Gif 1: Rifle firing from standing position, outside, narrow angle camera view.
What you see here is spent casings being ejected at such velocity that the low frame rate can’t keep up with the motion. So you see a casin in the center of the image, next frame you see it near the edge, next frame nothing. Also, because of that velocity and narrow camera angle, the casings are being flung well out of the field of view. Most of those are probably going into grass. I wonder if a more thorough examination of the video might show an occasional casing laying in the street or on the sidewalk.
Gif 2: Rifle firing from standing position, inside, narrow angle camera view. (Gee, lots of narrow angle) Firing at corpses.
And what marks are expected? A great big bit of blood splatter? That doesn’t even happen so much with a head shot. See, corpses don’t have blood flowing, and the majority of blood splatter is from blood under pressure given an outlet, so it actually squirts. In a dead body, no heartbeat means no blood pressure, means practically zero blood splatter. Maybe with a higher resolution imagine you’d see something more whatever marks you expected. Even fully zoomed in, 702 x 400 pixels is not as high a resolution as you think.
Gif 3: Shotgun firing from sitting position, inside vehicle, to hell with the camera angle.
Notice the slight darker, bluish tint when you can see through side window as compared to the windshield? How long has that windshield been gone? And just for better understanding, windshields on cars sold in most of the world for the last 2 decades is formed of a sheet of tempered glass. Tempered glass is stronger than most glass, much harder to so much as scratch, but when it does so much as scratch the inner glass under tension from the tempering process quickly spreads the breakage across the entire pane, and the glass shatters into small pebbles with almost no sharp edge. The whole process takes much less than a second. So if the windshield was shot out before, there is no windshield to shoot out now. And again, this low resolution offering wouldn’t see the tiny pebbles of broken glass.
As far as the image of the rifle, it looks to me very much like an AR variant with an unknown stock. What makes me curious, if this is supposed to be some evidence that it’s fake, why not go into more detail, and why the two red circles, each around those white symbols you insist prove it’s fake? I don’t know what the symbol on the left side is, but on the right side is just 14, referring to the white supremacist 14 Words, I’m sure. And if you want to say “unknown stock means it’s fake”, really, do you know each and every possible attachment you can get for each and every firearm ever made? No, you don’t? Then it could be something you just haven’t seen. Maybe, just possibly, there’s an Australian company you haven’t heard of making a stock you haven’t seen … because you’re American, and think the US is all there is?