Cast boolit expansion in .45acp... What have you found?

[fastfire]

Still only rotates once in 12" penetration. The forward energy is far greater than the rotational energy so in solid matter my bet is the rotation stops before the penetration does.

FWIW http://www.youtube.com/watch?v=d2taJFU1vG8

[fastfire]

Still only rotates once in 12" penetration. The forward energy is far greater than the rotational energy so in solid matter my bet is the rotation stops before the penetration does.

FWIW http://www.youtube.com/watch?v=d2taJFU1vG8

[snuffy]

Great eye candy Mtgun44, can't get enough of that picture!!!

Interesting about how "slow" the 45acp's bullet rotation is. It's only 37,000rpm or 600+rps from a standard 230gr 830fps ball ammo. When that bullet hits something it's spinning @ 600+ revolutions per second. Anyone who says a 45acp will only spin once or about once in something as thick/wide as a deer doen't have a clue about the 45acp cartridge. Anyone care to count past 1? A 200gr 45acp bullet

https://www.google.com/url?sa=t&rct=...1x49Zk569QcS1Q

A 230gr 45apc bullet

https://www.google.com/url?sa=t&rct=...IEKEydikGQyGVA

As far as a standard hp over a penta point hp, that's been proven decades ago. That's why all the mfg's are making hp's that open up with spears/talons/pedals or whatever else you want to call them. The penta's will open up as big as their standard round hp cousins but because the penta's are not a solid mass (solid frontal area) they will have less resistance. Same weight, same speed, less resistance ='s deeper penetration.

The "blender effect" is a side bonus of these types of hp's, they send lateral shock wave out as they spin (more than 1 revolution). This is an excellent video that shows the lateral waves in the ballistic gel, you can actually count the # of revolutions the bullet did in the gel & visually see the waves.

http://www.youtube.com/watch?v=9HRtf...AF8B48&index=1

Penta style hp with it's pedals, arms, spears, talons or whatever you want to call them have been out for decades, used by every major sd ammo mfg in every handgun caliber for a reason.

FWIW http://www.youtube.com/watch?v=d2taJFU1vG8

Uh-huh, you didn't read the entire thread,,--did you?

I don't think we convinced those that believe in the propeller/blender effect of bullet spin in media.

[loaded303]

Bad to the bone

[Forrest r]

Uh-huh, you didn't read the entire thread,,--did you?

I don't think we convinced those that believe in the propeller/blender effect of bullet spin in media.

Save your breath, it's hard for most people to understand what's truely involved with the mechanics of a hp & how they function. Here's a classic example, mt44gun is supposed to have 2 degree & this is what he knows after looking at this.

Attachment 101890

The "high acceleration zone" in the image is much LOWER centripedal acceleration than
the parts farther from the axis of rotation. The force is Rsquared times omega, where
omega is the rotational rate in radians per second.

I call baloney, and won't be spending any more time on this silly thread.

Bill


2 degrees and he managed to figure out that the "high acceleration zone" has a MUCH LOWER centripedal acceleration than the furthest end (open end) of the hp, BRILLIANT!!!! What amazes me is that his 2 degrees can't see that it doesn't matter how much greater the force is on the furthest point from the axis is (outer open edge of the hp that is furthest from the center of the bullet). The force in the high acceleration zone will always be higher/greater. The high acceleration zone supports the furthest point from the center/axis of the bullet.

Last I knew 10 year old 5th graders were taught about levers & this is nothing more than applied force to a high stress area. Don't think so then try this:
Take a 20# sack of seed, hold your arms out & have someone set that 20# bag on your outstretched arms right next to your shoulders (high acceleration zone) and hold it there for 1 minute. Take a break & then pick up a 5' long 2# board and again hold your arms out and extend the 2# board out with your hands and this time put a 18# bag of seed on the end of the 5' board that is outstretched by your arms/hands (the outer edge of the bullet furthest from the axis/center of the bullet) & try to hold it there for 1 minute.

It's that simple, doesn't matter if more force applied to the outer edge of the bullets the high stress zone has to hold/withstand that force or the hp will fail. And just like with any other lever out there, the further away/longer the lever, the greater the force is multiplied. If a guy with 2 degrees can't figure this one out I really don't expect other people to.

forrest r

[loaded303]

I just load to my gun spec, shoot, and try not to over think too much on the rest.