I have a Win 70 Fwt which won't shoot 5-shot groups; the barrel heats too quickly. It shoots good 3-shotters, though. My Savage 99 and Browning A-Bolt are my only other CF rifles, I'll test them with 3's or 5's depending on my mood and how much of a particular load I built. I think it's more important to have a good consistent 3-shot from a cold barrel....and if you're REALLY lucky, from a cold, FRESHLY CLEANED barrel! How great would that be?
That said, I am a bit more impressed with the 5-shot groups; your rifle can be superfluously accurate, true. But it cannot ever be TOO accurate. I wish I'd never tossed out the target from my best-ever group from my .280 A-Bolt. About 1.5 inches for 10 shots at 200 yards. And truthfully, I'm not much of a shooter.