Are you talking about hunting, LE tactical work, or just going out far afield shooting? If for hunting or LE, I'd venture to say an Eberlestock pack with built in scabbard should work just fine. This would give you the option of hauling all your gear to a spot. From there, you can do a couple of things..... Take out rifle & sling it up & carry on, leave some gear at camp, or other place, carrying the rifle & lightened pack, or keep it all together, dump the pack shortly before taking the shot. You have lots of options.
The Eberlestock Gunslinger II is similar in size to the Rush 72 with the addition of a built in pull out scabbard. You can use this scabbard for a rifle, or for other gear. If you want to go bigger, look at the Operator - if you pack a rifle and really fill this pack up you may find yourself at the limit of what you want to carry for long distances.
i have a short tac-ops and quite honestly it's my transportation bag. Going out on a limb here, but I'd venture to say that a high percentage of folks on here don't use their tac-ops bags mainly as a drag bag. Some probably do, but many of us get them because they are just a damn fine case for protecting our rifles and for whatever reason go with a drag bag over say something like a hard pelican case.
I also own a 5.11 Rush 72. The way these are made & set up it excels as my work bag back & forth between home & the fire station. All the small pockets & zipper compartments just work really well for all the shit I carry back & forth. I suppose it would work ok in the field too.
My Eberlestock Gunslinger II works very well for outings going shooting for the day or deer hunting. It holds either my AR or bolt gun, jacket, first aid kit, hydration (bladder or water bottles), spotter, tripod, range finder, binos, ammo, etc. In fact, it sometimes feels like too much pack on a long walking hunt mainly cause if I have the room, I admit I take along too much shit!
My Operator is even larger. I haven't used this on a hunt yet, but if you are humping in lots of gear this bigger fella will do the job & still carry your rifle in it's scabbard.
If you are looking for a pack that will carry your rifle and work well to hump out something like deer or elk quarters, something along the lines of the Eberlestock J107 Just one might appeal to you.
Eberlestock also has packs that you add a separate scabbard to the pack vs the ones I've mentioned that have scabbards built in which you pull out the bottom to use.
If your uses really find you humping in to a point, lightening up and then dragging from that point, separate pieces may be the way to go for you.
Truth be told, if I were to do it all over again, I don't know if I'd buy a tac-ops again. I'm not saying there is anything wrong with it at all. It's arguably one of the best if not the best built bag for the money. Since I use mine mostly just as a transport gun bag, I can honestly say that I could get buy just using one of my Eberlestock packs. I do use the tac-ops a lot, but also take along to much other shit, and then the drag bag gets to be a damn heavy bag. Going from house to truck, truck to shooting spot is no big deal, but I'll be damned if I'd hump it very far afield. This is where one of the packs excell.
You have lots of options. Take a step back and ask yourself what you really plan to do, what you really need and/or want , then go from there. Otherwise you'll end up like me with a lot of gear, some of which is overkill. Nice to have, but not all is necessary.
Good luck.