Aye Up Sunndog,
Liker Badger74 I too have done this before, in fact several times with different types of jacket/different cam patterns/different h20 proofing etc. It can work if both jackets are of the same or a similar cut - if not you can end up with overstretched material in one garment and bunched up in the other. The pocket arrangement needs to be similar too - if not you can end up with either no place to stow things when you invert the garment or stuff in an awkward position. Dependent on the type of materials in each jacket and the way in which you join them together you can end up with a) a heavy garment b) a not very breathable garment c) an uncomfortable garment d) a garment that doesn't dry out easily after rain/perspiration e) a garment that is difficult to wash and dry - etc. If the outside of the garment gets wet and filthy and you then need to invert it you end up with *@!! against your under-layers. When all is said and done it is far less complicated to carry an extra (or more) lightweight over-smock(s) which can be donned almost as quickly as taking off and reversing a back-to-back garment. If carrying the extra smock is an issue - having gone down the route (operationally) - I found the best result was to create an internal pouch across the rear of the jacket (like the old Brit combat jacket) from the hem upwards, making it large enough to stow a lightweight (and usually h20 proof) smock without having to fold it too many times, that meant the extra garment was with me and the bonus was an inbuilt waterproof seat! Hope this is of use to you.
