Evening Gunlopnik

"Snuze: Needs another Swede" (markg)
05/21/2015 at 21:45 • Filed to: None

Just in case you ever wanted see how an AK works in slow motion.

DISCUSSION (25)

For Sweden > Snuze: Needs another Swede
05/21/2015 at 21:46

Anyone else suddenly want to reeducate some dissidents?

Sweet Trav > Snuze: Needs another Swede
05/21/2015 at 21:51

M1A’s are cooler and better guns

ZweiDeutschesAutos > Snuze: Needs another Swede
05/21/2015 at 21:55

Is it just me or are the tolerances on that pretty shabby?!

HammerheadFistpunch > Snuze: Needs another Swede
05/21/2015 at 22:11

Either I know very little about ballistics (true) or there is a good reason that nobody can shoot James bond, in every shot with the bullet it already has wobble and isn’t flying strait.

Snuze: Needs another Swede > HammerheadFistpunch
05/21/2015 at 23:49

Its called “Fleet Yaw” and believe it or not it’s only something thats been recently understood. Anecdotal evidence has supported it for years but only with the advent of high speed cameras has it been consistently documented.

Basically as the bullet leaves the barrel it develops a small wobble. However the gyroscopic forces eventually even it out. Theres a lot of factors that affect the severity of it and how long it taken for the bullet to “go to sleep.” My understanding is that short, fat, lower velocity bullets, high sectional density bullets such as handgun rounds are less susceptible to the effect and stabilize very quickly. Long, narrow, high velocity rifle rounds are more susceptible and take longer to settle down. Of course all the usual players affect this as well - establishing the ideal bullet rpm, a proper muzzle crown, etc.

This was observed almost 100 years ago - British riflemen using the .303 Enfields used to get beaten badly in short range 100 yard competitions, but the same shooters, guns, and ammo would excel at 300 yards. As an Enfield shooter myself, I can attest to this. On open sights I can shoot basically the same groups at 100 yards as I can at 200 yards.

More evidence comes from more recent conflicts. The M1 .30 caliber Carbine received mixed reviews, with some units lauding its stopping power and others reporting the need for multiple shots on target to stop and enemy. Soldiers in Vietnam reported that the M16’s 5.56mm round could be deflected by foliage. And like the M1 above, recent cave fighting in Afghanistan has led to similar mixed reports of terminal effectiveness.

This led to a long term Army study which finally documented and characterized the effects of “Fleet Yaw.” What they found was that at close ranges (less than 50 yards for a 14.5” barrel M4 firing the 62gr. M855 round) the fleet yaw is so pronounced it *can* cause the bullet to enter the target at a highly oblique angle. In target shooting its called “key holeing”.

Because expanding bullets are banned by the Geneva Convention, modern bullets are designed to deform and tumble in the target, dumping its energy in a short distance . This is done by creating bullets with hollow, or low density noses. If the bullet hits the target at an oblique angle, it will not properly deform, which means no tumble and relatively little energy transfer.

Because the fleet yaw is governed by a lot of variables and the actual orientation of the bullet to target is subject to the rotation, range, and yaw effects, its been found that its pretty mich a toss up at short ranges as to whether or not the bullet strikes the target at an appropriate angle. Hence the wide variance in the reports of terminal effectiveness.

HammerheadFistpunch > Snuze: Needs another Swede
05/21/2015 at 23:55

Killer read, thanks! I love learning new stuffs.

Snuze: Needs another Swede > ZweiDeutschesAutos
05/21/2015 at 23:57

They are complete shit. Have you ever held an AK or disassembled one? They are made mostly from metal stampings and rivets. They are dirt cheap and simple to make. Reliability is fantastic, at tthe expense of accuracy.

Im convinced you could take an AK, pour honey inside it, bury it in sand, take it out, chop a large tree down with it - and I don’t mean shoot it down, I mean bludgeon the tree trunk with any part of the gun you want, until you’ve hacked away enough wood for it to fall - and then load up a 75 round drum of the shittiest steel cased Russian ammo you can find, and it would work flawlessly.

