[Quilbilly]

I was shooting a few weeks back out in the woods and noticed a chunk of mostly rotten wood with bullet holes in it. After breaking it apart a little, I found a couple hollow points all mushroomed out. Last week I was messing around and tried to do the same with some older gold dots I had laying around and could not make them mushroom hardly at all. I found about 6 of them and only a couple changed shape at all. So that got me wondering. How do you shoot and retrieve mushroomed rounds? Also, why is there a difference in the effect on the bullet in wood rather than a person?

[Funderb]

modern hollow points are designed to expand specifically in substances of the hardness and density of flesh. I suggest a large chunk of pork.

[kd7nqb]

A buddy of mine called a local game processor/ butcher and found that occasionally meat gets something on it or falls in a way where it cant be sold for food. He was able to get it discarded to him instead.

NOTE- I have NO clue if this is legal or not so I am not sharing the name of the butcher, I think they had an understanding that the meat was only for "Testing" and if the guy grilled it up instead it was his own damm fault.

[ArmedBear]

Hmmmm....

Anyone up for meeting somewhere in the great Northwest for a Meat Trap Shoot?!?:D

In dog training, we use big slingshots that huck dead ducks high into the air. These could serve additional purposes, I think.

http://www.lcsupply.com/Product/Training-Aids/Zinger-Winger-II.html

[Quilbilly]

Very interesting. Wish I could wrap my mind around the physics of it.

[ArmedBear]

I'm not entirely sure that there can exactly be a physics behind that, but that said...

My guess is that it has to do with fluid dynamics more than hardness and density - the waves produced when bullet hits fluid initiate expansion in ways that smacking into solids like wood wouldn't. Just a guess (and also a reason to distrust those magic hollowpoints -- humans, bears and other possible attackers are not a single density, nor a fluid, like gelatin).

Yeah, I have my HD gun loaded with high-tech hollowpoints. But it's also a .45. Why not hedge my bets?

[CountGlockula]

Found a Youtube vid of a shotgun slug into a piece of meat:

http://www.youtube.com/watch?v=aAXOfIdBgcM

He didn't extract the slug, but the meat looks tenderized.

[UKJ]

Now all you have to do is find the owner of an indoor range who'll let you shoot up Miss Piggy.:)

From the various gun tests I've seen on the Interwebs, gelatin blocks seem to be a favourite as a human analogue for penetration / expansion of bullets (I watch too much Mythbusters).

Though I've noticed expansion shooting into gallon milk jugs filled with water, if that's cheaper and easier.

[rcmodel]

My guess is that it has to do with fluid dynamics more than hardness and densityYou win the cigar!

A HP depends on liquid getting inside the cavity to initiate hydraulic expansion.

Hardness & density also play a part in it.
A hard lead alloy takes more velocity to expand then pure soft lead.

Magnum JHP bullets use a thicker jacket and harder core to retard expansion at the higher Magnum velocity.
A thin jacket & soft lead core might expand too much, too soon, and not have sufficient penetration.

If the HP cavity clogs with dry wood fiber, goose down, clothing fiber, etc. before the fluid gets in it, expansion will not take place.

If you want to recover bullets and study expansion you can use water jugs, wet sand, mud, wet phone books, ballistics gel, etc..

As long as there is enough moisture in it, and they are going fast enough, they will expand.

rc

[Quilbilly]

This would explain why the moist, rotten wood worked better. Thanks guys.

[rcmodel]

To further expand on the hydraulic pressure expanding a HP bullet.

A solid (dry wood) cannot be compressed much at all.
It becomes a solid stack and only exerts pressure on the bottom of the stack.

A fluid cannot be compressed either, but it exerts pressure equally in all directions when you try.

The "in all directions" is the key to why the fluid filled HP cavity expands sideways and opens up the bullet.

http://www.tpub.com/content/engine/14037/img/14037_67_1.jpg

rc

[ArmedBear]

This is why I don't put all my trust in hollowpoint bullets

IF I ever have to use them, and they expand, hey, great.

If they don't expand, I don't want to be using a caliber that relies on that expansion in order to achieve a rudimentary level of effectiveness.

The common assertion that modern bullets make the 9mm adequate for any defensive purpose, and make larger calibers unnecessary, should at least be tempered with "if everything works in your real-world defensive scenario exactly as it does in the laboratory..."

[Ben Shepherd]

Very damp to wet(NOT mud) in a box works pretty well for testing......

And it's cheap.:D

[jaydubya]

Or, you might check www.brassfetcher.com for ballistic jelatin results.

Cordially, Jack

[CWL]

Make your own ballistic gelatin for testing. Go here and click the "professional ballistic gelatin" link for pricing and kits.

http://www.vyse.com/about_us_brochures.html

[Ohm]

Has anyone heard of putting wax or silicone caulk into hollowpoints to provide that squishy center to initiate expansion?

[Claymore1500]

Has anyone heard of putting wax or silicone caulk into hollowpoints to provide that squishy center to initiate expansion?

Rumor, Doesn't work.

[eitrheim31]

bullet velocity at impact is a big factor as well, probably not a factor in your case but probably worth mentioning

[-v-]

At the same time, looking at Federal EFMJ, Powe'r'ball, and the new Hornady FTX bullets, I do have to wonder, as all three of those have one thing in common: Some sort of silicone plug in the hollow point cavity that ensure expansion 100% of the time. One has to wonder....

