My thoughts on the topic - I have a few rifles... and spend a lot of time at the range. Based on personal experience:

1.) AR-15, I have a beautiful one that I built from a stripped lower receiver. Stainless steel fluted barrel, American Flag emblazened on the lower receiver, and generally above-milspec parts throughout and a high-grade bolt carrier group. It's actually chambered for 5.56, there are some slight differences and it is important to know that - I have some issues firing .223 with it (occasional jams, etc.). It's dead-on accurate, but loses that beyond about 250 yards (for me) - still tight groups, but you need to be very accurate with a small projectile. I wouldn't recommend it for hunting medium game, but it is excellent as a self-defense & varmint gun. If someone can really clip the ear reliably on a white tail at 500 yards... well.. you are better than I... and the Marine Scout Snipers might be interested in you. My handicap is that my vision isn't very good, so even with eyeglasses and a high powered scope, I can't rely on my physical abilities beyond about 250 yards. I'd never see the thing out there in the first place anyway.

2.) Remington .308. This is my go-to rifle for medium game hunting, and I'm considering an elk hunt in Montana in a year or so, I'll likely take this albeit with a better scope than I currently have on it.

3.) Marlin 1895S .44 Mag Lever. I'm not a fan of this thing, I'm actually putting it up for sale on gunbroker soon. I read someone else's favor of these things, but I'm not a fan of a lever action.

4.) Sturm-Ruger .44 Cal Carbine. This is a decent semi-auto I have, fairly collectible actually, made in 1964. It's very comfortable to carry / aim / fire, but the .44 magnum round is just not ideal for hunting beyond about 50 yards out in my opinion. However, it's the one I carry in the scabbard of my ATV if not the .45 carbine (below) if I'm just out on the trails. This has a simple 4-round tubular magazine and is extremely reliable, but the action can be a little sticky, no matter how much frog lube I put on it. I'm not sure I'd depend on it in the face of a charging bear. For that, realistically, I can send 50 rounds of .45 caliber down range very quickly instead...

5.) Archangel 7.64. This is the big-game gun I carry/use and is my go-to for most medium game as well. In the economic collapse/apocalypse, this has special favor as well. I started with an arsenal-grade, never-issued Mosin Nagant. I [carefully] removed the original walnut stock, wrapped it and it will be 'arsenal grade' forever. Then inserted (without modification) the Tula Arsenal Factory Mosin-Nagant into after-market Archangel stock kit. This adds a composite stock, adjustable check rest, 9-round magazine. The rifle's stainless steel bolt looks fantastic against the black composite. This is a big gun.. almost 60 inches long I think... I used a butane torch to heat up the silver solder the Russkies used on the iron sites, carefully removed them from the dovetails, and replaced with a dovetail scope mount.. the downside is, that is a ways off from your cheek in destance, however I used a long relief scout-style scope, and quite honestly, I like it to shoot with... so does my son. He can reliably rip a soda can apart at 500 yards. The 7.64 x .56R ammo is ballistically similar to a .308, but it's dirt-cheap... 480 rounds for under $100 in a spam-can. That's less than .223/5.56 for something that can realistically take down big game, is unaffected by a harsh climate, cold, etc.. and you can drop in the mud, pick it up, and it works just fine. The same reasons cave-dwellers around the world prefer an AK to an AR-15.. reliability... For $400, I can literally have 2000 rounds stockpiled. The only downside, it's big. This could be resolved by using the Mosin-Nagant carbine models, but I don't have one and have never seen one that I liked (to buy) for the price. However, it would shave about a foot off in length and use the same round. I guess you could also just cut the barrel, and I see many do that, but not something I'm willing to do with the example I have. Bang for buck though, you can do this for about $250 all-in if you don't care about how the Mosin Nagant looks that you start with. Look on YouRube for 7.64x56R plinking... sending a round through a cinder block... detonating a propane tank at 1000 yards..

