It has exploded in the last year.

5.56 isn't going anywhere any time soon.  Yes, there are good alternate options that have traction.  No, none of them will ever rival 5.56 in availability or use any time in the near future.  Every rifle company makes a 5.56 gun.  They don't all make 6.5 Grendel guns, 300 BO guns, 6.8 SPC guns, 6.5 Creedmore guns, or whatever else have you.  The one exception might be 7.62x51, but that's a far cry from 5.56.  Either way, 5.56 is going to be the standard for a while.  No one is in a rush to replace it, certainly not our currently underfunded military or NATO.

Correct ... Not to mention that in the aftermath of any realistic SHTF scenario  - where folks have actually engaged with 5.56 weapons   -  there's going to be oodles of unspent 5.56 ammo in still-loaded mags to be scrounged off all the dead bodies who suddenly have no need for them anymore.  

Correct again, ... the practicality of the 6.8 is way overrated by internet commandos.

Correct x 3 ... Nice hat-trick  The practicality of the 6.5mm is way overrated by its internet fanboyz.

Hence, by default, the only practical and logical choice for any reasonably realistic SHTF scenario (which necessarily excludes those involving hordes of mutant zombies or some invasive alien species from Alpha Centauri) -----> is the 5.56 cartridge.

Yeah, but shtf wasn't really my main requirement.  Although it's always a consideration.   I said price / availability / and longevity were the criteria.  To shoot.  Meaning under normal circumstances.  

5.56 probably is a super good choice for SHTF.  But even then I don't claim to know what will happen.   And really, on ARfcom we feel like AR's and 5.56 are the most prevalent gun out there, but I wonder if that really is the case.  I know it definitely has grown in popularity.  But I still wonder if .30-30 and .30-06's would still be the most common calibers floating around most homes in america........  I don't really know but I know they were pretty darned prevalent.

I recently decided to pick up a bolt action to take Randy Cain's Practical Rifle course and to play with. I settled on the CZ 527 Youth in .223. It will be a range toy so I picked .223 for decent trajectory and cheap ammo.

I hope to use the lessons learned at Randy's class to set up my pre-64 Model 70 .30-06 as my primary hunting rifle (replacing a mis-mash of lever and bolt guns) and to take Gunsite 270 with. I only want to modify the Model 70 once and the lessons learned should translate fine. A Winchester featherweight compact in .223 would have been a better understudy but I have always wanted to play with the CZ micro-Mauser action and it was almost $200 cheaper. Of course I'll spend that $200 in magazines...

The criteria you just named only re-Inforce Travis Haley's precept that "it's a 5.56 world."   Even "under normal circumstances."  So spend and acquire accordingly.

Actually it's the best choice in this country ... That said,  I'm a strong believer in not putting all your ammo "eggs" in one "common" basket.

So I've got an ass-ton of surplus 7.62 ball and mil-spec .308 FMJ ammo laid back and dispersed locationally ... primary weapon being a suppress 16" LMT LM8. Failing that, there are also a couple of .308 M1s and M1As.

Hard to see a down-side there.

Why limit yourself to bolt action?

Because I like shooting them.  

I like shooting my 1903A4 too, but given your stated cartridge criteria it wouldn't be the first choice for reasons of both caliber and action-type.

It's a detachable magazine-fed, semi-auto (at minimum) world these days.  

The first choice for who?  You?  You're not me.  I have 5.56 / .308/ 06 autoloaders.  What I want is a bolt action in a more intermediate, lighter recoiling caliber.   Why would you argue about that?  People buy all kinds of guns that are for reasons other than what you think they should buy them for.  

I'll be honest, that's just irritating.

With the right ammo and skill on your part .223/5.56 will do 600 yards all day long. I agree with you that bigger is preferable (or maybe needed depending on your state's laws) for deer but the truth is .223 will kill deer all day long. I think you need to decide which is more important, ammo cost/availability or hunting/longer range shooting. If the first buy a 1/9 or 1/7 .223 and don't look back. If the second buy a 6.5 G. I really think for what you want a CZ 527 or Howa mini action in one of those two will handle your needs.

