For example, using a .30 cal 180 gr bullet, how much faster gets your attention? 50 fps? 100fps?
For example, is 3300 fps from a 300 Weatherby THAT much better than 3000 from a 300 H&H? If so, where is your "break point" of better? If starting at 3000 fps, when do you say "Wow"?

Just my opinion... 50 fps, yawn. 100 fps, hmmmmm..... 150 fps, starting to make a useful difference.

For me there are a number of factors.
Speed vs recoil is the biggest, plus age of cartridge, since I like 'em well seasoned.
The Win Mag and the H&H are about on par, but the H&H is so much more interesting to me.
Find a trajectory with the sort of teminal performance you need from your chosen bullet, then see which round will best deliver with least powder.
If we just keep chasing the fastest round, we won't be satisfied till we have the 308x500 Jeffrey in a 40" barrel. And then someone necks the BMG down....

I'm happy with faster-than-magnum in a 26" bbl.
Some of the smaller bores don't seem to need more than the '06 case before diminishing returns kicks in full force.

People might not like this, but my "wow" point is about a 750 fps increase. This is what it takes to add another 75 yards to your point blank trajectory. And as far as killing power, just go to a larger caliber (heavier bullet) if you want more effective killing power at the target. More speed usually isn't good for your bullets, and if they come apart on hitting the skin of the animal you end up with LESS killing power instead of more. It's just much easier to go to a larger bore for more effective killing power.

Bullet speed does not hold me in awe, accuracy sure does. The fact that my 220 swift will produce well over 4000 fps with light weight bullets means nothing to me without accuarcy and proper bullet performance. In many cases extremely high velocity inaccuarte bullets are a terrible waiste of precious reloading components. Those speed numbers usually mean shorter bore life because more powder per round is consumed to reach those speeds. Bullet speeds in the 2500 to 3000 FPS range will give better bullet performance on game as long as we are talking big game animals. Small game animals with very thin skin light bone structures need light jacketed accurate fast traveling bullets. Those bullets produce explosive mushroom qualities on impact no matter what velocity they are traveling. The proper balance between bullet speed and bullet performance is the key. Firing heavy jacketed big game bullets at extreme velocities will cause explosive early expansion on close range shots and may not penetrate as desired. Extreme velocity heavy jacketed big game bullets at extended range may not expand or mushroom at all due to the thicker copper jacket. The proper balance of bullet speed along with bullet performance is crucial no matter what cartridge your shooting.

Dan's Theory of Relativity: It doesn't matter unless you can make use of it.

Put another way, at 100 yards, who cares? I've been told that X Bullets are not reliable expanders with impact velocities below 2000 fps, so if I can project that minimum velocity another 50 yards... Long range shooting? Every fps helps as long as you can hit your target.

My touchstone on velocity is set in concrete and I saw it, and didn;t experience it in person.

Until 1995, I lived in Sacramento, California and did my shooting at a range east of the city. I met a man that fired a 308 and did it well. I checked many a target next to his and my paltery inch groups paled next to his consistent three to five rounds in the same hole with his Remington. Then he showed up at the range with a 30-378. A buddy invited him on an elk hunt in Montana and assured him he was undergunned with the 308. Short story: The guy developed a flinch that made Don Knotts look calm. His one hole groups went to five and six inch. It brough home that velocity and recoil go hand in hand in a .30 Cal.

Using "conventional" lead filled bullets most times speed doesn't do much to enhance the performance of the bullet once it hits the animal.

Using a bullet made from solid copper is an entirely different matter. The increased speed helps in penetration using a Groove Bullet - custom made from solid copper. Our EXP bullet has two stages of operation. At high velocity the front of the bullet is designed to shred inside the animal and the back of the bullet then drives on through. Since hunting seasons have already started in a lot of the western states we are receiving feedback from customers. The 2 stage process is and does work very effectively.

We had one customer that killed his elk using the 7mm 127gr EXP. The shot was made at 537 yards and the bullet exited. He used his 7mm RUM and started the 127gr bullet at 3800 FPS.

Using a lead filled bullet I can see where at high velocity it could mushroom violently or completely come apart and not provide the wanted penetration.

Matching the right bullet to high velocity and accuracy for the right animal is a lethal combination.

Don

Personally I consider 100 fps or so nice to know but when you get to 200 fps and beyond, you're starting to talk about a real difference. However, I don't really look at it like a velocity advantage.

I look at it as a cartridge that's capable of more velocity with the same bullet is also capable of the same velocity with a heavier bullet. For example, a RUM shooting a 200 grain bullet the same speed a WSM shoots a 165.

That changes the question to "How much heavier must a bullet be to make a significant difference?"

I know many will pipe in saying you can shoot the heavier bullet in the smaller round at a lower velocity (like the original question), but the simple fact of the matter is people generally don't. You'll have to ask them why.