I picked up about an acre of property that has been half-fast sorta cleared. It is fairly level and more thinned than cleared. The trees that were cut, left a couple dozen stumps 5-10 inch dia. and a foot high.

I want to cut them down to ground level with my last remaining chainsaw, a Husky 385XP so that I can at least rough mow.. The dilemma is working that close to the ground with a 28" chain. Does it make sense, or is it even possible to replace the chain/bar with one about 16"?

Shouldn't be hard at all to buy a 16 bar and chain.

This^ just be sure it's got the same thickness and chain same pitch as your sprocket.

You could roll them out with mini excavator if you rent one or cut them off and grindd them out renting a stump grinder.

Rent a stump grinder.

yup no issue at all
https://www.baileysonline.com/woodlandpro-16-timbermax-chainsaw-bar-60-drive-links-wptm-16-hu50.html

That thing will really zip with a 16' bar

If stumps are not green you may be able to pull them

Wanna be careful to not hit rocks with the chain, might consider spending a bit more and get a carbide chain. Cost will more than be made up saving all the down time spent re-sharpening the chain.

I'd also suggest that you get a skip-tooth chain. It will cut faster, and you can sharpen it faster.

I just scrape the dirt from around stump and if I have available water pressure wash where I will be cutting and let dry a day or two. Then when I start sawing I get the biggest squeeze bottle like dish soap or something comes in. Fill it up with used oil and as I saw I pour oil on bar and chain to keep it cool those stumps are hard. I have used water also but too much will get mud on chain and thats not good.

Put a 20” bar on it.

Stump grinders are nice and not as hard on your chainsaw.

Mini excavator would make short work of them.

Around here, when doing that kind of work we would be renting someone elses saw! :-)

Lol

Thought about it. Going to be as close to ground as possible. I need some numbers and assumptions to decide
Thought about it. Skip chain is better suited for longer bars.
Thought about it. If I am going short; the shorter the better. Less teeth waiting to dull themselves.

One more thing I thought about: chipper chain. I know nothing and am finding little on the internet.

The right tool for the job. Now all I need is the operator.
I might possibly need one. Gotta cut them down first.

Operating an mine excavator is fun and easy. You will be very rough at first but Within a day or two you will get very smooth. I put in 1200' of water line I was off from my grade deeper by a foot in places and bottom of trench wavy like rough sea the first several hundred feet. But when I got done it was flat and smooth within 1/4" the last 500'.