As a bit of a followup to the PDX1 in 7.62x39 test, I decided to bring just the random, cheap, steel cased FMJ that's probably loaded into the vast majority of AK and SKS magazines out there...
...in the world. The goal here was to get a look at the seemingly legendary threat stopping potential of the 7.62x39, regardless of bullet design. Grabbed some good ole Tulammo I have hoarded up for this, my primary "battle rifle" and headed out to do some shooting!
...in the world. The goal here was to get a look at the seemingly legendary threat stopping potential of the 7.62x39, regardless of bullet design. Grabbed some good ole Tulammo I have hoarded up for this, my primary "battle rifle" and headed out to do some shooting!
Here are my personal notes and thoughts as I watch the completed and uploaded video for the first time through.
:10 Sun and wind were big issues again for us. Tried to shoot the video without my sunglasses on for the sake of eye contact with you, the viewer, and just couldn't handle it.
:15 The wind was huge again too, we did several re-takes on clips due to wind picking up, but it still was incredibly frustrating. Hopefully we can get a little income flowing to allow the channel to pay for a new camera with a shielded mic!
:34 (From Jackie Brown) "AK-47. The very best there is. When you absolutely, positively got to
kill every mother****** in the room, accept no substitutes."
1:00 The point was not to look at Tulammo in particular, but just a cheap FMJ in general. Hence not bothering to name it.
2:47 Remembered to account for my sight height over bore this time... kept the shot centered instead of hitting low.
3:22 I've heard that water penetration is about equivalent to 2x gel penetration, hence my estimated penetration guess including the water, but not an exact science.
3:40 One of the evidences of the bullet yawing that I talk about later, flat sides only logically would come from it passing sideways through the gel when you combine that with the look of the temporary cavity cracking marks.
4:59 The single, diagonal expansion crack would also point towards the bullet yawing in that direction, hence releasing energy in more of a line, instead of the circular splayed expansion damage you see in a consistently expanding bullet.
5:30 Seeing the extra damage showing up so far back in the block is what finally clued me into the yawing effect. It generally takes some distance for the clean spiraling bullet to lose it's momentum and start to waiver.
7:30 The instant energy dump in the first few inches is ideal to stop a bad guy, as it causes the kind of damage needed to convince the brain that the body needs to stop, but then doesn't have the "long" energy to carry it out the rear of a threat with significant power.
7:45 The other reason being it's incredible ability to NOT quit functioning.
8:20 Is this mention of the blog what brought you here?
Our QA section consists just of questions from "Rob" in Texas. Mrs. EDG has been crashing out early with her pregnancy nearing it's close, and that's when I do all my blog/video work! So no chance to get her thoughts.
"Rob" in Texas:
Q Why did you expect the bullet to pass right through? (With Rob's question in mind, I answered some of this in the time-stamped notes, but I'll take an organized crack at it here)
A The copper jacket on a bullet is much harder than the lead it contains, so instead of "smooshing" out and dumping the energy quickly, I expected to hard bullet to maintain a straight path. That would have meant the pointed nose of the bullet was leading the way, and with the relatively soft gelatin providing little resistance, I thought it would head right out to the slope we shoot into.
Q So why didn't it do what you were expecting?
A Well, I was aware of the yawing effect that happens at times with FMJ rounds, but my impression was that it happened more in the 5.45x39 round than the 7.62. So when the yawing started maybe 6 inches in or so (evidenced by the flattened bullet and kind of "line" effect of the temporary damage cavity), the sideways bullet of course has much more resistance to passing through the gel than the point, meaning more energy is transferred to the target instead of being carried on out the back.
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