I had cut down my 30 year old 20 degree + sleeping bag for a cowl blanket, after pricing a ready made cowl blanket for the S-7S ($350.00). That left me with a 5 year old 20+ bag, and as I am a believer in the layer system (one bag in side or on top the other gives multiple options as to heat retention, all the way from 30+ degrees to zero), I had already ordered a brand new 20 + bag from REI (thinking I could put it into the older 20+ bag), when my sometime employee Frank (interesting "kid", in the first Gulf War, he was in command of a Bradley that took a hit from friendly fire, and then was swarmed by nearby Iraq National Guard "Elite" troops, he singlehandingly held them off, and took quite a lot of them OUT, (think Rambo, no kidding), and saved his remaining crewmates, word is he may be in contention for the Medal of Honor, I have NEVER asked him about any of this, this is just what I have picked up from second hand sources, like my 3 tour Viet Nam era Marine sniper older brother, he doesn't talk about it, ever) told me about a deal at the local Pocatello gun shop, (Doc's Gun Barn ph # 208-233-3912). They were selling a military issue extreme weather sleeping bag "system" for $100.00! Upon further research, I found he had got the local hero discount, and I don't mean that sarcastically. For the rest of us they are priced at $125.00, brand new/never used, and complete with a super nice heavy duty stuff/compressor sack.

9lbs 6oz. it consists of a light weight bag, good for 30+, that snaps into a heavier bag (good for -10), that snaps into a Gortex like bivy sack. All of these can be used alone or 2 at a time or all at once. All at the same time and all zipped up the rating is -50! Super high quality, all with separate zippers, and the great military labeling ("bag, sleeping"), that ensures it is the real deal. I have canceled my order to REI (they were backordered anyway), taken out the 9 lb+ tent I had intended to use with the dual 20+ bags (3 or 4 lbs each) and now, for my winter "fun", I will just carry this.

If this sounds like a good deal, call Doc's, they only have 2 left, they are not really any kind of an internet outfit, just a local gun/sporting goods shop, but you may be able to talk them into taking it down to the UPS package outfit and still be into for way less then 200 bucks. Mention you heard about it from a friend of Franks, can't hurt.
Oh yeah, the outer bivy sack, made of a Gore tex type material is Camo, good for hiding from Life Flight, but thats another story!

I've spent a decent amount of time sleeping in that system (courtesy of uncle sam) and it is pretty good, but I wouldn't recommend it down to -50. About the coolest I've used it and felt reasonably comfortable was down to single digits. The ability to mix and match the layers is pretty nice and the bivvy sack gore-Tex performs pretty well - no doubt a good package to toss in the back of the plane.

We carry that in in our kits on the Twin Otters, I've broke them out flying through Raton pass in the dead of winter up high because it was so cold in the back of the plane and they are quite comfy.

Vick wrote:I've spent a decent amount of time sleeping in that system (courtesy of uncle sam) and it is pretty good, but I wouldn't recommend it down to -50. About the coolest I've used it and felt reasonably comfortable was down to single digits. The ability to mix and match the layers is pretty nice and the bivvy sack gore-Tex performs pretty well - no doubt a good package to toss in the back of the plane.

Vick,
Yeah, I was thinking in real world terms, -50 would be pushing it.... but zero or so, in a survival situation, should be, well, survivable. I like that I now have what I (hope) I need in one bag, simple,