One enjoys much ever "Re-Invention of Wheel". No-One it seems recalls historically abysmal results of Fully-Enveloped Projectiles.
In 6.35mm as well, 7.65mm One does not "Via Expansion" tissue disruption to make, rather by impact velocity and Projectile of flat Meplat.
Quite usually, (In reality) such Projectiles as "Silvertips" will NOT in tissue deform/expand. Yet desirable over Fully-Enveloped.
Had this discussion with Joe Zambone when I the initial Research&Development upon what was later known as "Mag-Safe" Ammunition completed.
"Simply insufficiant Mass inherent in 6.35mm for deforming/fragmenting Projectiles efficacy retaining".
In fairness to Him, MOST "Defence Projectiles" are into such media as "Ballistic Water Bottles" expended. Gives Folk something to "Oh and Ah" about.
As to "Penetration", have this discussion with several "Zealots" had. If "Massive Penetration" in 19th and 20th Centuries such efficacy had, why then was any effort in developing deforming Projectiles expended?"
Along with "Joke Article" RE: "Ballistic Yoghurt", I did another Article write in jest; "12-18 Inches of Penetration; By Anyone Other Than Wife, Girlfriend Or Significant Other Required?"
This in response to "No Answer Forthcoming" in respect to question; "Will everyone who's wounds did NOT 12.0" penetrate now from Grave rise?"
"Penetration-Pundits" seem unable to rationalise why "Under-Penetrating Projectiles" effectively perform.
Perhaps as "Real-World", No "Deer" ever a Ballistics-Table read to be impressed, nor has anyone (Of My Knowledge) yet measured "Wound-Depth" in own Body only to then Sneer at Shooter; "Your Projectile Underpenetrated, I Taunt You!"
There ARE effective designs for 6.35/7.65mm as well, 9mmK (.380), pity is, not commercially extant!