Not too sure about the "winter uniform" penetration bit. It take a LOT of cotton fabric and goose feathers to stop a bullet, even a pistol-calibre one. I recall that some lads set up cardboard "figures" swathed in half a welfare-store's worth of clothing and with blocks of Ballistic gel behind, to test this story. M-1 Carbine bullets fired at reasonable close-quarter battle ranges, flew through the frocks and drilled deeply into the Gel..
That the soviets were steadily introducing body armour on an expanding scale by the late 1960s was well known.
"SS109" is a composite cored bullet, not unlike a scaled-down .303 Mk7, but with a boat-tail.
The earlier M-193 55gn BTFMJ was designed back i the late 1950s. From a the original 1:14" twist barrels it performed well on "tissue". It would perform a 180 degree turn after striking "muscle tissues" and internal organs and sometimes continue to exit base-first. However, it appears to have been a little "unstable" in flight at Arctic-grade temperatures, so the rifling was adjusted to 1:12" twist. . "Field" results revealed a change in terminal performance; the "more stable' bullet apparently took a little longer to "tumble" in tissue, often drilling all the way through before starting to go wayward.. Sometimes, however, the M-192 bullet would break in two, with both fragments charting completely different courses.
SS109 was derived from a LOT of experiments with "heavier" (up to 77grain) bullets for extended range performance. This was primarily aimed at the new "Light Support Weapon" market.
SS109 and its "clones" will happily stabilize from a 20 inch barrel with a 1:10" twist. So, why the 1:7" twist as "NATO Standard"?
TRACER bullets. to obtain a useful "burn time" fir a tracer bullet in a bullet of such dinky diameter, tha answer was a LONGER bullet. This needed a 1:7" twist to stabilize it.. See also dinky short barrels which produce lower velocoies and thus LOWER spin-rates
At the rotational velocities of the SS109 / M855, etc bullet, terminal ballistics get "interesting". Shortly after impact, the bullet starts to tumble as it transits into a denser medium. The two-piece core can be "disrupted" and the bullet breaks into several separate "fragments. Supplementary, at short-ish ranges, the bullet will still be precessing (wobbling around the nominal trajectory) after it has just left the muzzle. Thus, it will be less-than-perfectly stabilized. We have been down this stability discussion route a few times in the last few years..
One of the reasons for the initial instability is that SS109, like .303Mk 7, is BASE HEAVY.
The old "wisdom" of .303 being "humane" and drilling neat holes is only partly true, and then, only in some circumstances..
If said bullet slips through a light-weight uniform and a few inches of muscle tissue, so far so good.
If the next order of business is striking a material like BONE, things change, rapidly. Think "thigh wounds"; big, meaty target, with a big BONE in the middles. A bullet striking that femur WILL shatter it. Two things:
When that bone is violently broken, the leg ceases to be a "strut", holding up half of the body's weight.two ends of sharp, fractured bone start "wandering about" . Adjacent to said damaged bone is the famous Femoral Artery.. Get a hole in that and you are in serious trouble. Holes may be generated by the slicing action of the shattered bone ends or by "secondary missiles", blasted off the parent bone by the bullet impact.
"Only a flesh wound"? It ain't like he movies .Ask your friendly First-Aid instructor about putting an improvised tourniquet on a "leaking", upper thigh wound.
Mine are not the best, but they are not too bad. I can think of lots of Enfields I'd rather have but instead of constantly striving for more, sometimes it's good to be satisfied with what one has...
So back to the 1941 Win .303. Fired some of the "black label" stuff. Function was fine, if powder a bit dirty (judging from residue and volume of smoke per shot).
Primers are hard and I think this accounts for some leakage. Leakage is annoying and so the ability to screw on a "shooting". bolt head is handy. CCI #34 primers in a few of the cases (with same powder) sealed right as a drum. Cases themselves are right at .060" on the rim, and the cases were not too blown out.
If one doesn't mind the soot then I'd say swapping primers is the ticket and reuse the original powder. But I have the option of 41 gr. of BLC-2.
SS109 bullets will drill through soft tissue MOSTLY without much distrbance.
Ditto the classic .3.3Mk VII.
Hitting anything more robust on the way in or through, changes the game, someshat.
The old M-193 55 gn bullet astabilize OK in the original 1:14" twist M-16.
Sub -optimal stability at sub-zero (C) temperatures (denser air) messed that up. Hence the 1:12" twist..
M-193 causes soft tissue damage partly due to the hydrostatic shock of its velocity on impact. It WILL "tumble" and MAYBE break in two after impact, in a sufficient muscle mass.. Hitting anything harder (bone) on the way through? Instant destabilization with wildly variable results.
Note that the bullet for the Russian 5.45 x 39 7N6 is base heavy and composite cored, just like the SS109 / M855. Funny, that!
The Mk Vll .303 was a masterpiece of "political" bullet engineering. It met he "rules in "form",but the characteristic "tumbling" / bending AFTER impact was a result of careful research into the behaviour of "base-heavy" bullets in live tissue. It was also partially accidental: The initial "spitzer" bullet was about 20 grains lighter and somewhat shorter. The Brits needed a spitzer bullet that would run reliably in a zillion Lee Enfields, so, it had to be a certain overall length, which also helped int the peculiar way the ammo was made (Another story),Hence the "lightweight 'nose filler" that achieved the desired muzzle velocity from the "short" rifle and "by accident" both met the "rules of the game" and produced "interesting" terminal ballistics.
The initial "spitzer" bullet was about 20 grains lighter and somewhat shorter.
The original MKVII bullet was 160 grain, but, as we know evolved into the 174 grain but retaining its original nomenclature.
From the Small Arms Committee meeting minutes 8th December 1909 :
Mine are not the best, but they are not too bad. I can think of lots of Enfields I'd rather have but instead of constantly striving for more, sometimes it's good to be satisfied with what one has...
Originally Posted by scharfschutzen63
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