Why Penetration > Expansion

[curioushooter]

This is a little buckling and presented a nearly ideal broadside shot, but it was not exactly perpendicular. He had eluded me a few times already, so I decided to take the shot at about 30 yards.

The .357 Magnum carbine with 180 grain XTP did its job very well penetrating both sides of his body cavity and one of his shoulders. As you can see the wound track was devastating though it grazed his rumen unfortunately. As typical of Hoosier whitetails he had been eating a lot of corn! No bullet fragments were recovered.



Because of the angle over 21" of penetration was needed to accomplish this. Earlier on this subforum folks said my 24" ideal penetration parameter was too much. I say it ain't and here is some proof. Had this been a more meaty critter it would have easily had to go 24." Since I process other deer I've gathered that penetration of about 24" is needed, but until now I've never had photographic evidence or the whole truth as to the presentation, ammunition, etc. In the open condition the chest cavity expands about 1". In his live state you need to penetrate the hide too, which easily adds that inch back, so 20-21" is the true wound track length.

[BK7saum]

But then you have the question of whether you want all the energy dumped in the animal or have wasted energy of a complete pass through. Only 14-17" needed to reach the vitals. Just different needs/wants/arguments. I prefer a pass-through if possible, but I don't necessarily load all my ammo to get that parameter accomplished.

[leadeye]

A good pass through with a large caliber bullet has always worked for me. These days when the bullet destroys the shoulder I make a decision on whether to take the time to pick the meat out of the tangle. I'm down to just feeding the wife and I, two old people don't eat that much.

[bowfin]

But then you have the question of whether you want all the energy dumped in the animal or have wasted energy of a complete pass through.

I don't see this as "wasted energy" as much as I would say "surplus energy". My opinion is that an exit wound is decidedly advantageous in harvesting deer. How much energy is in the bullet when it pokes through the other side is a moot point, since all the damage to be done has been done. Deer seem to bleed more out of an exit wound than an entrance wound and a blood trail that looks like it was put down with a spray can is reassuring, whether it goes for ten feet or 50 yards. My views come from harvesting 75-85 deer personally and another 300 from the immediate family. Your views and experience may lead to a different opinion, though.

[BK7saum]

No, not disagreeing at all, but merely stating different possible viewpoint. But what caliber and how much energy. 300 rum with 230 Berger will pass through a whitetail and likely have hundreds or more ftlbs of KE left over. Obviously not the situation here with a 357 max, but...how much surplus energy plays into recoil and ability to shoot a firearm well. I totally agree with all of your facts or premises, it is advantageous, just not necessary to kill a whitetail efficiently.

[megasupermagnum]

I never said 24" through an animal was un-needed. What I said, was that 24" into your ballistics gel does not equal 24" in a deer. I seem to remember you reporting only 13" maybe 16" into your ballistics gel block with that bullet. Since it went all the way through 21" of deer here, which mirrors my experience with that bullet, that pretty much tells the story. Ballistics gel is a fantastic test medium for comparative purposes, but it is not even close to a 1-1 with a live animal.

[mnewcomb59]

Ballistics gel is a fantastic test medium for comparative purposes, but it is not even close to a 1-1 with a live animal.

It is not supposed to represent an animal. It is for comparing penetration. He now has a great gel number in his head that he can compare future loads to. Lets say he got 16" in organic 10% porcine@ 40 degrees, or 20% porcine at room temp, or clear gel, or water. He knows if he changes loads what penetration he likes.

If he gets the same or 10% more penetration with a different load he can be reasonably sure that he can take quartering shots on deer and get good results. If he tries a different load and gets 30% less penetration he will know to not shoot it at a deer.

I killed one deer by "dumping" around 1200 foot pounds into the first lung but the second lung only had a pin hole. The boolit (soft 140 ranch dog @ 2000 fps impact velocity) had 100% weight retention and penetrated 12-14" gel or 3 milk jugs. That was the longest tracking job I ever had at over 200 yards with more than a fist sized hole in one lung and no exit wound.

I killed 5 more deer with that boolit and load, but changed the alloy to where I got 5 jugs of penetration and had exit wounds on every deer with 0-50 yard tracking jobs.

Bottleneck rifle JSP deer bullets penetrate 5-7 jugs from 30-30 to 30-06 and 7mm mag. This is equal to 20-30" of gel.

