Looking for opinions on the expansion of round nose vs spire point projectiles when all other factors are equal.
Same manufacture, weight, velocity, ect.

I think you can find charts / pictures showing bullet expansion vs speed and your comparison may exist.

My opinion - I think these bullets have optimal expansion speeds and RN is lower so think about your typical shot range and the speed its going. An example is magnums are designed to work at longer ranges where slow rifles work better at chip shot range.

And to give you an all out opinion... I thought my 308 with 180 grain round nose worked the best at close range compared to spire points. You can't find them as easily now so I use 150 grain spire.
People may argue that 3030's would work as good, but its now a speed & energy comparison.

"RN is lower" what?
Do you mean the RN expansion happens at slower velocities??
Then at the same impact velocity it would expand quicker?

I recently heard the argument that since the contact surface area of the RN was greater, the energy imparted at contract was more spread out and dispersed so the RN expanded less.

On deer-sized game? The effects of one over the other is going to be negligible. The difference is going to be in the BC, and that is only going to manifest itself at considerable distance. At normal deer hunting ranges, bullet shape will be an insignificant factor. If all things could be held to be equal, both rounds would do their job equally well.

My 35 Whelen whitetail load was a Rem 200 grain PSPCL, and I switched to a SPCL after having a less-than-stellar performance on the first deer I hit. This may seem a bit hypocritical, but the folks here on the 'Fire that pointed me towards the rounded-nosed version of the same bullet said the 200 grain PSPCL's had a stiffer jacket than the SPCL. I switched and have not had a problem since.

June 1998 issue of Handloader magazine (Gary Sciuchetti, "The Best Hunting Bullet", No. 193, pp. 40 - 44).
The RN Remington 180 vs the non PSP VERSION of the core-lok seemed like it expanded at the same rates but ended at a higher speed and penetrated further.

My pard and I have shot several deer with Horn 154 RN out of 7-08's and the results have been nothing less than spectacular. A few have been shoulder hits, and a couple were frontal chest hit. All have exited so I don't have a bullet to show you.

I have no doubts the 154 Horn Spire would have produced the same results. At .280 Rem, 7x57 or 7-08 typical velocities I consider either of the 154 Horn bullets a "premium" and a very close second to the 150 Nos Partition in on game performance.

If you look at enough pictures on the internet, I think you will see a larger frontal diameter on recovered 154's RN's from water jugs. The game animals you will shoot with either won't be able to tell the difference....

+1

I think for deer hunting at ranges of less than 300 yards, round nose bullets are terrific. We have shot a barn full of Whitetails with Sierra Pro-Hunter RN bullets in 243's to 30-06's over the years. Fail proof.............

A larger front meplat (such as on the 64 grain Nosler BSB) seems to give a little more WHOOMPUM than a spitzer, IMO. I expect that it opens up slightly quicker and wider due to more frontal resistance.

I don't think it would be possible to make a comparison. The round nose usually have more lead exposed and the spitzers are usually designed for higher velocities.

But for short range use and moderate velocities the round nose certainly are consistent. The moderate velocity and blunt shape may improve straight line penetration.

I used a lot of RN bullets when i bought in to the brush busting myth. They worked so well I continued to use them even after the myth was busted.

I can not tell you if the RN is better than a SP but can say that the 154 Hornady RN at 7mm-08 velocities is devasting and as CLB said, as I am his hunting partner after shooting several deer with them, have not caught one yet. Besides that, at the ranges we hunt, this bullet is super accurate out of our guns. Stretch it out to 300 yds+, then go to a spitzer or bt spitzer.

Is that chart viewable in detail?
I have a large laminated version on my loading room wall.
in the hornady and Remington categories there are RN and SP comparisons.
The RN SEEMS to expand very quick at 300 magnum velocities and moderately at 06 <100 velocities. In 308 0-200 velocities they act, ALMOST like controlled expanding bullets as the noise broadens but the majority if the projectile remaining unaffected and penetration being high..17-19".