benchmade knives) is a superior lock mechanism. Frame-locks (such as Chris Reeve's Sebenza design) is reported to be a very good, strong lock system. I think lock strength is overemphasized by some, but not everyone feels the same way.
Some tactically oriented fixed blade fans have even claimed that 'thou shalt not fold thy knife' was one of the Commandments God forgot to write down for us modern folks with pockets.
Our own Jim March (community and political forum moderator) started an interesting recent thread which explored the need for high strength locking mechanisms in knives. Have a look:
An Open Letter to CRKT
Again, welcome to BFC. You are about to learn more about knives than you ever knew there was to learn.
Paracelsus
[This message has been edited by Paracelsus (edited 03-17-2001).]