Me too, though mine's made from a much-modified M6 bayonet for the M14. We had a few excess in one stateside unit I was in when we traded our M14s in for M16A1s, and I *disposed* of them just like I was told to, since I was not given specifics of exactly where I dumped them.
But I hung onto one, and shortened the blade to a around 5½ inches, and it's now much, MUCH sharper than as- issued. And yep, I ground the muzzle ring off of mine too, though it was often carried when an M21 sniper's rifle that would accept an M14 bayonet was my usual companion. The latching mechinism is still in place on mine [it's a bit different from that of the M7 or M4 for the old M1 Carbine] so it could be so used if really necessary, but I can't really imagine ever doing so.
My original sheath was a modification of one of the USAF pilot's survival knife sheaths. At present I'm using a British L1A1 steel bayonet scabbard, with a nylon webbing cover and belt hanger, that works fine for me. The thing's more meant to be a utility knife than fighter [better handled by my khukuri, IMHO] and is more usually the one I loan out or carry in really nasty whether, or when having a spare along otherwise is a good idea. It's a bit heavy, and not quite either as light or as handy as the Schrade *Sharpfinger* that rides under my wrist in the elastic combo rig that carries a spare Browning GP magazine behind the top of my righthand wrist, but it'll do, it'll do.
I grew up literally in the deep woods, using axes, hatchets, and machetes pretty much daily. When I was about 5 I found an old meat cleaver and used it as a hatchet for some time. It actually made a pretty good one.
There is no edged tool as useful in the woods as a machete. The old U.S. Ontario are the best I have found although the tramontina (sp?) from Brazil are ok. I also have a Cold Steel khukri which is useful.
Any tool used for chopping or hacking, cuts better when sharpened with a file rather than honed. A buck saw is much easier to cut with than an axe, although an axe is still indispensible.
I have never done any formal training with knives or spears and don't really know much about it but a friend and I used to practice with a mop handle with a foam blade taped to it. I keep a Cold Steel spear near the door. I also keep several different swords around. I also think a machete would make a decent weapon.