Adventures in forensics

[Ian]

Trying to prevent mushrooming is the challenge here, at least for my purposes.

 

[pokute]

I just read some dope by Julian Hatcher from 1919 where he described deformation of exposed lead noses as occurring not from impact with the sawdust, but while the bullet was traveling down the tube. He thought it was an absolute limiting factor in accuracy in the 30 caliber rifle. I wonder if there has ever been any high-speed photography that supported his contention.

 

[Intheshop]

Pokute,in archery it's called the "critical zone" .... and it IS where most drop the ball,so to speak.

 

[Intheshop]

Interestingly, considering my recent phone issues .... doh. My boys,who are light years ahead if me educationally,have some pretty durn accurate slow-mo on their phone vids.

We were at a tune up shoot a month ago;even I was impressed with our technical prowess during the critical period of shooting,looking at the vids right after the shot.So,how well you manage the shot is part of the equation.

 

[pokute]

The points of arrows get blunted when they are loosed? That's a new one on me.

 

[pokute]

And why does Ian want to prevent mushrooming? I've gone mushrooming. It's a great way to get fresh mushrooms. This thread has become totally unintelligible.

 

[fiver]

he wants to stop the bullet as pristine from the barrel as possible.
the only way you can see what 40-50K of pressure is doing to the places on the bullet we know are being affected.
slamming them to a stop or mushrooming up the nose is not going to make that any easier.

 

[Intheshop]

Uhhh,OK... Poduke,whatever,haha.

 

[pokute]

he wants to stop the bullet as pristine from the barrel as possible.
the only way you can see what 40-50K of pressure is doing to the places on the bullet we know are being affected.
slamming them to a stop or mushrooming up the nose is not going to make that any easier.

Yes, I understand. What I was trying to say was that Hatcher reported (1919) seeing a certain small amount of mushrooming on bullets with exposed lead noses that he attributed to some kind of inertial effect in the bore. I am skeptical, but since it was Hatcher reporting it, I assume there was a reason. Unfortunately he did not elaborate.

 

[Ian]

I'm sure you can generate some connections to some really high frame-rate motion picture gear, why don't you endeavor to answer that question? Might even be better than recovering bullets because mid-air photos would remove all doubt about impact deformation.

 

[pokute]

Hmm... Some guy named Ian talked about nose slump in this here forum. Any new observations since 2016? You seemed skeptical of the possibility of inertial deformation too.

 

[freebullet]

Nice work, Ian.

 

[Ian]

Thanks. Just a start, though, this trap thing is going to get a lot of use, and my new phone might actually be able to take better photos than my camera. Been way busy with the kid and expanding the water catchment system, and a couple other projects, and getting ready for a vacation trip, but I'm pretty pumped about getting some more HV testing in this year. It's really nice to be able to see the results of what's happening in the gun so easily.