Airsoft Extreme is now offering this, and is available in the multicam pattern from Crye Precision... "The Extended Go Bag is an excellent discrete carry rifle bag that has been modified from the original Go Bag to allow you to fit a broken down civilian length AR15 type carbines (up to 17.5 inches).  It is best used in combination with the SOTech padded foam inserts (link - p/n #xxxx) to protect the 2 halves of your rifle from cosmetic or impact damage. 

Also, the Extended Go Bag features 2 external pockets that are sized to each fit multiple 30rd magazines.  Side compartments can be used for accessories, cleaning material, etc. The main double zippers are mounted internally towards the body incase of zipper blowout during vehicle impact. The Go Bag is comprised of:

• A main compartment with double linked zippers (dimensions: 23' x 8' x 8')
• Internal hydration reservoir slot (canteen not included)
• 4 zippered flat side pockets for small items or documents
• 2 larger zippered external pockets
• MOLLE/PALS attachment webbing on both sides
• Padded contour single shoulder strap with quick-ditch side locking buckle
• Shoulder attachment points and carrying handles on each end
• Made in the U.S. out of military grade cordura cloth down to the webbing and fasteners to specifications of U.S. Special Forces

This SOTech Extended Go Bag includes the Foam insert. It divides the main Extended Go Bag compartment in two and provides impact protection for whatever you are carrying.  For Extended Go Bag use only.  Not for the regular SOTech Go Bag."