Great picture of "keyholing"

[esrice]

Saw this on another forum, and just thought it was the perfect picture of 'keyholing'.

Just wanted to share. . .

 

[MeltonLaw]

Ok unless that person is shooting through something they have a problem with their gun or ammo or both. I wonder if they are shooting a load that requires a faster twist barrel. Especially since they are shooting at what seems like 25m and there are over 20 keyholed.

 

[HandK]

Hummm! 7.7 WWII jap wooden bullets?????

 

[jblomenberg16]

Wow!

Says 4 mags / 120 rds rapid fire, so I'm thinking AR or AK. Look like really long key holes, suggesting a really long bullet that needs a fast twist like Melton mentioned...wonder if he was shooting some new reloads?

Also, says something about muzzle brake attached...maybe a few struck the brake?

 

[esrice]

It was an AK Polish Tantal, if that helps you guys.

 

[rockydog]

I think when they finished shooting, someone picked up a sling shot and finally put those steel Wolf cases to good use

 

[DHolder]

I've never seen keyholeing so obvious, usualy just elongated?

 

[sloughfoot]

I've never seen keyholeing so obvious, usualy just elongated?

I have. Sometimes 75 BTHP out of a 9 twist AR15 barrel will show the full profile of the bullet at 25 yards. 8 twist clears that up pronto.

69's are OK with the 9 twist....

 

[Mr.Lubie]

Wow.Thanks for posting the pic.never saw it that clear before

 

[DHolder]

Would like to know if they were reloads, and if they all came out of the same batch or if they happened over the whole course of fire?

 

[shooter521]

Would like to know if they were reloads, and if they all came out of the same batch or if they happened over the whole course of fire?

The initial run of Century-built Polish Tantals used a barrel built from a .223 blank rather than one designed for 5.45x39. Thus, the bore was slightly oversized and the twist rate was not correct for the caliber. The guns would throw keyholes with mil-surp 7n6 ammo, especially once the barrel heated up. Often, the same guns would shoot commercial ammo just fine - especially the 70gr Uly stuff, which, with its longer bullet, was more compatible with the .223 rifling twist.

Century took a lot of grief over this issue, and switched to using real 5.45x39 barrels on subsequent production runs, eliminating the problem. To this day, however, a lot of people refuse to buy a CAI Tantal on the secondhand market, fearing it might be one of the early guns.

 

[TheGhostRider]

I owned a Rockola .30 cal carbine some years ago that produced a wonderful keyhole pattern at 25 yards. Poor old thing was shot out but reliable in function.......
Too bad I couldn't hit anything!
I regrettably sold it... now I wish I had it back!

 

[BE Mike]

The initial run of Century-built Polish Tantals used a barrel built from a .223 blank rather than one designed for 5.45x39. Thus, the bore was slightly oversized and the twist rate was not correct for the caliber. The guns would throw keyholes with mil-surp 7n6 ammo, especially once the barrel heated up. Often, the same guns would shoot commercial ammo just fine - especially the 70gr Uly stuff, which, with its longer bullet, was more compatible with the .223 rifling twist.

Century took a lot of grief over this issue, and switched to using real 5.45x39 barrels on subsequent production runs, eliminating the problem. To this day, however, a lot of people refuse to buy a CAI Tantal on the secondhand market, fearing it might be one of the early guns.

Ah, another good reason (I have others) never to own anything marketed by Century Arms! Never owned a CA product and never will. EAA is also on my personal blacklist.

 

[j706]

What are the chances of so many tumbling bullets hitting exactly side ways so many times? Seems fishy to me.

 

[qwkdrwmgw]

What are the chances of so many tumbling bullets hitting exactly side ways so many times? Seems fishy to me.

I think the guy got ahold of his wifes scrapbook punches and went to town on the target

 

[Litlratt]

It would be more believable if it wasn't taped to a fresh backer.

 

[hornadylnl]

It would be more believable if it wasn't taped to a fresh backer.

That's what I was thinking. No holes in the cardboard.

 

[CountryBoy19]

What are the chances of so many tumbling bullets hitting exactly side ways so many times? Seems fishy to me.

I don't think so. If you look closely there are a few that aren't exactly sideways. I think this is completely plausible.

Also to add to that, if a bullet is really unstable, it will tumble at almost the exact same rate every time. This means that at the right range, it will be VERY obvious (as the photo shows) and all the hits will be almost exactly alike (although oriented in different directions).

This doesn't go for bullets that are on the verge of stability though because slight velocity differences will cause some to tumble immediately upon exit, and some further down range (say 3 feet, or more, out of the muzzle). This will yield differing rates of tumble, and differ places where they impact sideways.

I believe this is a classic example of the first case where the bullets are completely unstable, and the target just happened to be at the proper range to show it so well.

 

[Srtsi4wd]

You would see sellers on GunBroker putting a 5.45 round in the barrel end to show that the barrel is correct. Dont know how well that works but it is/was pretty prevalent.

When I was putting my vz58 together I considered doing a Tantal build and did some looking around. The problem is legit and I saw many examples posted just like the one in the OP.

IMHO, the AK was designed for the 7.62x39 and should stay that way. I would look into a 5.45 upper for a AR-15 rather than anything by CAI. I didn't like their quality and totally lost respect for them with their BS version of the vz58.

 

[Joe Williams]

What are the chances of so many tumbling bullets hitting exactly side ways so many times? Seems fishy to me.

I don't know. Cathy owned a Taurus 970 Tracker that would make holes like that after about 200 rounds if we were using cheapo bulk ammo. Exactly sideways at 25 yards.

I don't know if the bore was rough, or just very tight, but some bulk ammo is rather variable in size. After a couple hundred rounds, barrel would lead up. It wouldn't do it with better quality ammo, like mini-mags.

Thought about sending it to Taurus, but decided not to mess with a good thing. See, until you passed the 200 round or so mark, that thing would put even bulk ammo into a 25 yard group slightly smaller than a quarter, and mini mag grouped barely bigger than a dime. Incredibly accurate gun, with an awesome trigger. We didn't want to take a chance on messing up the good stuff, so at the range I'd just take a few minutes and scrub the barrel out when the first keyholed round appeared.

Cathy sold it to help with moving expenses when we moved here from PA, and wants another badly. She loved that big ole gun. Only downside to it aside from having to either shoot expensive ammo or clean it every couple rounds was that it would wear your arms out shooting it. Thing weighed a ton.