Another thought that is not based on experience as I have never owned a 6.5 G. If you go 6.5 G maybe go with a short (.308 length) action for seating out longer bullets if you handload for it to supplement factory ammo. The nice thing about a bolt action is you don't need a Dillon progressive press to feed it...

FWIW..

What you seek, is the
Is the 7mm-08, shooting the 140grain projectiles.

Superior ballistic match up, flat shooter, light weight easy recoil, inexpensive  to shoot easy to reload.

Absolutely fits and exceeds your criteria.

I have never found the difference between the 7mm08 and 308 shooting 150's to be noticeable.  I like the round accurate, plenty of pop.  But after shooting several I don't see enough advantages to use it over the 308 which is cheaper to feed and easier to find.  The OP wanted something with less recoil than the 308 and a intermediate caliber don't consider the 7mm08 either.

Gawd, yes.

If the OP dudenal is still paying attention  , ... the .308 has it all over the 7mm-08  -  unless it was some sort of specialized bolt gun for which only the 7mm-08 would do.

Otherwise, general use prevails  -  especially considering the .308's cross-over use as between bolts and semis, which would be especially important in SHTF situations.

Yes, still watching.  Still thinking.  Still sifting.  I don't ever do anything fast when it comes to buying guns.  In fact, I'm selling stuff off right now cuz we need the money.  But if I sell enough stuff I might have room to buy something I think that I really want.  

But therein lies the rub.  I think I'm just really particular as to what I like, but I've yet to figure out what I think would be like the best set up.  I wish I had 1 rifle that was a go to, do it all gun.  But I'm not sure it's a fair task to fill.  

There's so much gear out there, and I've not experienced it all.  But for me, I have a lot of guns and they all feel like, just not quite right.  I know what aspects I like, and I have a pretty good idea of what calibers are good for what and such.  And I've got experience hunting with a few different types of guns.  

As far as .308 goes, it is a good caliber to choose.  It does kick, and if I wanted my rifle to be really light weight, I would not want to shoot it very much.  And to me the sweet spot of a rifle is not overly heavy.  

I have guns that I thought would fill this bill, but there is always something keeping me from being completely satisfied.  

It probably seems like I'm delving into a different area, but part of the exercise of figuring out the best intermediate caliber would be to go with this "ultimate", do it all gun that I seek.  

I'll give you a few examples of what I mean by things not being quite right.  

After shooting  a while, my goal was to make the M-1 Carbine my go to rifle.  Well, long story short, I just don't trust them like I do ARs as far as reliability.  And despite the fact that I like a traditional stock more than a pistol grip stock, the length of the handle on the M-1 Carbine firing grip is longer than say a Garand or M1A and feels awkward to me.  Thus making the ergos kind of blaaaaa.  I do like how light they are.  But of course range is an issue.  I did shoot them out to 300 yards, but there again, I always found an AR to be easier to make hits with at that range.  

So then there was the M1A.  I wanted one of these to be my do it all gun.  Well, I have a loaded and it's just too heavy for a gun I'm going to carry around much.  

And then there are AR's.  Well, my favorite configuration of an AR is a 20" rifle, with a rifle stock.  Govt' profile.  A1 or A2 is fine with me, although I don't like the triangle handguards.  So here we go, I have a 20" A2 and it is a great gun.  Colt.  But that thing, it throws the POI between different brands and types of ammo so badly, it makes it not really a good choice for a do it all SHTF gun.  Lets say I got it zero'd for some M193, well M855 is 3" to the left at 50 YARDS!!!  At 100 that's going to be 6" off to one side.  It's just annoying.  Then I have two other AR's that are carbines that are less finnicky but they just don't do it for me in the ergos like the A2 does, because they're HBARS. And the irons on my M4gery don't do that great with my aging eyes.

  And then there is the will I be OK with 5.56 with reading the wind at longer range and compensating.   In theory I thought my Recce was going to be my go to gun, do it all.   But it's so front heavy to me once I put a scope on it, I don't shoot it very well off hand and the balance is blaaaaaa.  

Personally these are the guns that I THINK would trip my trigger but buying them and affording them are not the easiest, as we don' have a lot of money.  Like no extra.

