Ouch, cant believe some of the mis information on the .308 in here. It is a better caliber than most know, since there obviously hearing rumors on it passed through the grapevine.
I reload the heck out of .308 and I mean thousands, have 3500 Lapua brass I'm working on prepping now...
I used a propane buddy heater last year in Colorado at 11k plus ft, so yeah it worked just fine. It also has a carbon sensor on it for if it was to get carbon monoxide in your tent it will automatically go off. We didn't have any problems.