Snuze: Needs another Swede > Sweet Trav
05/22/2015 at 00:01

Not sure that I agree with you there. Maybe a factual comparison is in order.

AK Pros:

Dirt cheap

Simple

Can work with parts missing

Makes a great hammer, axe, or pry bar

M1A Pros:

Pretty

More powerful

Capable of hitting things you aim at, from significant distances

Snuze: Needs another Swede > HammerheadFistpunch
05/22/2015 at 00:04

You’re welcome. I love shooting and ballistics is absolutely fascinating. Alway so much to learn.

HammerheadFistpunch > Snuze: Needs another Swede
05/22/2015 at 00:06

I haven’t shot my guns since I inherited them...i need to.

Snuze: Needs another Swede > HammerheadFistpunch
05/22/2015 at 00:15

Yes you do. Do you mind if I ask what you inherited?

I have a few modern guns like ARs, AKs, etc. But mainly I collect WWII and earlier rifles, and odd military and police pistols. I have a few Enfields, several Swiss Schmidt-Rubin straight pulls, a Mosin Nagant, an 03 Springfield, and quite a few weird handguns.

HammerheadFistpunch > Snuze: Needs another Swede
05/22/2015 at 00:20

nothing fancy, a Smith & Wesson .357 mag long barrel revolver and a lugger .22

Snuze: Needs another Swede > HammerheadFistpunch
05/22/2015 at 00:28

Very nice. I have a Browning .22 I got as a gift from my folks and a Beretta 71 .22 that came from Israel. My dad has a newer S&W 686 Powerport .357 and its real nice. Some of the older Smiths are starting to go up in value though, so Id make sure you know what you have. I’m not really into wheelguns but I do have a Manurhin MR-73 with Trausch target grips, same as used by the French GIGN counterterrorism force.

HammerheadFistpunch > Snuze: Needs another Swede
05/22/2015 at 00:34

This is tangential but I’m actually a direct descendant of Mathew browning, John Browning’s brother and business partner.

Snuze: Needs another Swede > HammerheadFistpunch
05/22/2015 at 00:47

Not tangential at all - I think it’s awesome that you are related. Does your family still have any connection with the company? I love Brownings as well, and I have a 1911, though it’s a Springfield, but its still a Browning design and its fantastic. I also have an FNH manufactured, rare alloy framed Hi-Power thats currently on the work bench for some minor repairs. The Hi-Power is probably my favorite handgun of all time.

I also have an A5 Magnum made in the early 80’s that I shoot trap/skeet/sporting clays with. The A5 was such a technological marvel and probably the best selling semi-automatic shotgun of all time, though it seems to have already faded into obscurity. Its more fiddly than all the modern self compensating gas op guns. But I like that about it. And its crazy long recoil sliding barrel. Its a real beauty and gets so much attention at the gun club. I think its basically the ultimate Jalop shotgun.

HammerheadFistpunch > Snuze: Needs another Swede
05/22/2015 at 01:12

No direct connection no.

Sweet Trav > Snuze: Needs another Swede
05/22/2015 at 07:23

M1a’s are quite durable as well. heavy enough to operate as a hammer or pry bar.

Also 762x39 is a tumbling round, loss in accuracy and loss in lethality. There’s a reason the M14 has been in service in some form since 1959.

if I had to rely on a rifle to protect my life, it’d be an M14.

Snuze: Needs another Swede > Sweet Trav
05/22/2015 at 08:11

All points well taken. The big difference I see is that M14’s are super nice, so I’d feel bad about using it as a hand tool. I’m actually pretty certain the AK was designed as a handtool first, and gun second. As far as rounds, you’re right, the 7.62x39 is inherently not an accurate round, but it does have great short range stopping power. On the other hand, the 7.62x51 is probably the single greatest all-purpose round in existence.

In all seriousness the M14/M1A is a great platform. My father-in-law has one and it is an absolute dream to shoot. I definitely want to get one at some point, although I’m currently sitting on some AR-10 parts that will eventually get built into something.

