a poll to settle an argument on terminal ballistics

[caribouhunter]

hi everyone!
i'm having an argument with someone about terminal ballistics.
so i tought about starting a poll on nosler forum to see what guys in here think of it.
please take 30 sec to answer which of the 2 following statement is true.
if the majority think's like him, i'll let him win :roll:

1- a bullet may hit a target (read deer) so fast if shot from short range at high velocity (3300-3500 fps) that it will not have time to start expending and will just pencil thru. it's a law of physics

2- any bullets, in any targets, will expend more as velocity increase. the faster the bullet, the bigger the expansion, up until it's fragmentation.
and it cannot be otherwise, it's logical.

thank's for your time.

 

[nvbroncrider]

That's not as straight forward as it sounds. Depends on your bullet. That right there is the key factor just look at the BT varmit versus hunting. There's part of your answer.

 

[caribouhunter]

That's not as straight forward as it sounds. Depends on your bullet. That right there is the key factor just look at the BT varmit versus hunting. There's part of your answer.

so your answer would be 1 ?
depending on bullet construction, you say it may happen?

 

[JD338]

I have never been able to understand how an expanding bullet won't expand but pencil through a game animal if driven too fast.

Bullet construction is everything and you need to use the right bullet design and weight for the application.

JD338

 

[Guest]

I'm with nvbroncrider. It's not that simple. Assuming equivalent construction, I'm going with answer #2. But, I can shoot a Nosler E-Tip at 1500fps and it won't open reliably in a deer. I can shoot the same round at 3400fps and it will open within 6", which is well less than the deer's "thickness." I could shoot a very tough, stoutly constrcuted bullet at hyper velocities and it might not open. But, that same bullet won't open at lower velocities, either, in this case. I guess, unless you're comparing a varmint bullet to a heavily constructed big game bullet, the #2 answer is correct. If you're comparing the different bullet styles, you're going apples-to-oranges, and it's totally invalid.

Oh, and in reality, #1 is never going to be true, I don't think. Even at 4000-4500fps impact velocity (which is just about the limit of modern smokeless powder firearms), you're going to get some sort of expansion within the 8-12" of penetration through a deer, regardless of the bullet, unless the bullet design is poor and it fails to open. And if that's the case, slowing it down isn't going to change that at all, I suspect, and it's going to fail to open at lower velocities, too.

Think of it this way - as soon as that bullet hits that deer, the nose is slowing down, and at a much faster rate than the heel of the bullet. That's why expansion occurs the way it does. Only a solid will penetrate with little or no expansion at high velocities. Every expanding bullet I know of will expand more violently and quickly at higher velocities. Again, this is assuming an apples-to-apples comparison of the same bullet at multiple velocities.

 

[gerry]

I have never been able to understand how an expanding bullet won't expand but pencil through a game animal if driven too fast.

Bullet construction is everything and you need to use the right bullet design and weight for the application.

JD338

X2

 

[Kodiak]

A hunting buddy used the 110 gr. Hornady HP in his .270 Wby for years on antelope and some deer. He loved that bullet. It never failed to open! At the usual hunting-distance he chose, around 200-400 yds. the MV of 3500 had fell-off. But I've seen 2-6" sized exit-holes in the antelope and where the bullet DID NOT exit on deer, the insides were as a bowl of jello. I was never tempted to use that bullet on any game animal.

My only experience with HPs at reasonably high velocitys.

Jim

 

[caribouhunter]

sorry if it was not clear. but bullet construction is not a factor here
it's apple to apple
same bullet and same target density.

take the most fragile bullet or the most resistant it doesn't matter.
can you push them fast enough they dont have time to expend thru a target that made them expand well at lower velocity

 

[DrMike]

It would be theoretically possible (though impractical) to drive a bullet at a velocity sufficiently high that it would not expand. The damage imparted to flesh due to the shock and displacement of water would be horrendous, I should imagine. In such a scenario, again stressing the fact that it is essentially impossible to drive a projectile that fast, a projectile would "pencil" through the game. Premium bullets are constructed to permit expansion within a defined velocity range, however.

 

[elkeater2]

I think it got answered, so I'll risk another ballistics question. There is high pressure pushing the bullet down the barrel. There is friction from the rifling holding it back. When the bullet begins emerging, with less surface bearing and less friction until it is free of the rifling, does the bullet take a velocity jump? Does it jump even more the instant it has zero friction? If so, how much?
Like if a .308 bullet is chrono measured at 2700 fps 10 ft. from the muzzle, how fast was it going when the bullet nose was even with the crown? I lay awake pondering such things :grin: I think this is why crowns are so important.
EE2

 

[DrMike]

EE2,

Velocity drops the moment the bullet leaves the barrel. Pressure dissipates and gravity begins a downward drag on the bullet. The crown is important because it gives a measure of insurance on consistent exit pressure for the bullet.

 

[JD338]

sorry if it was not clear. but bullet construction is not a factor here
it's apple to apple
same bullet and same target density.

take the most fragile bullet or the most resistant it doesn't matter.
can you push them fast enough they dont have time to expend thru a target that made them expand well at lower velocity

caribouhunter,

I respectfully disagree with you, bullet construction does matter. Some bullets expand fast, some not at all.
If you can be a little more specific with bullet type and the intended game, we might be able to give you a more complete answer.

