Posting this again, shooting at sub sonic speeds this clearly shows the superior ballistics of the 240 SMK over a 230 gr .45. Not to mention that the 300 BO is Capable of shooting this bullet and many others at super sonic speeds. Can your 45 acp carbine do that? Certainly not as it needs a carbine length barrel just to achieve 1100 fps.
Ok. I'm trying to make this the last time anyone will need to explain you the basics, so read carefully. Repeat if needed.
External ballistics are one thing. The bullet flies in an arch trajectory, dropping more and more over distance. Yippee. Gravity at work! The bullet and target are supposed to meet at some point and with any subsonic bullet ranging the distance is paramount in order for that to happen. It's not difficult unless you expect a laser-straight trajectory and have no idea of bullet drop at any given distance of the round you use for hunting, in which case you shouldn't be hunting but at the range figuring out this basic factor.
Following me so far? Good.
Next, if you've followed The Successful Hunter's Playbook to the letter, the bullet impacts the game animal, which we're going to call the target. In a perfect world the bullet goes through the heart, causing a massive drop of blood pressure, depriving the brain of the target of the flow of oxygenated blood, causing the target to lose consciousness in a fraction of a second.
However, we don't live in a perfect world. There are a number of factors like human error, which cause the impact point to deviate from ideal. In that case, the bullet usually goes through lungs and soft tissue surrounding it. The hit is fatal, but instead of collapsing, the target takes off. Usually at a great speed. And runs. And runs. And runs, until the loss of blood via internal and/or external bleeding is too much for the central nervous system to continue operating. At that point the target loses consciousness and collapses.
The rate of bleeding, hemorrhaging, is highly dependent on the wound inflicted. It comprises mainly of the permanent wound channel, as - like I mentioned earlier in this thread - hydrodynamic shock by a low velocity bullet is very limited. Flesh, as we know it, is very flexible, especially muscle tissue. The surface area for hemorrhaging is determined by the length and diameter of the wound channel, as well as the number and diameter of blood vessels, ideally arteries, that cross paths with it.
A tough, small diameter bullet that has no chance to expand at impact velocity passes through unexpanded. Let's say that the diameter is 0.3" and wound channel length is 12 inches. In that case the surface area of the wound is 22.62 square inches. Fair enough. Considering what I mentioned about the flexibility of tissue, there's a good chance a wound this size will be partially closed by muscles and skin. In that case, hemorrhaging is greatly reduced, much in the same fashion as when pressure is applied on any wound.
You've taken a hunters' first aid class so you know this, don't you? In military training they explained this in a bit more detail but basic principle will do for now. So we go on.
Let's change one variable. The bullet. 0.45" is a good example and as many pistol bullets of that diameter are designed to expand on impact, let's say the wound channel diameter is a still conservative 0.75". We're not shooting Black Talons now, they're collectible and expensive. At the same time, in spite of the bullet being heavier, penetration will be slightly shallower, say 10 inches. What just happened to the wound channel? Its surface area increased over 108%, to 47.12 square inches. On top of that the hole in the skin is 0.45", greatly reducing the probability of flexible tissue preventing hemorrhaging. On the inside in porous lung tissue the hole is 0.75", keeping up massive hemorrhaging to the lungs, reducing blood pressure rapidly, filling the lungs with liquid that prevents oxygen absorbing to the bloodstream effectively drowning the target in its own blood.
This is far, far, FAR more meaningful factor than a tiny, miserable one inch more drop at 150 yards, which by itself is extremely easy to compensate providing that some superhuman hunter actually can place a subsonic bullet in real life hunting situation to the accuracy of an inch at that distance.
This concludes the Real Life Meaning of terminal ballistics vs. in flight external ballistics fresh out of the nearest theoretical benchrest calculator.
I also see you got back to the "capable of shooting this bullet at supersonic speeds" -excuse. So it is. So is .308, which by itself gives a whole new meaning to supersonic compared to anything .300BO will ever be capable of. That doesn't make subsonic .308 rounds any better for hunting than .300BO, which can't hold a candle in all-important terminal ballistics to old, measly .45ACP. Or .45 Colt. Or .44 Special. Or even .38 Special for that matter.
By the way, a long time ago, in early 90's if my memory serves, I came across a couple of boxes of russian 7.62x39 subsonics, loaded with copper plated instead of copper jacketed bullets. They did a marvelous job of expanding on impact at their rated 1050fps velocity, mushrooming to .7" or so. I've tried to get my hands on more of those, even bare bullets would suffice for reloading, but to no avail. Those are by far the only rifle caliber subsonic rounds I've found that actually work by expanding sufficiently, instead of just plowing through tissue punching a hole of a nominal diameter.
If you find similar bullets for your .300BO for reloading, it'll be the first time in this lengthy conversation where it might just be comparable to pistol rounds of similar weight in hunting applications. I already asked a couple of bullet manufacturers about having them made in .308; one of them would but MOQ is a ridiculous 100.000 bullets at $.65 a pop. Until then, there's little point in trying to reinvent the wheel with a new caliber that offers no advantage over established .308 and 7.62x39 subsonics and doesn't come close to the terminal ballistics of a number of pistol rounds.
Any more questions or is this finally clear?
Thank you.