I hope this brings some clarity to the argument.
Yes, that's the article I found. It's the one which repeats a claim that the Minie bullet had a "vastly increased" striking power, resulting in more serious wounds.
That is not what I am talking about. The round ball of a smoothbore tends to mushroom on impact and remain intact, causing a single wound path through the body -- which the higher velocity tends to make more likely. The Minie bullet is conical. It is moving a bit slower, but the bullet tends to tumble after impact, creating an erratic course thought the body and the bullet has a greater tendency to fragment, causing multiple wound paths through the body. The slower velocity actually makes it cause more harm. As I said, counter-logical, but still true.
So, to be clear, is the argument that the Minie ball fragments and so causes multiple wound paths, while the smoothbore passes through the body and thus delivers less energy to the wound?
The erratic path shouldn't actually affect anything since it could swerve "away from" a dangerous point as often as "onto" one.
As it happens, we do have some useful information at Inkerman.
At Inkerman, the British expended 199,820 rounds of small arms ammunition (176,670 Minie balls and 23,150 smoothbore balls), and 2,066 artillery rounds, and inflicted the best part of 11,959 casualties* (from which those inflicted by the French 7e Legere and their 2 engaged batteries should be deducted), i.e. 1 hit per 16.7 small arms rounds expended. Of those wounded, it was found that 91% had been hit by Minie balls.
* NB: Russian casualty reports exclude minor wounds.
Now, obviously there is a little difficulty here in disambiguating the data, but of the small arms rounds fired 88% were Minie and they produced 91% of the wounds (irrespective of those killed). If the smoothbore were more likely to produce wounds and less likely to produce fatal injuries, we should expect that the smoothbore would be overrepresented in the wounded, but this is mathematically impossible (though unfortunately in this case we can't disambiguate misses).
I've also looked at the army medical history records, from the period when smoothbores and minie balls were both in use:
Charles Greenleaf (on the Peninsula):
I assisted Surgeon Milhau, U. S. A, medical
director of General Heintzelman's Corps, to receive the wounded at that point. Nearly all were wounded in the upper portion
of the body by the minie balls and fragments of shells
H.E.Brown (on the Peninsula)
The only articles deficient were chloroform and ether; and this, I
think, was not due to any neglect, but to the fact of the unusually large number of wounded, we having to attend not only to
those of our own division, but to all of those wounded in the battle of May 31st, the ground of which was occupied by the enemy
until Saturday afternoon. Nearly all of our men brought in were wounded with the conoidal or minie ball. I saw but one by
cannon or round balls. There was one case of bayonet wound, and this man had two wounds from gunshot and five bayonet
wounds; and these last, he asserted, he received while lying on the field, after being wounded. The rebels captured by us were
wounded with the bayonet, with round ball and buck shot, and with the conoidal ball, and some few had shell wounds, the
conoidal ball, however, preponderating.
Medical director McParlin (on the Northern Virginia Campaign):
The wounded, I may say, were not sufferers
to any extent from vicissitudes of weather. It was a fine season, with frequent midsummer rains. The wounds inflicted in the
various actions were, I believe, principally from minie balls and shell at ordinary range.
Philip Adolphus, on the Chancellorsville campaign:
Indeed, every engagement demonstrates an abundant supply of superior quality
of all arms, when compared with earlier contests. Very few round balta, buckshot and slugs are now employed by the rebels,
whilst, at the battle of Winchester, a large part of their ammunition was of the kind last mentioned.
G.G.Shumard, on Perryville:
The battle of Perryville was fought on October 8, 18C2,
and for the number actually engaged, may well be considered one of the bloodiest and most severely contested of the war.
The weapons employed by the enemy consisted of Minie, Enfield, and Springfield rifles, and common muskets. Most of the
wounds inflicted were from conical balls, and were large and severe, the balls appearing to have entered the body sideways,
revolving.
Ira Russell on Prarie Grove:
The troops of
the enemy were armed with Enfield rifles, Austrian muskets, shot guns, and a few squirrel rifles. Most of the severer wounds
were caused by conical balls ; but the nearness of the contending forces at times gave to round balls nearly the same penetrating
and crushing effect. I saw conical balls of three sizes ; grape, round shot, round muBket bullets of at least two sizes, and
buckshot.
CFH Campbell, on First Bull Run:
The wounds
were all from gunshot, and principally of the lower extremities, produced by round musket balls, buckshot, and, in one or two
instances, bv sphero-conical balls, fired at a range of from sixty to two hundred or three hundred yards. These wounds were,
in no instance which presented itself to the writer, of a necessarily fetal character.
WC Spencer, on the Peninsula:
The wounded men were removed from the field by an
organized body of litter-bearers and ambulances. The men were exposed to both artillery and musketry fire at short range, and the majority of the wounds were produced by conical balls; few, by the round ball or buckshot.
DW Hand, on the Peninsula:
My brigade of four regiments, and at that time about two thousand
seven hundred strong, lost forty-four killed and two hundred wounded. They were exposed to musketry fire at short
range, and were mainly injured by conical balls.
John A. Lidell, on Seven Pines:
I think General
Richardson's division suffered a loss of about five hundred killed and wounded. The wounds were inflicted mainly by the old
round bullet and buckshot cartridge. There was, however, a goodly number of wounds made by the conical bullet; but the
majority were inflicted by the former missiles.
Obviously the OCR is sub-par, here, but in most cases there is a pattern where the wounds seen are more often minie balls than smoothbore. This is all in the period when smoothbores and rifle-muskets were in mixed use - the reason I've included Adolphus is because he's noting the point when the transition to rifle-muskets is essentially complete.
As noted, what we should
expect if the minie ball is more lethal is that men struck in the torso tend to survive wounds when hit with smoothbores that would kill them with the Minie ball. The anecdotal evidence does not support this strongly, and we would need to look at some kind of statistical evidence to confirm the case.
Is there such a statistical analysis out there, either way? For example, if we had wound locations and projectile type either from a given battle or summed across the war.