Here's my thinking on efficiency and simplicity, based on about 40 weeks in the field over the last 8 years. There are bound to be people wondering what to buy and why for these high-action shooting trips and this should be the place they start gathering ideas so feel free to pile on.
Ruger .22-250 and .243 rifles got the job done on my first trip and convinced me this was my main focus in future shooting. Switching to .223 Rem was a no-brainer. Gobs of relatively inexpensive brass available, uses half the powder to develop 90% of the muzzle velocity with 10% of the throat erosion of the .22-250. Since I meander in the field for Prairie Dogs (PDs) carrying about 330 rounds, I also appreciate that .223 loads are smaller and lighter.
A Remington 700 Short Action Tactical (20" heavy barrel) rifle replaced the .22-250 and soon wore a Bell and Carlson Tactical Medallist synthetic stock which lightened the rifle a bit. Timney trigger, an AR magazine adaptor and a muzzle brake made it ideal.
Then I picked up a Stag Model 6 Super Varminter with its 24" bull barrel. Incredibly accurate, lightning fast recovery after every shot. It's difficult not to "chase" the PDs - fun, but terribly inefficient. However, it provided field experience with a semi for comparison.
I've since also used a Howa 1500 heavy barrel and a Mossberg MVP. I put over 14,000 rounds through that first Remington, thousands more through the Stag and Howa and about a thousand so far through the Mossberg. I am truly opinionated at this point.
The bolt guns are for me. Here's why...
If for any reason a round won't chamber I can feel it immediately and stop forcing the bolt.
The semi often damages the round if it doesn't feed smoothly.
The direct impingement ARs blow gas back through the chamber camouflaging the case which lands 8 feet away in the brush. I'd rather shoot PDs than search for dirty cases. I admit I had some success with a catch bag on the AR. When full, it caused jams so I cut off the collection bag and simply used it as a deflector so the cases landed beneath the rifle. The deflector required constant adjustment to keep it in place. Many ARs mangle the case mouth and/or dent the case body. I don't need that.
From a sitting or standing position I can work my bolt quickly and catch the case in the air. It is never too hot to touch. From any position when the firing gets hot and heavy I can deflect the spent cases with my hand so they land in front of me in a polite, shiny pile, easy to see and collect.
When I've finished shooting in one spot I leave my bolt open to allow the chamber to cool and to prevent a round from heating up in a chamber that's just been heated by as many as 90 rounds fired in quick succession. I can clear the chamber of an AR and lock the bolt open but it's a separate action I might have to do a hundred times a day. No, thanks. Some bolt rifles have their bolt release levers mounted in (too) convenient positions beside the bolt. The lever can be tripped accidentally, releasing the bolt. Most inconvenient, indeed. I modified the release levers on my Mossbergs so they can only be pressed on purpose. The Remington release is inside the trigger guard and not likely to be tripped accidentally.
There is at least SOME velocity loss associated with the AR gas operation. Bolt guns maximize muzzle velocity. A small thing, but it's there.
Here's a real plus, though...if you started off with SRS processed brass you may very well reload cases until the primer pockets stretch unacceptably before you ever have to trim again and if you aren't anal about a jewelry shine to your brass, you might not even have to clean cases again...and from a bolt gun you can merely inspect, decap/neck size, prime, charge and seat to put the brass back in action. No case lubing, no tumbling, no media in the flash holes, no drying time, no mess.
Finally, an anecdotal plus - I have 4 .223 bolt rifles dedicated to PDs and a neck sized case from any one will chamber in any of the others!
I am indeed a lucky man.