guess MY pics are gonna be a while yet . i thought i'd be doing them already but , no . and i lost the neat russian language website with the illustrated AP bullets . i'll find it .
well , the commercial FMJBTs
ok now , having seen the internals of sectioned bullets and the x-rays of the steelcore military rounds recoverd from jello , note the WHITE in the x-ray shows SPACE . the dark , LEAD or STEEL .
now , take away the steelcore , which is stiff and cannot flow and replace it with soft lead . what do you think happens to the WHOLE leadcore on impact with water , swinesflesh or jello now ?
because the lead HAS SOMEWHERE TO FLOW INTO , it can and will . unlike a normal 'unitized' bullet that has to bend the whole bullet , jacket and all , the SPACE gives the lead a place go besides just squeezing out the base . i dont think lead is subject to any fluid compression at these energy levels .
BUT , its the MIGRATION OF THE SPACE that causes these commercial , leadcore FMJBTs to STAY SIDEWAYS AT THE FIRST 90DEG. YAW CYCLE .
just like normal 'unitized' bullets that try to turn (yaw) to base (weight) forward stablized flight through a semi-fluid media , the improved tipspace bullets ALSO turns to weight forward flight but , as that occurs , nearing 90DEG. through (media) , forces build from almost nothing pointfirst to enough force to cause a large temporary cavity in the media(s) . this represents decelleration or G-Forces , enough to cause the lead to flow into the jacket hemisphere faceing impact , just like with the 7N6 bullets in the x-ray
and ,
the SPACE to flow into the hemisphere AWAY from 90DEG. impact .
the bullet now continues , weight forward , just like previous generations of spitzer rifle bullets only, for these IMPROVED' types , weight forward now means SIDEWAYS . the spin now converts from AXLE to RADIAL . the original center of rotation the bullet was spinning on is gone . the spin has to go somewhere so original twist rate being expressed as , a prop through water .
of course , in a PERFECTLY UNIFORM media you get PERFECTLY UNIFORM sideways RESULTS . striking dense wood , hard packed dirt or bone pointfirst causes the core to ram up into the tip , making a TIP HEAVY bullet . if there is LITTLE OR NO RESISTANCE to forward motion at the 90DEG. yaw angle , no lead flow can take place . it continues around to BASE FIRST stability . this could happen traversing the upper chest through a lung .
at whatever angle the bullet finds resistance sufficient to flow its core at sufficiant impact , thats how the lead will orient within the jacket . but for the most part it means PROFILE PENETRATION of flesh .
these bullets , the 5.45x39 Wolf and Barnaul FMJBTs and the 762x39 Wolf and GoldenTiger FMJBTs are 90DEG by 4.5" penetration depth in water @100M . 90DEG by 3.5" penetration depth at 500M . they will begin the yaw cycle(s) penetrating only enough water to IMMERSE themselves in , about an inch and a half or so .
the ULYANOVSK 8m1 nipple and 8M2 FMJFB , along with the GoldenTiger 5.45x39 FMJ , have more of an EXTENDED DWELL TIME while sideways rather than perfect PROFILE PENETRATION . SLOW YAW . the effect is nearly the same as the others but there is less SPACE to migrate .
WATER compares 1 to 1 for FMJ DEPTH OF PENETRATION TO 90DEG YAW with 10% gelitan . it compares 1 to 1 for all the famous/infamous FMJ spitzer bullets such as 303 MK7 , 762x51 M80 , 762x39 M43 and M67 , etc.
no applause please , just throw flowers :bow: