The more I think about it the less practical it seems...however...

When we talk about modularity with our gear as we so often do...and I like things to be modular...this idea might be more practical.

Just a loose example (it's too late to think any more than loosely ):

Carry the standard AR-7/US Survival Rifle as a survival rifle but carry the scoped barrel (plus optionally the action if you wanted) in the car or in the cart or bug out stash or whatever your preferred method is. If you were to stash one of those folding stock/pistol grips somewhere as well, you could assemble two whole rifles which depending on what you're preparing for might be useful. Until it arrives I won't know for sure if I can afford the space and weight but I'm definitely going to explore my options since there is a lot of aftermarket for it. For all I know I'll like it as is and won't want to mess with it.

The above idea is actually sort of what I do with fishing. I carry a tiny tackle box with the essentials and enough hardware to fish off the end of a whittled stick or a pocket rod (though I have never liked those). In my bigger pack (which the small pack slips into...modular!) I keep a travel rod with a bait cast reel. Combined I've got everything I need to fish most species just about anywhere in the usual way.

I think Chris hit it on the head. If you go that redundant, you get all off the disadvantages of the AR-7 rifle with all the weight and size of a more practical gun. Good for some...not so good for others. Yet another aspect of survival that is a personal thing.