Official MM Firearms Thread

[ScottyB]

Haven't you guys seen the Journalist's guide to firearm identification?

got it hanging in my office...people love it

[BLINGMW]

I'm quite surprised that a falling bullet would have enough energy to tear through a roof, let alone a roof and then a head. :dunno: That's like, wow, a sign* or something when you're IN CHURCH.... Sad though

I wouldn't be too upset about the "AK-47" thing though. I mean, this ballistics expert apparently found it's a 7.62x39 round, probably said something like "this probably came from an AK47", and that probably (I could be wrong) is the most prevalent rifle that fires it.... so... that's not really an inaccurate statement to run with.

*The sign being, there is no god, poor little family, and you probably shouldn't go back to church.

[CaptainHenreh]

Yeah, if they found a .312 diameter bullet they could have determined that it came from a 7.62X39 or X54r rifle, and while it's not exactly fair to say "ZOMG AK47" it's not an unreasonable conclusion since there are approximately 1 zillion kalashinkovs lying around the planet. Hell, probably that many lying around Georgia.

And Chan, it's not that surprising. You have to keep in mind, the bullet isn't "falling", it's following a ballistic path, so it's still has ALOT of energy, and with a non expanding bullet (which if it was a AK is like 99% likely) a ceiling isn't likely to provide much resistance, to be honest.

Also regarding the Ruger Mini-14, I give you the Ruger Mini-14 Shooter's Diagnostic Chart:

[Mike]

And Chan, it's not that surprising. You have to keep in mind, the bullet isn't "falling", it's following a ballistic path, so it's still has ALOT of energy, and with a non expanding bullet (which if it was a AK is like 99% likely) a ceiling isn't likely to provide much resistance, to be honest.

Chan, weren't you ISAT? I sucked at the ISAT math classes because they required you to do homework, but I'm pretty certain I remember doing some velocity blah blah blah equation and finding a bullet falls at [nearly] the exact same speed it went up. That's why these fucking idiots you see firing off guns into the air in foreign countries during celebrations are such... idiots... bullets are falling all over the place at deadly rates of speed.

[CaptainHenreh]

Well, fired *straight* up, a bullet expends all of it's energy going up, and then on it's return trip it will eventually reach terminal velocity which may or may not be lethal (but will definitely not be the same speed at which it went up.)

On a ballistic arc, energy from the initial powder burn is retained on the way "down". The amount of energy retained has to do with alot of factors ("viscosity" of the air, the ballistic coefficient of the projectile) but even with a pretty dramatic "arc" there's plenty of energy left to kill you with. (depending)

[Ken]

Well, fired *straight* up, a bullet expends all of it's energy going up, and then on it's return trip it will eventually reach terminal velocity which may or may not be lethal (but will definitely not be the same speed at which it went up.)

On a ballistic arc, energy from the initial powder burn is retained on the way "down". The amount of energy retained has to do with alot of factors ("viscosity" of the air, the ballistic coefficient of the projectile) but even with a pretty dramatic "arc" there's plenty of energy left to kill you with. (depending)

This. We mostly ignore those factors in ISAT math, because well, it's easier lol and for most purposes accurate enough.

[BLINGMW]

well... I WAS going to do some math myself, but this is easier:

http://www.handloads.com/calc/

I didn't spend a whole lot of time validating the calculator, but the velocity and energy seem reasonable I guess. Using these values from the story and what we know:

# Velocity = 2300 ft/sec
# Bullet Wt = 125 grains
# Sight in at = 100 yards
# Ball Coef = calculated as .164 from a .33in, 125g, round nose bullet
# Sight Ht. = 0.5 in
# Intervals = 100 yards
# Mx. Range = 1000 yards (~.5 miles)
# Muz Elv = 30 deg
# Temp = 65F
# Altitude = 1043ft for Decatur GA
# Wind mph = 0
# Wind dir = 0

Starting bullet energy is 1468 ftlbs. After 1000 yards, it's slowed to 638ft/sec, which is higher than terminal velocity (300-400 ft/sec range acording to the internets) so it's still got some good forward motion. Anyway, it's 113 ftlbs of energy now. About the same energy as a cheap, target load .22 at close range. So, yes, that can kill you. And after passing through the church roof, well apparently it was still enough even though the 7.62 has to cut a pretty big hole in the roof compared to a .22. But a little thicker roof, or any peice of a truss, or a little thicker head, and forget it.

So I guess my initial, estimation based response of surprise wasn't too silly. The numbers also seem to support why the expert knew it wasn't likely 2-3 miles away. At whatever arc would maximize distance, the bullet would have had maybe half the energy and not made it through the roof.

[Jeff]

Could it have passed though a window? Does the article say it actually came though the roof? Also, a baby or toddler's skull is much softer than an adult so that plays into how fast it would need to be going.

[Mike]

OMG Chan is a forensic expert now! I love the Internets!!!

[CaptainHenreh]

We were able to reproduce the rifling marks on the bullet from the entry point in the skull and match it to our FBIATF Forensic Ballistic Database and found that....

It was Col. Morrison in the Billiard Room with the Kalashnikov!

[Jeff]

HAHAHAHAHAHA......sorta like Lil' Jon the Baptist.....BAWHAHAHAHAHAH

[BLINGMW]

OMG Chan is a forensic expert now! I love the Internets!!!

I know right! :lol: I should put this on my resume!

[Mike]

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[Goodspeed]

This'll probably get flamed, but its just so badass. I want one.

[REED]

http://www.yourdailymedia.com/media/1231...unman_Ever

that was awesome, I would love to see him do that on that newish show.
ya know the one with all the high speed film stuff,

[eurospeed951]

Some new toys.

[CaptainHenreh]

What's the second toy?
You know H&K hates you and thinks you suck, right?

[ScottyB]

i have that exact model airsoft gun :thumbup:

[eurospeed951]

What's the second toy?
You know H&K hates you and thinks you suck, right?

I know. That's why I just picked this up last weekend even though I ordered it in October :roll:
Still getting use to the LEM trigger on it, but I love everything else including the night sights.

The second one is a Ruger SR9 with a Viridian Laser.

[JustinG]

ok need some help finding something first and for most this will not turn into a 20ga vs 12ga argument....Jeff. Gun in question is the 870 20 ga Youth model i have had since i was like 12, it was my second gun after a .22 LR. Walked into my Grandparents house and the box was sitting there on his desk. He told me to open it and i thought it was the coolest thing i had ever seen. Then he said it was mine. So many 2 liter bottles full of water suffered that day. Anyways. Dual Purpose HD and Sporting clays. Looking for an AR type adjustable stock, and will need to convert the foreend to synthetic black as well but those i can find easy. I can find them on the interwebs but i didnt know if anyone on here had any sort of brand recommendations or input. I saw one at the gun show in richmond but didnt pick it up, wish i had. I may add a extension tube if i can find one as well.