Cold weather sleeping gear???

[Cpl Punishment]

The USGI modular sleep system is a nice setup. It really isn't that heavy, but it is bulky. I think it only compresses to 11"x18". However, just the patrol bag and bivy sack will become very small. So when you don't need more than a 30 degree bag, it's a good combo. The big problem I have with it is that while it doesn't become real small when compressed, the bags are fairly small inside. I'm broad shouldered and find the bags confining.
The older ICW (15 degree bag) and ECW (-20 bag) are larger, and give a much better night's sleep, IMO, but they do, individually, weigh as much as the entire MSS.

Synthetic or down, bivy or no depends entirely ont he climate you're going to use them in. Guys have said they don't like bivys, but where I live, it rarely gets below freezing and bivys are a Godsend.

Re: wearing clothes in the bag. Another thing that can be a problem is if your clothing it too insulative. "What!? You're nuts!" Nope. For instance if you sleep in a jacket or heavy sweatshirt, your arms might be cold because the sleeves insulate them from the heat given off by your torso. Same reason mittens are warmer than gloves. If you nee dthe extra warmth, wrap a jacket or sweatshirt around you with your arms inside the torso, not in the sleeves.

 

[Mikel_24]

...Another thing that can be a problem is if your clothing it too insulative. "What!? You're nuts!" Nope. For instance if you sleep in a jacket or heavy sweatshirt, your arms might be cold because the sleeves insulate them from the heat given off by your torso. Same reason mittens are warmer than gloves. If you nee dthe extra warmth, wrap a jacket or sweatshirt around you with your arms inside the torso, not in the sleeves.

+1 If you have a primaloft or down filled jacket, don't put it on, just wrap yourself on it. You will be fine inside the sleeping bag with fleece clothes though... because they are not so insulative.

...Also, Nextec requires no DWR treatment ever to keep from wetting out. Each strand of the fabric is coated with silicon. This last factor recommends it to the military, and it has been adopted for two (or is it three?) layers of the latest version (Gen III) of the U.S. Extended Cold Weather Clothing System (ECWCS). It is also showing up as the outer layer of pricy down-insulated garments...

Mmmm I didn't know about Nextec but I will try to find out some more info about it. Thanks Thomas! For the outer layer of down garments I have used Gore Dryloft (which breathes reasonably well) and Pertex (which is not whaterproof but sheeds snow like a chapm). That Nextex seems worth trying...
Mikel