I have read a few posts in the past that commented that the AB bullet didn't expand due to a small exit wound. The fact is that it did expand and the jacket folded back against the shank of the bullet making for a small expanded frontal area. The internal trauma was there as they described.

I do not believe that an expanding game bullet designed to expand on a game animal and used correctly to the game for which it was designed for will not expand and act like a FMJ if driven too fast.

JD338

 

[rick smith]

There was an article a number of years back showing the remains of various bullets shot at various velocities. All were shot into the same medium. Think it was in Rifle or Handloader. I got a copy of the chart in my loading room that I use to try to educate people on why not to use certain bullets for hunting.Rick.

 

[caribouhunter]

sorry if it was not clear. but bullet construction is not a factor here
it's apple to apple
same bullet and same target density.

take the most fragile bullet or the most resistant it doesn't matter.
can you push them fast enough they dont have time to expend thru a target that made them expand well at lower velocity

caribouhunter,

I respectfully disagree with you, bullet construction does matter. Some bullets expand fast, some not at all.
If you can be a little more specific with bullet type and the intended game, we might be able to give you a more complete answer.

I have read a few posts in the past that commented that the AB bullet didn't expand due to a small exit wound. The fact is that it did expand and the jacket folded back against the shank of the bullet making for a small expanded frontal area. The internal trauma was there as they described.

I do not believe that an expanding game bullet designed to expand on a game animal and used correctly to the game for which it was designed for will not expand and act like a FMJ if driven too fast.

JD338

thank's JD338 with this sentance you answered-2 :mrgreen:

when i say bullet construction is not a factor , i mean for the poll only.
i know that a tough bullet like a A-Frame is more likely not to expand than a ballistic tip.
but if this same A-Frame opens at 2800 fps, there's no reason it wont open at 3100.

it was what started the argument. a 7mmrum owner was complaining about the 175 gr Aframe he used on a deer, saying internal damage was not great.
my man told him that it was because he shot it from too close, and the bullet didn't have time to expand, and that those RUM were meant to shoot at least 400 yard. implicating that if he had shot the same shot at over 400 yard bullet performance would have been better.
but a least 3-4 others agree with him :roll:
another said that the 30-30 at 75 y is a lot more efficient because from that distance at 7mm RUM velocity, bullets just zip thru WItHOUT EXPANDING.

and so on...

 

[Antelope_Sniper]

CH, the answer is number 2.

I shoot a 7mm STW.
I launch a 160gr AB at 3475 fps.
I've shot critters everywhere from 25 yards to 100 yards with it.

Here's the 25 yard shot. This bullet did not "pencil through:

The lest meat damage, and hence the least expansion, I've had was on the 1000 yard shot. Impact velocity was around 1800 fps. The exit hole was modest, but still larger then the entrance. If the impact veloctiy dropped below Noslers recommended minimum of 1600 fps you might get something resembling a Pencil through.

If someone tells you their high velocity bullet penciled through it really means they missed, and just don't want to admit it.

 

[RiverRider]

I agree with AS, I think no.2 is more correct than no.1.

 

[Elkman]

I belive that of the two questions #2 is the most correct. Here's why as an bullet passes through "any" substance it will meet resistence and will begain to expand or breakup. The amount may be hard to measure but the resistence of the substance will create a reaction on the bullets surface. I don't believe that the laws of physic's will allow it to pencil though, without some resistence. My .02

 

[woods]

Actually bullets penetrate more at a lower velocity

i. Observations from the Sciuchetti Data - The Effect of Impact Velocity
Perhaps the most striking observation from this penetration data is that increasing velocity has a detrimental effect on penetration for nearly all bullets over the entire velocity range of interest. This result surprised me because, while I knew from anecdotal evidence that very high velocities caused even heavy jacketed bullets to fragment or overexpand, I expected that this fall off in penetration performance would only occur at velocities above 2800 fps or so and, that for any given design, there would be a peak in the penetration performance curve, with diminishing penetration following diminishing velocity. In fact, what is observed is that penetration reaches a limiting upper value rather quickly at the lowest velocity the bullet will deform (the hydrodynamic penetration velocity or the plastic velocity) and that penetration tends to deteriorate steadily at all higher velocities. Hard bullet designs exhibit an abrupt step function behavior at this velocity.

The very best performers, in terms of penetration, are those non-bonded premium bullets (e.g., the Barnes X-Bullet and Nosler Partition) which exhibit (on average) essentially constant penetration (~19 inches) over the entire velocity range of interest. The bonded bullets, again on average, are somewhat better (~10%) at penetration than conventional bullets; managing 15+ inches in depth up to an impact velocity of ~2900 fps, against only 2100 to 2300 fps for the conventional and commercial classes of bullet. Yet the non-bonded premium bullets penetrate significantly deeper than the bonded bullets - about 25% more.

http://www.rathcoombe.net/sci-tech/ball ... thods.html

http://www.rathcoombe.net/sci-tech/ball ... nding.html

Just some food for thought :wink:

 

[Oldtrader3]

I am going to go with #2 because it is more true under all conditions than #1 is.

 

[Greg Nolan]

#2 with most any bullet. One exception would be the Barnes bullet. They have been known to completly shed their front petals on impact at very high velocity at close range and leave the remaining solid slug to pencil through. Barnes has been working very hard to overcome that rare occurance with new designs like the Tipped tripple shock.
Greg