6.5 grendel or .223 for training target rifle 300-700yds

[Str8shooter1]

Im looking for a lower recoiling, heavy barreled rifle option to get a couple more rounds downrange while my hunting rigs are cooling down between shots (my 300 win howa gets burning hot after 5 shots and starts stringing bad, and takes 15 minutes to cool back down). Instead of twiddling my thumbs Im hoping to continue practicing shooting out to 700 at moa targets in varying winds. I will largely be using factory ammo and im debating between a .223 like the Tikka Varminter (1:8 twist that can stabilize some heavier rounds) or a 6.5 grendel in howa mini action or ruger american/ranch.

Is the .223 the affordable answer or will I be bummed trying to get factory ammo to print moa or less and if the wind is 10mph+ trying to shoot past 500?
Is the 6.5 recoil soft enough (8lbs) to spot shots through a scope? Can I shoot the grendel more than 5 rounds without stringing in the heavy barrel howa?

Other questions/calibers I should be focusing on?

I plan on mounting a FFP dialing scope (Trijicon 10mile) on this gun.
Thanks

 

[RB II]

I use a Rem 700 varmint 223 for just what you are talking about (varmint hunting as well). 26" barrel, shoots less than .75" groups at 100 yds. I load the 55 grain SGK bullets for mine. It isn't really good beyond 500 yds or so.

I also have a 260 Rem rifle that got built wrong with a super heavy barrel on it. Rather than deal with the wrong barrel error and the gunsmith, I just turned it into my dedicated practice rifle. Works pretty well to a good bit beyond 700 and I didn't lose a friend.

The recoil from either rifle is negligible and very inexpensive to shoot.

 

[bamban]

Get a heavy barreled 223 with 7 or 8T. If limited to factory ammo, grab a case of Black Hills 77SMKs or 77 TMKs. The IMI MK 262s with 77s also shoot well. Any of the 3 factory ammo will serve you well to 700 yards. Any of these will shoot MOA, provided the trigger puller can.

 

[FrogFire7]

I don't shoot factory ammo, so I might not have the best answer, but to me it's tough to beat a good fast twist 223 with heavies in it for long range practice

 

[cajun]

That 223 will teach you to read the wind.

 

[sierracharlie338]

My 223 bolt gun is a blast to shoot. That being said I prefer my Grendel past 500 for a little more feedback on steel. Yes you can spot your hits with a Grendel.