Tell me why undersized cast bullets tumble.

[freebullet]

 

[freebullet]

The stills were pull from video @ 70,000fps+.

 

[Ian]

Wow, thanks for posting that.

With 250k fps and a lot brighter light I bet we could see the bullet better, and with a grid background might even be able to see how much it's yawing. The great one million fps projectile video that's all over the net had one good shot of a bullet emerging from a muzzle and I'd love to have seen the exact same shot with a lubed lead bullet, you could have seen everything clearly the way they had it set up.

 

[Ian]

Here's the one:

The link auto-embedded, if we don't want that for some reason, mods please remove the formatting or tell me to.

 

[Brad]

Wow. Seeing a cast bullet slowed down like that would be informative. Even better a variety of sizes, alloys, and lubes to see what happens at the muzzle. Comparison of bullets of different alloys would be interesting.

 

[Ian]

You're tellin' me. My kingdom for that to have been an H&G #68 plain base lubed with SL-68B, and a chance to catch the next six inches of flight.

 

[RBHarter]

These sets proof several exterior theories I have been advised are wrong until there is a hard way to consistently measure the events .

In one frame you can clearly see upwards of 10° vertical yaw ,um, tip, since yaw is technically a left / right action.......or something .

 

[freebullet]

 

[freebullet]

 

[fiver]

with Ian's you can see where it come down the barrel slightly tipped to begin with.

I slowed it down to 1/4 speed and clicked it forward one frame at a time.

 

[freebullet]

 

[freebullet]

 

[popper]

Looks like it actually is cast (maybe?) and has lots of junk on the nose at the lands. Also you can see the escaping gas around the boolit before it is completely out of the barrel. There is some recoil evident in the vid. so I don't think you can evaluate 'tipping'. I was getting sideways @ 7 ft. from the 40. SIL got the same in 9mm at ~15 ft. The 9 had harder alloy and left a nice 'per Accurate print' on the hanging paper target. Very sharp outline, straight base line. Round holes for several shots and then a sideways one. Pretty much has to be small sized and gas cutting/leading. Leading actually strips lube and lead from the boolit, increasing cutting. Actually could be alloy getting messed up between the case mouth and lands. Lots of expanding/squishing going on there. Thks Free, those are ones I wanted to post.

 

[Ian]

I noticed the bullet seemed to jump ahead after it cleared the barrel by about half a caliber. Also agree with Fiver, it was crooked in the bore.

 

[RBHarter]

The air is compressed in front of the bullet inside the bbl because it it doesn't accelerate at the same rate as the propellant driven bullet . There may be some gas escape but I'm reasonably sure that the debris were in the bbl before the shot .

 

[popper]

1 & 2 pics in #28 show gas expelled before it's base is out, also the mangled top groove/bore. Yes, probably stuff embedded from previous shots. Anyway, PCd some 40 FB - base uncoated to see if the BLL just got blown off in the last test. Alloy is just Pb/Zn/Cu. Just trying to find the root cause.