My Hospitaller has a 26" barrel and a TBAC brake installed. It is right about 50" and fits perfectly into a Tactial Taylor Sniper Drag Bag, which is listed as 51" in length.
GAP makes great rifles and I have been very happy with the Hospitaller. I actually have two, one in 6.5x47 Lapua and one in 6.5 GAP4s. They are heavy bastards, but both are absolute tack drivers with very smooth actions and a great fit and finish. The Bartlein barrels have also proved to be very consistent, cold and hot. You will not be disappointed, but your shoulder may not appreciate it much. Especially after a 5 day Coues backpacking hunt
As for bags, the Tactical Tailor bag is the only one I have tried, but I have been very happy with it as well.