A 605 with A2 handuards
An A1 with A2 handguards
A 723 with possibly some kind of optic on top.
An A2 dissy
An M1A, standard or scout, heck even a Socom with different sights.  (but admittedly, these are probably just too heavy to consider a gun I can carry for any length of time, I'm getting old)
A bolt gun with some do it all caliber, with either some really good iron sights or a LPV or both.  

But yes, in theory I like .308.  It's just that for it to be comfortable enough to shoot much, it would have to be in a gun heavy enough that I wouldn't want to carry very much.

I have a Marlin 336 in .30-30 (Actually, it's technically a JC Higgins but I'm pretty sure it was made by Marlin rebranded)  and I love how that thing balances and it's pretty accurate.  But obviously capacity is limited, as well as range.  Although I think it can be extended with leverrevoloution ammo, eh?  

Yes, I need to just pick one and make it work.  Which is basically what I do.  But I'm all for trying to find the one that is optimum.  

I do the same thing with pistols and I've yet to figure out what my sweet spot is.  I thought I found it with a G26 but there again there's just things I don't completely like about it.  I carry a 442 every day and my bedside gun is an XD45.  

I've also been in the camp for a long time that really, for me, serious guns are pistols.  If the SHTF, I probably would be so beat that carrying a rifle will just be a bridge to far.  But I like shooting long guns so much.  LOL.  

So, I suppose this is all an exercise in fun.  And I should really be focusing on what pistol is better than my 442 for a do it all SHTF gun.  I will say that I don't think that would do very well for hunting deer or game if I had to shoot something to eat.  

So that was a whole lot of wow.  And really, in the end, I just want a bolt action in a lighter recoiling caliber because I think it could be useful for hunting, and a crap ton of fun to shoot.  

Get a Tikka in 6.5 CM

hmm with your description and my experiences with what has worked for me. I think a 16" dissipator is worth a try! a mid length gassed a2 dissy with a free float or a2 handgaurds would probably handle very nicely.

I built a a2 stocked, a2 16" dissy with a DCM free float and a2 handgaurds that thing was perfectly balanced and was my favorite AR excluding my RECCE. I do plan to make another one day. sold it like a dummy.

if you want a little extra horsepower then do the same build in 6.5 grendel

I still feel a pinned and welded or sbr'd gen 2 small frame .308 or 6.5g recce would be the ultimate "jack" rifle a 1-6 (or 8) optic and weapon light/sling and done!

All of the calibers you are talking about are pretty much AR specific, but you want a bolt action. Most of those calibers are work around to shoehorn a more powerful round into an AR. I would not buy a bolt gun in any of those calibers, except .223, because it actually started as a target/varmet round, but I'd still just get an AR.
Personally, I like .30s, so my only modern bolt gun is a .30-'06. .308 would be my second choice. The recoil doesn't bother me.
If you're looking for a round for the AR, I'd say 6.5 grendel gives you the best long range, while 7.62x39 is the most plentiful and cheap round. Both are about the same inside 150~ yards. 7.62x39 is a little more powerful than 300BO and as far as I know there is no cheap option for 300 ammo.

Intermediate cartridge is a specific family of cartridges developed for specific purposes, it does not include .308 Win/7.62x51mm NATO, 6.5mm Creedmoor, .243, .260 Rem, etc.

So you may not be looking for a true intermediate cartridge, such as the 7.62x39mm.

Some have suggested the 6.5mm Grendel. Good option and available in bolt guns. Inexpensive steel case ammunition is readily available which can be used plinking on steel
to about 500 yards. Good factory support. Has exploded in popularity. I tested a Howa bolt gun and it shot well, was light and handy and a lot of fun. Or you could just
buy a Grendel upper for your AR. Drop it on and shoot it. I know a lot of locals here are now hunting with 18 inch Grendel ARs and really like them.

A 6.5mm Creedmoor is a great cartridge for bolt gun use. Very accurate and has a very long reach. I've shot out to 1,500 yards using a Creedmoor. Great cartridge.
Just no inexpensive ammo.