Sleeping Bag System: review of the 4 in 1 modular sleep system with Gortex bivy cover

The "Debris-pee" 3-4 person shelter complete with fire pit

Shelter is one of the most important factors if you are going to survive in the wilderness. It's also one of the most important factors in whether or not you will be comfortable and cozy.
I've made and slept in all kinds of natural shelters made from sticks, leaves, and plant parts and in all kinds of weather conditions. Some of these shelters were quite amazing in that I was able to be warm (and even hot) in the cold of winter or dry in the heaviest of rains. While knowing how to build your own natural shelter is a skill that can bring a person to a fantastic feeling of confidence and freedom it is not what I am actually here to tell you about. Instead, I'm going to review a modern sleeping bag system that has been my favorite sleeping bag to date.



And here it is...

This is the "Military Modular Sleep System" which includes 2 sleeping bags; a cold-weather bag rated to -10 to 30 degrees (I know, that's a big range), and a lighter bag rated to 30-50 degrees.

Each of these bags can be used alone; the heavier for a fall/winter/spring bag and the lighter for a summer bag, or they can be combined for a really warm winter bag. For me, this is one of the attractive features because it becomes a 4-season, all-weather sleeping bag.


There's also a waterproof goretex camouflage nylon bivy bag that one or both sleeping bags can slide into so you can stay dry. It also adds another layer, although thin, of insulation. Remember to keep your gortex clean so it can remain breathable! All of this combines for an overall rating of -30 degrees!

It all seems quite durable and I've been using mine for about 4 years (including the lightweight bag in the summertime) and there are no rips, tears, or seams un-stitching.The whole thing packs into a black compression stuff sack (included). This sack is durable and covered in straps. If carrying on the outside of your pack it could catch on branches, which is more of a concern if you are going off-trail.

Not everyone will like the camouflage pattern but I personally prefer earth-tones before bright colors as I enjoy blending into the natural landscape when I am out.

I can personally attest that this sleeping bag system kept me warm in -15 degree weather (with some base layers of clothing on too). I've also slept out all night in the rain a few times and stayed completely dry inside. The bivy covers your head and has some air vents for circulation. The bivy proved to be breathable as it stayed dry inside when I've used it in the cold and in the rain.

The cool thing about this is that if you have a rain cover for your backpack then you don't need to carry a tent, meaning you can pack lighter. One other thing I like to do is leave my therm-a-rest mat at home and just pile up a foot or so of leaves on the ground to sleep on. The leaves will compress a lot but it will add insulation from the cold earth. I recently watched a friend of mine actually build a rectangular bed with branches and then a thick layer of leaves on top. In the end, he was about a foot off the ground and he slept deep and warm.

CONS: The major drawback of this sleeping system is it's bulk and weight (about 10lbs.). Compare this to a cold-weather down bag that may weigh about 1-2lbs. It does take up a good amount of space so take this into consideration. 

The summer bag can pack up as small as any other summer bag and I use a small Granite Gear compression sack to pack it in instead of the large black bag it comes with.

Here's a thought... what if they made these bags with a down fill?! It would cut back on weight and bulk.