I killed two deer last year with Texas heart shots and loads that penetrate 5 jugs. One was accidental and was already down from a shot through two shoulders that exited. It was hobbling away from me on its front elbows and I was trying to shoot it in the back of the neck. The boolit hit the ham, hip bone, several vertebrae and was found above and in front of the front shoulder in the backstrap. The other was a hard quarter and the freezer was low, so I sent it through the rear ham, next to the butt hole without hitting bone, and likewise this bullet was found in the opposite backstrap in front of the shoulder. The second deer was with a 1911 set up for 45 Super shooting a NOE 255 cup point around 950 fps, the first was the 357 rifle with the NOE 154 WFN weighing 158 in 2-2-96 at 2050 fps MV. I have found that penetration is more important than muzzle energy.

I have also killed deer with loads that penetrate 8-12 jugs and was not satisfied with the size of the wound. Deer were recovered but with a sparse blood trail. When dealing with low power cast boolits I try to find the goldilocks zone where you get controlled expansion and ENOUGH (but not excessive) penetration. I don't like a boolit that penetrates too little and I don't like a boolit that can kill 3 deer in a row because it makes a narrower wound than the same boolit carefully calibrated to have just enough penetration for a hard quarter or Texas heart shot.

I have not killed a deer with a cast boolit that has over 1500 foot pounds muzzle energy, so maybe a 10 jug penetratin' boolit with 3000 foot pounds will kill 'em just fine, but with my 357 rifle I like to use my energy wisely and tweak alloys so the boolit barely mushrooms at 100 yards and moderately mushrooms at the muzzle.

[megasupermagnum]

It is not supposed to represent an animal. It is for comparing penetration. He now has a great gel number in his head that he can compare future loads to. Lets say he got 16" in organic 10% porcine@ 40 degrees, or 20% porcine at room temp, or clear gel, or water. He knows if he changes loads what penetration he likes.

That's what I've been trying to say, but Curioushooter is dead set that he needs 24" of ballistics gel penetration, despite real world results to the contrary.

[bmortell]

i havent seen "energy dump" reliably doing anything to deer on chest hits. for a while i tried to make the most shocking jacketed rifle loads possible and they just tank the hit like a pebble hit them and run full speed till blood loss gets em anyway. so i think getting the biggest exit you can is the best way, and i suppose getting a bigger exit means you need leftover energy to make that exit bigger.

[mnewcomb59]

That's what I've been trying to say, but Curioushooter is dead set that he needs 24" of ballistics gel penetration, despite real world results to the contrary.

That is not a bad number to aim for because your basic JSP deer bullets in bottleneck calibers penetrate 20-30" organic 20% gel.

[megasupermagnum]

That is not a bad number to aim for because your basic JSP deer bullets in bottleneck calibers penetrate 20-30" organic 20% gel.

And yet he just got great results on a deer with roughly half that.

[smoked turkey]

In my experience a pass through shot is given the nod as the most beneficial to the hunter in that it seems to produce the best opportunity for the animal to bleed out and expire quicker. A well placed shot trumps a poor one any day. The deer can find a place to hide in the timber and valleys we have around here. The quicker the animal expires the less distance they travel before giving it up. That is always good I think. A less than ideal shot can have an almost dead deer travel up to 3/4 of a mile before it is done. I believe if you can have penetration and expansion both it is ideal. I avoid direct shoulder shots due to the excessive meat damage inflicted. My shots here are mostly under 35 yards, thus I have experienced the excessive damage to the shoulder I spoke about.

[ChristopherO]

I cast for penetration and some expansion in the 405 FN 45/70 bullets. Easy pass through in the chest and enough energy when hard quartering away shots are necessary. When a rear ham is hit and yet the boolit still ends up in the chest cavity, making holes in the heart/lungs, that is a good projectile, in my humble opinion.

[MT Gianni]

In the late 80's & early 90's I became enamored with Barnes X bullets. I shot 3 antelope, 6 deer an Elk and a Shiras Moose with them. I recovered only one bullet, from a 308 at about 2700 fps. It had penetrated 62" of Moose. Do what works in your area but I am happier with 30" of penetration than I am with 24".

