anyone had any experience with, say, a Colt upper shooting 7.62x39? Like, for hunting (white tails), effective range & accuracy, decent ammo, etc?

There's no such thing as decent/accurate 7.62x39 ammo [BD]

Actually Neil I got some decent accuracy from my Oly 7.62x39 upper (not up to 5.56 capability - but as good or better than my lever action).  Reliability isn't as good as the 5.56 uppers, and high cap mags are a bitch to get (though 5 rnd hunting mags shouldn't be  a problem).

The problem is the cartridge is marginally effective - your best bet is using the Winchester 123 gr JSP (X76239) (recomendation courtesy of Dr Roberts's postings on another forum)

I've shot a number of deer with the 7.62X39 out of a Ruger Mini 30 and an SKS. All deer were taken within 60 yards. Two deer went down immediately and two ran away only to be killed later. The two that ran away were hit in the shoulder or upper front leg. The bullets showed evidence of breaking up on the bone and failing to penetrate the body cavity. The bullets used were Winchester soft point 123 grain factory ammo.

I recently bought a Model 1 Sales 7.62 upper for my AR. I sighted it in using Wolf's new 154 gr. soft point hunting ammo. I believe the heaver bullet will be better on whitetail than the 123 gr. My sighting in groups were about 3" at 50 yards without a bench rest. I didn't have much time to test these loads and only shot about 15 rounds.

Mags used were standard 20 round GI loaded with 5 rounds. This is the mag limit where I live and more than 6 rounds in the mag won't function anyway.

I did carry this rifle a couple times during the season but unfortunately, I didn't see any deer this year.

Shooting from a bench, I've shot 1.5" groups at 100 yards with my Colt R6830 Sporter Lightweight 7.62x39 using open sights and American Eagle ammunition.

When plinking soda cans up at a sandpit, my seat of the pants experience is that the 7.62x39 AR is just about as accuarate as 5.56x45.

thanks Gents, Good info, I thought I'd read that ballistics were about the same as .223, heaver bullet sounds like the way to go.  Most everyone I've heard from in Michigan wern't seeing as many deer as in the past.  Guys from western UP blame the wolfs...maybe the bow hunters are just realy successfull this year?  DNR claimed this years herd was the biggest yet. better luck next year..(for me also, no venison for freezer...but I'll keep my eye out for fresh road kill, I've had more success baging deer with cars than guns anyway...)

Load your own!