Tumbling?

[newguy]

What would cause a bullet to impact the target sideways? This has happened twice now. The ammo is russian wolf or tula and the rifle is a sks. Its never happened before so im thinking its the ammo. Just curious what would cause this.

 

[ol' Huff]

At what distance? If its far enough away the bullet has dropped transsonic? Is possible the rifling has worn to tje extent that it can no longer stabilize the bullet. It's possible the rifles had system is loading enough gas somewhere that it is no longer generating enough velocity to stabilize the round.

Basically, though, when you get sailboats on your target it is because something is not 1. spinning the bullet right or 2. pushing it hard enough.

Got a little more info?

 

[Mgderf]

It's called a "Keyhole".

Glossary of firearms terms - Wikipedia, the free encyclopedia

For whatever reason your bullets are not stabilizing. It could be your bullets are too heavy for the twist rate of your barrel.

 

[Dead Duck]

Keyholes happen to my AR "Type" rifle when I throw 62gr through the 1:12 twist barrel. Using 55gr takes care of the problem. (or using a 1:7 twist)

Same science applies to the 7.62.

BTW - Wolf and Tula are not only inexpensive, but "Cheap" as well.

 

[newguy]

Its only happened twice out of about 60-80 rounds so im thinking its cheap tula ammo.

 

[nater30/30]

100% of the instances I've dealt with key-holing it was fouling. Severe lead in my personal case, my early days of reloading I was pushing cast way to hot in a 30/30, not paying close attention to bore condition, I experienced tumbling in early jacketed load development. I was a self taught teenager lol, I've came a long way in the past couple of decades. The other 3 instances were buddy's rifles, interestingly, all Mosins; 2 91/30's and a M44, all combo of cosmoline/pure filth. I found it interesting how little of an amount, and/or how soft a substance can be to swage a hard, jacketed bullet. It occurred to me while shooting .318" bullets with factory 8x57 in a thoroughly clean .324" groove diameter bore with no tumbling, sparking my skepticism to the reports of AK-74's key-holing with just a few thousandths oversized 5.56 barrels on them, and I, having no ill effects with a .006" oversized bore...cause as fouled grooves will swage a bullet down to just the diameter of the lands, a clean one will allow it to swage up and fill the grooves with the resistance of the lands. The length of the bullet's bearing surface is a major factor also, spitzers are more susceptible to swage just to the diameter of the lands cause they have far less bearing surface. The hardness of it's self and/or it's jacket's a factor also.

 

[throttletony]

Its only happened twice out of about 60-80 rounds so im thinking its cheap tula ammo.

This could very well be the case, maybe a couple underpowered rounds.

 

[newguy]

I had one round that was a failure to fire except it did in a way. As i rechambered another round i noticed i had unburnt powder in the chamber. Taking a closer look i noticed the bullet had travel a 1/4 or less down the barrel and stopped.

 

[nater30/30]

I had one round that was a failure to fire except it did in a way. As i rechambered another round i noticed i had unburnt powder in the chamber. Taking a closer look i noticed the bullet had travel a 1/4 or less down the barrel and stopped.

Dang, maybe you got a bad lot. Thank God you checked ur bore

 

[roadrunner681]

I had one round that was a failure to fire except it did in a way. As i rechambered another round i noticed i had unburnt powder in the chamber. Taking a closer look i noticed the bullet had travel a 1/4 or less down the barrel and stopped.

squibs can kill good thing you caught that, 7,62 in my experince will tumble if its underloaded, i dont think the bullet is going fast enough for the rifle to stabilize it like having to slow a twist rate in the extreme.

 

[ilcaveman]

Your a lucky man

 

[Tombs]

How clean was your bore when you first noticed the key holing? Was the rifling still crisp? Was the muzzle crown still in servicable condition?

 

[ryknoll3]

I've heard of problems with TulAmmo. Does it happen with the Wolf as well?