[white eagle]

21"-24" 30" or 3' its the animal on the ground that counts

[444ttd]

penetration, penetration and finally penetration. i'm a big believer in pass thru's and heavy for caliber fn, wfn & lfn boolits. "energy dumps" and biden voters are the same thing, it didn't happen.

notice my signature,
"The religion of KE: proposed by the ignorant, and parroted by the unknowing" - MikeG

[waksupi]

I want pass through, deer or elk.

[Mk42gunner]

I too prefer a complete penetration vice an internally disintegrating projectile. If nothing else, it is likely to leave a better blood trail for those occasions when the quarry doesn't drop within eyesight.

Let's face it: comparing projectiles that will reliably kill a deer (or anything larger) is like comparing apples to oranges to peaches to pecans.

Robert

[curioushooter]

Energy dump is nonsense. Energy doesn't kill animals. If energy made any sense than a bow and arrow should be next to useless, yet they are proven to be highly effective. For example my 45# hunting re-curve and the arrows with broad-head I use comes in at a MEASLY 98 joules of KE at about 10 feet. Compared to a 38 special 148 wadcutter load out snub nose at over 200 joules of KE! If energy were what mattered that 38 snub with wadcutters would be DOUBLE the effectiveness of the bow and about equal to the 200# longbows that could take out armored horses at 200 yards! The truth of the matter is that the Zwickey Delta broadhead cuts a 1" or larger slice all the way through the animal like you ran a sword through it. It bleeds a LOT!

Bullets/arrows kill by creating a wound. Unless that wound is through the CNS, which causes instantaneous stun, the wound basically leaks blood (which is why pass through is great, two holes instead of one), which causes blood pressure drop, which causes anoxia of the CNS. All higher vertebrates die due to "BRAIN DEATH." Larger wounds leak blood more rapidly, so anoxia of the CNS sets in more rapidly.

The size of the wound is a function of bullet shape in medium (so expanded bullets, which take on another shape in medium, needs to be considered) multiplied by length of penetration. It is my opinion that the matter of meplats and such matters only a little. I can say that expanding bullets matter a lot because they can double or triple their frontal area. Multiply this frontal area by the lenght of the track and you get a rough estimate of wound volume. This is my means of comparing bullet performance and I think it more rational and in keeping with observation than anything else.

I do realize that lungs and most of the organs are far softer than muscle. Ballistic gel and "meat targets" are functionally like muscle. In fact, this is how you calibrate ballistic gel: you shoot a piece of meat with a 17 caliber steel bb from a air rifle at about 600 FPS. You then fine a ratio of gel/water that exactly equals the penetration depth of the meat with that BB. Both fresh deer and fresh and aged wet pork get about 3-3.5 inches. It is my understanding that bipedal primates are in this range as well. I adjust the ratio of gel to water so that I get 3-3.5 inches.

I've used both MEAT and calibrated ballistic gel to test bullets and came away realizing that gel is a far superior medium that is completely comparable to muscle, which is tougher than the organs. So if you get 21" or whatever in gel you will get this in muscle and even more in softer tissues. Bones are another story, and it is really hard to get any data on them. Needless to say they are far tougher than any water-based tissue and I reckon a single heavy bone hit squarely presents more resistance to a bullet than perhaps a foot of gel or muscle.

Still this is why penetration is king in my mind and chasing after expanding hollowpoints is worthwhile ONLY IF YOU ARE GETTING AMPLE PENETRATION. All my testing of cast HPs show that they expand TOO well and they tend to under-penetration when compared to well constructed JHPs like the XTP. On a certain level I think a bigger caliber heavier cast bullet is the way to go for this reason. It is certainly simpler to approach it this way. If you want expansion stick with a XTP or other quality JHP (which use their jacket of copper to arrest the expansion of the bullet) or at the very least TEST your cast HPs.

The good news here is that cast bullets of standard weight for caliber (like 158 for .357, 210 for .410, 250 for .429, etc) solid cast bullets at moderate velocities (<1400) are superb perpetrators. Even at leisurely 38+P special velocities I've observed the 358429 go 28" in gel. So classic big bore hunting revolver loads like Keith's are solid loads and truly can hold their own against anything today. They will be heavy on the penetration and sort of light on the wound diameter but will be reliable if a bit unimpressive.

[244ack]

2 holes are always better than one , ill take the extra penetration any day