6.) .45 Caliber High Point Carbine. I bought this because it was cheap, decided I LOVED it, and then upgraded it a big. Has a better fore-arm grip, picatinny rails everywhere for accessories (at least 6 of them), has a perfectly reliable magazine, chambered for .45 caliber (interchangeable with a side arm), and I recently put a holographic scope on it that takes nothing more than a glance on target to be dead-center. Here's what I love about it.. the .45 has decent take-down power at range, and a heck of a lot of it at short range.

My nephew is a marketing representative for Daniel Defense, one of the premier makers of AR-15 style rifles. He's also an expert marksman and shotgun shooter without peer. He finds the 6.8 mm barreled DD M-4 to be one of the best hunting firearms, using it to take down deer and feral hogs.

Personally, I like the 300 AAC Blackout version, and I have a DD "Ambush" rifle chambered in that round. The advantage of the 300 Blackout round is that it shares the same ballistic neighborhood of the 7.62 x 39 (AK-47 and SKS) and the 30-30 (lever action rifles), and because it uses the same brass as the 223 round, fits in the standard AR-15 magazines. Sharing the high capacity of the 223 magazines makes the 300 Blackout both a good hunting and defense round.

These discussions have been raging for years! The .223 is a perfect round for killing men that average 150 pounds. A deer here in the NY Catskills rarely goes much over 150 pounds. I hunt with a .308 but I never take a body shot and aim for the neck just so I don't kill and destroy the meat I am hunting for. Shot placement is the key to any and all caliber discussions and the difference comes from the powder and energy behind the projectile coupled with the type of projectile you are using. A .22 LR placed accurately in a deer's ear is just as deadly as a .300 Win Mag that could pass right through and fail to damage vital organs. How far your bullet must travel is the more important discussion in determining caliber to hunt with. My .223 Rem. model 700 can smoke a woodchuck at 500 yards so it will certainly do the job on a deer at that same distance if I place it right.

I had a Colt AR-15 HBAR (A1) and a Ruger Mini14 and sold both couple of years ago. I've truthfully never been too impressed with the .223 round. I have an M1 Garand US Navy National Match chambered in .308, and an original M1D with the M84 scope chambered in 30-06. For my money, that's the finest semi auto action on the planet.

My meat guns are a restocked/scoped British .303 thats pushing 100 years old and my trusted thutty -thutty for brush work. The .223 hunts better than a sharp stick, the fact is you can carry hundreds of rounds of .22 in a couple pockets, if you need to eat and defend from cover, that would be my choice -if only given one. its been my experience that anything shot in the ear drops.

Most of what I've read (with slight bias, being an NRA Lifer) is that the .223 round is most widely used for prairie dogs and coyotes. I've seen almost no mention of larger game being taken by this round. Even wild pigs are generally shot with .30 caliber and above.

I'm not a hunter (with the exception of the occasional skunk), but if I were, my Marlin 1894, in .38/.357 would be my gun of choice. I've always loved that rifle, even though I have many others (including three in .223/5.56).

I hunt with my Marlin 444.

Only need one hunting rifle. I prefer one that can take down a deer or an elephant at 500 yards.

One shot one kill. and if you hunting deer with it using Hornady Revolution rounds, and hit it straight on in the chest, you kill it and gut it at the same time. :)

I just bought a RRA AR15 and a RRA AR8 (.308) back when it looked like we were a vote away once again. Beautiful rifles! I do plan to hunt with them, although a lot of people complain about the weight of the AR8. I had never shot an AR until them, but it is a wonderfully American rifle, and it has lovely ergonomics (to me).

In doing the research around ARs, I couldn't believe how many people were hunting with them now. Clearly a 30-06 and .308 are far more powerful and have larger bullets, but when I see people taking a deer with .357 or .44 magnum pistols, it is clear that a .223 is more than adequate a round for deer. It is interesting that a few states require larger calibers than .223 (e.g. MD), and some states require certain muzzle energy for deer hunting ( minimum around the .223 +/-).

I also bought an M1 Carbine, which also feels wonderful. Have not shot this yet. That thing just feels like part of me when I hold it.

I've not shot an M1 Garand. My father used on, and qualified sharpshooter with a 1903. He didn't keep his though. When I hold them, they feel a little more awkward. The clip vs magazines kind of puts me off. I have heard the rifles are super rugged though.