Thanks to Roundball for taking the time to do the wet pack tests.
But the RB vs Bullet discussion always gets lengthy.
The importance of penetration will depend on the situation and the animal be shot.
Since we do not often shoot African Elephant or other heavy game in NA we will limit or discussion to what is likely to be encountered in on this side of the ocean. For example based on historical writings, it takes a 2 or 4 OUNCE RB at 1400 fps or a little more to really equal a 458 or 470 as a "stopper" for African Elephant.
As soon as someone mentions penetration and the RB the poor penetration/sectional density comments begin.
We need to understand that the Rb need not shoot though an Elk's shoulders at 300 yards as a friend did with a 420 grain 45-70 bullet. Or through Bison at 600 as even a heavy bulleted 40-70 will do, I think this is in "Getting a Stand". There is a an account of a 1:20 (about factory standard for the time) alloy 330 grain from a 40-70 SS shooting through a gbear from end to end in one of the hunts that the western photographer LA Huffman participated in. I think its in "Before Barbed Wire".
But shooting elk at 300 yards or Bison at 600 is not relevant its beyond the scope of hunting with the traditional ML hunting rifle. Shooting a Gbear is not something most people here are ever going to be faced with. If so they need a large diameter RB. Or one could set up on a trail someplace with 54 to 69 caliber ML slug gun shooting a bullet weighing 2-4 ounces. One of these will shoot through almost and any land animal from any angle.
A 45 caliber RB with a reasonable charge of powder, say 1/2 ball weight or so, will shoot though an "average" deer's chest cavity on broadside shots to 120 yards or so. A 50 caliber RB will shoot through a Mule deer at 140. *Probably* to 200.
A 350 gr 45-70 will do the same thing with higher exit velocity. A 400 at BP velocities 1250-1350 FPS will probably shoot through a deer endways. I have done this with a 50-70 Gov't with a bullet that closely approximates the "issue" bullet and a 54 percussion Sharps with the "Christmas Tree" bullet.
I have accounts that I consider to be beyond question concerning RB penetration on Canadian moose. If a 54 RB will penetrate to the far side hide of an moose at 175 yards I hardly consider it to be greatly hampered by its lack of section density.
With a soft lead ball the 16 bore rifle will only penetrate 30 odd inches into a deer (after penetrating one of the hardest spots on the animal, the brisket to one side of the windpipe.
I have gotten similar results with a 54 with a head on shot but in this case the deer started to turn as I broke the trigger and the ball struck behind the shoulder at a pretty shallow angle, cut off 2 ribs and was lodged at the far end of the deer. The deer required some followup to bring it to bag but I doubt shooting through another 1/4 or 1/2" at the butt end with a bullet would change this.
This ball weighs about what a medium heavy 45 caliber cartridge bullet does. BUT when IT REACHED THE VITALS it was making a FAR LARGER wound channel that I have EVER seen made with a 40-44-45 or 50 caliber cartridge rifle REGARDLESS of bullet Meplat or alloy or powder charge at the same distance 40-50 yards.
It is a fact, according to all accounts that the 22LR will kill deer with chest shots.
It is a fact the regardless of bullet diameter or shape or impact velocity, within reason for BP, that the deer will run after being shot if its electrical system is not interrupted.
It is a fact that deeper penetration will not necessarily produce a more rapid kill since once it passes from the animal the it does no more harm.
It is a fact that penetration only be ADEQUATE.
It is a fact that a RB if sized properly for the game at hand and of the proper alloy has in the past and still will penetrate adequately to kill any animal on the planet.
A hunting rifle must do several things. It must have sufficient accuracy to place the shot, it must have a flat trajectory to give it the longest possible point blank range, it must penetrate adequately to reach and damage the vital internal organs of the animal being hunted WITH A PROPERLY PLACED SHOT.
Ahh yes shot placement. Now if we expect to shoot a buffalo in the a@@ and want the bullet to penetrate to the chest cavity or beyond we might want to use a 45-100-500 or a 375 H&H with a 300 grain. But shots of this sort are desperation shots and are not recommended.
It is OBVIOUS from both NUMEROUS current and historical accounts that a 1/2 ounce ball will kill almost anything in NA. Do I consider it the best choice to animals over the size of Mule Deer? No. But I don't think a 270 is adequate for Elk either, but don't tell anyone who has killed elk with one this. There is an excellent account of a plains rifle, probably using 1/2 ounce balls killed 2 buffalo in 2 shots at 175 yards in "The Oregon Trail" by Francis Parkman. The buffalo ran off, but they simply rode down the trail they made and found then dead. A little work with a knife and dinner is served.
Comparing the 25 RB with a 22LR is interesting. I KNOW the 22 LR will penetrate to beat the band. My dad carries a 22 LR bullet up near his hip that entered just above the knee penetrated about 20" plus. Had be been alone he would have been found dead. 6" barreled Browning Nomad 22 LR "solid". One shot stop one might say. The 25 RB will not do this. So what? Its meant to shoot small game. It need not penetrate more than 2-4" to do this.
Had I written a comment on the outcome of the 22-25 I would have postulated the exact outcome that Roundball proved in the tests.
A soft lead ball at high velocity will deform and produce a lot of shock. More than a bullet of the same or similar weight will at velocities obtainable with the RB.
Using the heavy bullets true potential and only real advantage over the round ball, range, requires a considerable amount of shooting, a range finder and a table of sight settings for an adjustable sight, the ability to judge the wind and its likely effect of the bullet is desirable as well.
One more thought on "quartering shots" It is possible to kill deer with quartering shots but its a VERY poor idea with anything. If I cannot see to heavily damage the heart, the major arteries or BOTH LUNGS with the shot offered I WILL NOT TAKE IT. Hitting only one lung on a deer or any other animal is INVARIABLY bad. They live a long time and can travel far. Bullet or ball makes no difference. One of the hardest tacking jobs I ever had was a Mulie Buck a client shot through and through at a 45 degree angle but only got 1 lung range under 100, 308 win with a 160-180 gr SP. I doubt it would have been worse with 50-54 RB.
The deer ended up with a running shot from a 45-70 with a 400 Speer as he ran though some trees and a coup de gras before he was anchored.
So unless you have a shot at a something you KNOW is going Boone and Crocket, forget the quartering shot unless you are really good at it and the bullet will track to exactly where you want it.
In guiding people for hire and fun and in some of my own experiences I have been involved in some pretty sorry hunting "experiences". These are ALWAYS the result of poor shot placement so BE VERY CAREFUL of SHOT PLACEMENT. Its FAR more important than the bullet being used.
If you want to of do Texas heart shots don't use a RB, use something with a LONG bullet and a fast twist like a 375 H&H with a 300 gr Core-lokt.
Dan