Magnum bolt face, short action, 6.5 bullet, short barrel.

[Mike D Texas]

You are likely going to have to get into non-SAAMI chambering to get there.

I have a 6.5 SAUM improved with a 45° shoulder in a 21” barrel that gets 144 Bergers to 3150 with H1000 powder.

ELDMs seem to pressure up quicker for me but I think you could get there or very close with a 6.5 SAUM improved. But now you are into custom dies and reamers.

 

[HandgunHTR]

Going to have to slum a 6.5 max or 6.5 mega to get close with that barrel and action length

I just built a 6.5 Max with the intention of getting a 147 to 3000 with a 20" barrel. I am doing it with a Tikka action and a rechambered factory Tikka 6.5 Creed, so it may be a bit slow. Just started load development, so I don't know where I am going to land yet.
However, I am loading at just over 3" so a standard short action may not accommodate that round. Also, I am not sure you would get 3000 at 17" even with this cartridge however.

 

[SlimCreaper25]

I don't think it's doable. I run a 20" 6.5 saum nearly at pressure with 156 and 570. And they're longggg. It's 3.150ish? I can't remember. They're going 2940

 

[coyotekilla]

At some point physics / balistics just has its limitations... I'm glad you also didn't want a barrel life of 5k rounds...

My thoughts, a 6.5x300wsm or 300saum

There was a thread I was reading for amusement about resizing 277 furry hybrid cases into I think 243 for some interesting results. That being said, I have no interest in having my face next to 85k psi... I'll keep my brass cases and long barrel life, thank you very much.

 

[khuber84]

Go big case on a long action, the only way you'll get what you're after.