[eitrheim31]

i was thinking that was to prevent material like clothes from filling the cavity which prevents the fluid dynamics necessary for expansion. they're designed differently from other hollow points

[Dirtpile]

Indeed they are. The EFMJ expands by being flattened. The nose area over the slicone ball is pre-notched and the ball is very soft so it compesses and helps push the "petals" out.

The FTX is designed like a ballistic tip rifle bullet with a narrow secondary cavity under the tip that it gets pushed into to initiate expansion. The lead is softer for the lower velocity.
The Pow'R'Ball is similar in that the ball does not completely fill the cavity but they seem to be a little too soft for the velocites they're loaded to. (I've seen several tests where the majority of rounds fired just blew up rather than expanding.)

[CWL]

At the same time, looking at Federal EFMJ, Powe'r'ball, and the new Hornady FTX bullets, I do have to wonder, as all three of those have one thing in common: Some sort of silicone plug in the hollow point cavity that ensure expansion 100% of the time. One has to wonder....

But it doesn't ensure expansion. Testing of EFMJ & Pow'rball ammo has shown that they do not expand as reliably as good JHPs. These are better for areas that do not allow JHPs like New Jersey.

[Kind of Blued]

Really? Nobody has suggested shooting water? Maybe I missed it.

From what I can tell, the OP just wants to retrieve a few hollowpoints for giggles, so accurately simulating human flesh isn't an issue.

Save your milk jugs, juice containers, motor oil containers, laundry detergent containers, etc, and wash them out. Fill 'em up with water, put a couple phonebooks behind them, and shoot. You only need a few inches of water to get the bullet to expand, and the phonebooks should catch just about any pistol round.

From what I can tell, water likely exaggerates expansion, but they still look cool.

[marcodo]

I have shot down into a gabage can full of water (standing on the second floor of my outside deck)

Have shot hollow points of 9mm 9 mm+P 45 45+p 38 357 and 380.

All were recovered with no damage to the gabage can.

It doesn't tell you about penetration but sure does give you pretty bullets to look at

The Federal HST expansion was amazing

[ArmedBear]

ensure expansion 100% of the time

LOL

Nothing ensures anything 100% of the time in the real world.

Still, if clogged hollowpoints are a problem, these new designs do make a lot of sense.

[heron]

I'm not entirely sure that there can exactly be a physics behind that, but that said...If it's physical, it has physics behind it somewhere . . .

[ArmedBear]

LOL

I meant that, much like Nutrition, legitimate Physics is a very different field from Marketing.:D

[rcmodel]

Has anyone heard of putting wax or silicone caulk into hollowpoints to provide that squishy center to initiate expansion?

Rumor, Doesn't work.Truth. Does too work!

Melted candle wax in a cast lead HP will insure expansion.
We were doing it 40 years ago before JHP handgun bullets were invented yet.

Don't know why silicone seal wouldn't work as well.

Even Hornady thinks so.
Check out the adds for the new Critical Defense ammo.
http://www.hornady.com/story.php?s=786

rc

[Mr.510]

I "test" hollow points into a 5 gallon bucket of wet phone books. I tear the spines off the phone books so I can stack the pages flat to about 2/3 the depth of the bucket. Then fill the bucket with water and let it sit overnight. The phone books expand almost to the top of the bucket as they suck up the water. I put the bucket at the base of a five foot diameter boulder in the gravel pit where I shoot and fill it to the top with water. Then I stand on the boulder and shoot straight down into the bucket. I've only had one round exit the bucket, it went out the side about 8 inches down from the top. That's why I stand on the big rock! :what: Federal HSTs out of my XD45C penetrate 14 inches and expand just like the pictures in their ads. They are damned impressive to look at. We tried some Gold Dots out of my buddy's 3" 1911 and they did not expand. :banghead: To my surprise they didn't make it out the bottom of the bucket either. We didn't measure penetration but they were all within a couple inches of the bottom. The next time he goes shooting with me we'll try HSTs from his 3" barrel and see what happens. :D

[RyanM]

Truth. Does too work!

Melted candle wax in a cast lead HP will insure expansion.
We were doing it 40 years ago before JHP handgun bullets were invented yet.

Don't know why silicone seal wouldn't work as well.

You beat me to it. Around here, we use hot glue. Works fine.

[Odd Job]

Water tank is cheapest. Ideally fired from vertically above.
I have noticed that some JHPs when fired in a proper ballistic tank end up with an angled expansion and aren't quite as photogenic.

[76shuvlinoff]

This explains why when I launched a .45 Hydrashok into a treated 4x4 it came out the other side unopened. I thought it was due to a short barrel and lower velocity.

Actually just the tip of it was sticking out the other side, made retrieval easy though.

[WardenWolf]

I don't truly trust expansion. I much prefer having a round that's going to ruin the person's day even if it doesn't expand. Anything that creates at least a .40 caliber hole is going to do that. I still prefer .45, though.

[andre73]

I just did a bunch of expansion tests using water:

videos (http://www.youtube.com/andreleger2001)

HST's were great!

Im still editing some that I have not yet uploaded.:)

[Hungry Seagull]

Mr510, We actually prefer that the Gold Dots STAY inside the badguy. Just a little ... internal reminder and encouragement when he reaches teh other side standing in front of the pearly gates with the bullets falling around his feet.

The Federals look durn good. But what can I say? Go for it.