There are multiple factors to consider:
- how much will you shoot? Price of ammo/components will start to add up & barrel life becomes a factor
- will these be dedicated to target use?
- Do you need to feed from a magazine
- Do you plan to reload & are you ok with pretty much ONLY reloading?
- If you're going to shoot alot, the smaller the cartridge, the more economical it will be to shoot.
- If you are going to dedicate these to target use and don't need to feed from a magazine the short/squat 6's are amazing (6BR, 6XC, 6 Dasher, etc)
- If you reload and plan to, you won't need to worry about commercially loaded ammo availability.
IF the stars align on the above - I don't think you can find a better choice for 1000 yards and under than the 6BR ... you can find some as good, but not better. And yes - there IS such a thing as an "inherently accurate" cartridge ... and without any question, the 6mmBR is absolutely one of those - and it is a SAAMI standardized cartridge.
If not the 6BR, I'd look to the 6.5mm Creedmoor or 6 Creedmoor next but the 6 creed is a bit more finicky to develop an accurate load in and you and your wife will need to wear matching shirts with either the 6 or 6.5 creeds
... but ... the 6 creed is one of the VERY few cartridges for which I see ammo available for on the shelf every time I drop in the local stores. If you are wanting to be able obtain and shoot commercial ammo - I think the 6 creed and the matching shirts makes tons of sense right now.
My 6BR is one of my most economical rifles to shoot (lapua brass that lasts and lasts, 30g of powder, lower cost 6mm bullets as compared to 6.5mm, 7mm, & 308). It has excellent barrel life. It is my most accurate rifle and almost any load I put it in shoots amazing - under 1/2 moa - some under 1/4 moa and it is just a factory savage action with an ER Shaw barrel - nothing fancy. It has virtually no recoil with the 26" heavy varmint barrel (.850" at the muzzle) such that I haven't even threaded it for a brake. It has rung steel many many times at 1000 and when I take a group to the 1000 yard range, it is always everyone's favorite rifle to shoot - at any distance including at the longest ranges we can engage at 1000. This is in comparison to also having 308, 7mm-08, 260 Rem AI/6.5mmAI, 223 with us.
If you want to go further than 1000 - you'll probably need to step up to a caliber with higher BC bullets - 6.5's and 7's begin to look attractive as do the very heavy 30's ... but ... then you are really increasing cost to shoot and the wear and tear on the shooter (recoil) unless you stay with the smaller capacity 6.5mm cartridges like the 6.5 creed and 260.
My short list for what "I think" you are trying to do and in order (
so long as you reload) is:
- 6mmBR
- 6.5mm Creedmoor (better barrel life than 6 creed)
- 6mm Creedmoor (ammo is available as are components)
If you DON'T reload, the list changes slightly to the following:
- 6.5mm Creedmoor
- 6mm Creedmoor
All this being said - I am neither a lover nor a hater of a creedmoor. It is both overvalued and overly poo poo'd simultaneously. It gets a bad rap as well as way too much credit. It is solid and very well suited to long range target work to 1000 yards in either the 6.5 or the 6mm version - a bit longer in the 6.5 version ... but ... so is a 6.5x47, and a 260 Rem, and a (insert others) ... but it has momentum going for it and that is the reason they are on my short lists above.
Whatever you decide - if it is a 6mm or a 6.5mm bore - you will need an 8twist barrel so you can shoot the 105-107's in the 6mm's or the 140-147s in the 6.5mm's ... that's where you will get the high BC's that will extend your supersonic range to 1000 yards and beyond.
Good luck!