You can tell a Finn but you can't tell him much > Snuze: Needs another Swede
05/22/2015 at 11:09

It’s amazing how well that functions with major parts missing. Somewhere that I can’t find there is a slomo video of an M4/M16 cutaway being fired. They machined tiny little slots into different areas so you can sort of see how things work.

It always amazes me how much mechanical things deflect when you see them moving in super slow motion. Pretty cool that we have the technology to take pictures fast enough that you can see the bullet fly past the camera.

Snuze: Needs another Swede > You can tell a Finn but you can't tell him much
05/22/2015 at 11:29

Yeah. The top cover doesn’t surprise me too much, it’s not really a structural part in the gun. Although I’d be a little nervous that recoil spring could work loose, it’s only held in under tension. But working without the gas tube? That’s bonkers to me. Although I have more experience with AR’s where getting the right gas pressure, dwell time, etc., is crucial to smooth and reliable operation. AK is like “NFG YOLO!!1!”

High speed photography is amazing. And if you read my response to someone else in this thread, its pretty much the only way we were able to figure out “Fleet Yaw.”

You can tell a Finn but you can't tell him much > Snuze: Needs another Swede
05/22/2015 at 12:04

The tube on an AK is just a guide tube to keep the piston lined up with the cylinder. Still impressive that it works without it. You can see the relief ports right near the back of the front “cylinder”. As soon as the piston clears that the pressure is dumped and the operating rod is running on momentum.

AR gas pressure is all sorts of fun. Things are pretty well settled with .223/5.56, but a couple years ago I built a 6.8SPC for deer hunting. I learned that you don’t buy the super saver PSC bolt carrier if you want a 6.8 to run nice. I had all sorts of fun trying to get it to run reliably, but eventually sorted it to the bolt carrier being “off”. Not sure what was up as that bolt carrier runs fine in my .223, but it is no joy in the 6.8.

Highlander-Datsuns are Forever > Snuze: Needs another Swede
05/26/2015 at 14:21

I got to shoot an AK-47 once and was reasonably terrified how easy it was to shoot accurately at 100 yards with open sites. This one was set up semi-auto and I want to say shot .223 rounds. I do a lot of hunting and just don’t have that much experience with guns that are not designed for hunting animals.

Snuze: Needs another Swede > Highlander-Datsuns are Forever
05/26/2015 at 14:55

What do you define as accurate? I’m just curious because it’s kind of a subjective statement. I have a pretty run of the mill AR that I can maintain about 1 MOA with at 100 yards from a rest, and about 2 standing. I have less trigger time on the AK platform, but best I’ve ever been able to do is about 3 MOA sitting and 4 standing. I’m going this weekend so I’ll try again and see what happens.

Highlander-Datsuns are Forever > Snuze: Needs another Swede
05/26/2015 at 16:28

At 100 yards I think a 3” group is pretty accurate with open sights. With my hunting rifle (.270) I usually check the sights (scope) at 150-200 yards and am getting 1” groups lying down no wind etc... sorry I don’t know all the jargon.

Snuze: Needs another Swede > Highlander-Datsuns are Forever
05/26/2015 at 17:12

No worries. My brother-in-law shoots competitively, so I train with him. He’s still much better than I am, but I’m constantly improving. I’ve picked up the jargon from him, and just reading a lot. MOA is minute of angle, it’s 1” per 100 yards (technically 1.047”). It’s convenient because it’s proportional to distance, so 1 MOA is 1” at 100 yards, 2” at 200 yards, 6” at 600 yards, etc.

That’s some good groupings your getting with your hunting rifle. And more impressive that you’re doing it at 200 yards. I’ve heard the .270 is a nice, flat shooting round. I’ve got a Howa 1500 in .300 Win Mag that shoots about that, or could, if I were a better shot. I’ll put down a few nice shots, right around .5 MOA, and then subconsciously pull the last one and end up with an ugly group.