New mountain rifle considerations

[texansport]

Hi guys - considering building my first full custom/semi custom rifle. Looking for some reassurance.

Requirements:
-Finished weight under 6lb. Where I hunt is desert/canyonland and 20 miles in a weekend isn’t uncommon.
-Barrel length of 20-22” because I’ll be threading on a 6” Scythe-Ti.
-600 yard capability on aoudad, I would personally like something 6.5 PRC energy or greater. I also hunt whitetail and mule deer.

I currently carry a sako S20 in 6.5 PRC with a 24” barrel that weighs 9.75lbs (finished) and want to shed some weight. It’s a dream to shoot with virtually no recoil with an area 419 - 4 port.

I also have a Sako Finnlight 85 in 30-06 with a 20” barrel in 30-06 that I don’t enjoy shooting because of the recoil, it’s 5.75lbs bare and not threaded. 30-06 also isn’t as cool as some of the newer cartridges.

Looking at a couple options:
1) Thread the Sako Finnlight and run the 30-06 (highest recoil, cheapest option)
2) Rebarrel the Sako Finnlight in 280ai (lowers recoil, gain BC, gain barrel threads)
3) Go full custom or semi custom with a T3x super light platform in 6.5 PRC/280ai (lower recoil, custom gun fun factor, highest cost)

I think I’m splitting hairs here and writing this out makes me lean towards option 1 or 2. Am I losing too much velocity with a 20-22” barrel that a 280ai or 6.5 PRC isn’t worth it? I like to be over gunned, Is there a better cartridge for a <6lb rifle that still carries >1500 ft/lbs at 500 yards?

Thanks y’all!

 

[B_Reynolds_AK]

1) Pull up your favorite ballistic calculator.

2) Pick your favorite projectile. Start with 6.5mm. Around here you'll find a strong preference for match bullets such as the ELD-M. Why? Because of the data.

3) Play with Muzzle Velocity in the calculator with the B.C. of that bullet and see what velocity you need to start at to hit 1800-2000 fps at 600 yards.

4) Once you see what you actually need for velocity, choose the cartridge that matches that.

5) Less recoil equals higher hit rates.

6) Ft./lbs is irrelevant.


Hint: A 6.5 CM with an 18" barrel shooting 140 ELD-M's surpasses your requirements.