mosin nagant @ 500 yards

[comblock]

I was checking out YouTube tonight as I am thinking of putting a scout scope on the mosin nagant when I came across this video:



as I was watching the video, I was thinking wow, pretty decent shooting with iron sights at 500 yards. Well, after watching the video for a while, I was starting to wonder why the timing of the sound of the shots and the dirt being thrown up was at the same time. Usually when firing from a longer distance one would see the steel target move or dirt fly up before you hear the target (kind of like a 1/2 -1 sec lag).

However, the shooter of the video states that the camera is 25 yards from the target while the shooter was somewhere 500 yards up a mountain. Ok, so I whip out the calculator and with my google fu looked up that standard
7.62x54r velocity is on average 2600 ft/sec and the speed of sound at about 1126 ft/sec. Now, armed with that knowledge and having barely passed high school and college classical newtonian physics, I calculated that the projectile, being shot from 500 yards(1500 ft) should hit the target/dirt in
0.6 seconds, while the sound of the blast should hit the camera by
1.3 seconds.
So, is this guy bsing or am I mistaken somewhere in my math. What say ye

[emcon5]

Remember, the bullet is losing velocity in flight, so the flight time is actually a little longer. Using the Hornady 174 FMJ for BC numbers (should be close enough for this) and a velocity of 2495 (according to Sportsman's guide) the flight time to 500 yards is ~.74 seconds at sea level.

So it is pretty unlikely that you would hear the report the same time you see the splash.

That being said, it is pretty loud, louder than I would expect at 500 yards. It could be the snap as the bullet passes over the camera. It is still supersonic at that point, an it does sound kind of like what I have heard working in the target pits when supersonic bullets pass over your head.

[comblock]

emcon
ok, makes sense. After putting the external speakers onto the laptop and putting the volume up way high, I can hear a low thump at the end of the high pitch snap.

After all my years of shooting, I have never had the pleasure of a bullet passing overhead (knock on wood).

[Capybara]

I worked targets at a CMP National Match. Man, those bullets are loud a couple of feet over your head. Not pleasant but it was an interesting experience.

[SKSer45]

so mosin nagants can shoot up to a 500 hundred yards? hehe'

but all serious and relating to Capybara, when I was in the Corp we had to work the Pitts like he did in the CMP match. Hearing the round hit the paper is something alright. Really similar to a loud snap/crack and it was quite sharp. That was .223 coming down range too, can certainly see the velocity in that round.

[Josh Smith]

Hello,

Try this:

22RF 50yd Audio Chronograph BETA.xlsx

I made it a couple years back. I don't remember why now; maybe I was bored. Heck, I need to download it to see exactly what program I have it running on!

It figures the average velocity using sound.

Hope this helps!

Josh

[TRAP55]

At 1000yrds it's 1.5 seconds, listin for the "tink" when the bullet hits the plate.

http://www.youtube.com/watch?v=t2M1hC4c0tc

[gun toting monkeyboy]

Yes, they can shoot things at 500 yards. We used to use one to ring gongs at 400, 500, and 600 yards all the time in college.

-Mb