What a logger uses is different with each company, and with each area they are using it in, and what time of tree's they'll be working with. One of the most popular anywhere is the MS660, its used everywhere from the PNW to the Midwest to the NE to Canada, just a great saw. For a little bit smaller timber stands, you'll find a lot of guys running 044/440's and 046/460's, or 372XP Huskys, occasionally a 575XP will be mixed in there. For big timber, the 3120XP seems to be a favorite, or even the 394/395's. I've seen guys running 385's or 390's, but not too often, they're kinda like 064's, every once in a while you'll see somebody running one, but I think they get teased about it back at the landing
.
Dawgs are usually Pro Safety or custom, and they are BIG
. Bars vary with the type of timber, and where you are, here in the NE, the bar is matched to the timber size, with a few inches extra, 25"-32" are most common, but smaller timber will run a 20". Handles also very a little, some feller's like a full or 3/4 wrap (I prefer them, although they ain't cheap), other guys like the standard 1/2 wrap. Chains are almost always Full Comp Square Chisel, it cuts super fast and super smooth, with the bigger bars its square chisel skiptooth. A lot of guys still run Round chisel chain, simply because its much easier to sharpen in the bush. Smack a stump vice in and throw in your bar, and you can sharpen a chain in 5-10 minutes, the same is possible with square cutters, it just takes a lot of practice and a steady hand to get them right. If its dirty timber, like some blow downs in gritty stuff, guys might run hardnose bars with semi-chisel chain, it all depends on what kind of loggin your doing.
BTW, I use my 044 for all the felling I do, if that can't handle it, I don't bother. With a 28" bar I could cut a 54" diameter tree (give 2 inches for the felling dawgs), that's huge. I have run a 32" bar on it on several occasions, but I have to switch to skiptooth for that, and its a lot less fun than the 25" with full comp, the 32" is just for 30" tree's, I don't double cut with it, it just takes too long, and I lose my patience, lol.