Author Topic: Bullet form / terminal ballistics (Read 1282 times)

slave · « **on:** February 05, 2006, 04:50:02 PM »

If point of impact was a given what is the 2nd most important factor in the terminal performance of a bullet and why?

gwindrider1 · « **Reply #1 on:** February 18, 2006, 05:46:49 AM »

slave,

That's one hell of a complicated question, which would require an even more complicated answer. You might have more success getting this answered if you posted this on the reloading forum. Maybe someone with a very technical background of experience such as Steve Riccciardeli would chime in on this one.

Experience is the greatest teacher! :wink:

JJHACK · « **Reply #2 on:** February 18, 2006, 12:28:03 PM »

This is not at all complicated to answer for me. Actually simple! The absolute most important thing is straight line penetration. Any projectile that will drive straight through after the tip of the bullet impacts the hide has accomplished the second most important stage of killing the game.

Next is staying intact, the more weight retained the greater the depth of penetration will be. The bigger mass will always retain the greatest momentum.

Next is the increase in diameter as in a "mushroomed" or expanded bullet. The greater diameter adds trauma by a significant amount during the depth of penetration. Bullets that do not mushroom or expand tend to zip clean through and deliver much less internal tissue trauma.

All three of these are very important, and although I have listed them in this order they are not far apart in the level of importance. I'm not sure why it was suggested that a fella experienced with reloading would be an exceptional person to advise on this. It's an internal ballistics question on living tissue. For that I have a significant level of experience. over 20 years as a Professional Hunter with well in excess of a thousand big game shot by my clients.

Since I'm the one looking for the animals that have escaped or been lost I know what my priorities are in bullet construction from a "hands on" perspective.

slave · « **Reply #3 on:** February 19, 2006, 06:22:01 AM »

JJHACK & GWINDRIDER

Thanks for the input.

From my bow hunting experience I under stand what jjhack means by STRAIGHT LINE penetration.

So now I need to ask another question.

What factors aid a bullet in straight line penertration and as important what factors cause a bullet to turn after impact ?

JJHACK · « **Reply #4 on:** February 19, 2006, 09:45:51 AM »

Bullets with boatails have the reputation for curving paths internally. I think that has to do with so many people who used military boatails FMJ bullets. I also think that bullets that shed the jacket or sepoerate from the core tend to have each piece go their own seperate ways. A bullet that stays intact usually penetrates straight through.

Even with that said I have seen a significant amount of Monolithic bullets bend upon impact without any expansion. These always seem to curve off track. The Winchester failsafe and Barnes X Bullets from my expereicne will either be the greatest perfomance you will ever see, or a bizzare failure with wierd curving unpredictable penetration. More then one time I have seen the BArnes X recovereed under the skin on the same side the animal was hit. That bullet was in the shape of a banana and curved right back towards the entry side. I have seen this quite a few times. It's nearly always been from guns over 3000fps MV and at or under 308 diameter. I shoot the Barnes X in my 458 Lott and have never seen one bend yet. I think they are too thick at that diameter to bend, and much slower speeds.

From my personal experience the bonded core bullets have given the most consistant performance of any bullet made today.

Don Fischer · « **Reply #5 on:** February 19, 2006, 12:19:01 PM »

Those Barnes X and Winchester Fail Safes that bent, Did they open up at all or did that little hollow point just close up? I've seen that happen in newspaper with a couple different hollow point bullets, so I never use any kind of hollow point for hunting.

I also suspect that when that happens, the animal runs off farther? Hard to relate American game with a lot of African game. Some guys here are relating deer running off 50 to 100 yds and more and they use Barnes X bullets and another a ULD type with what looks like no exposed tip.

JJHACK · « **Reply #6 on:** February 19, 2006, 01:05:28 PM »

Usually when I make a statement of opinion I like to have had quite a bit of resolution to form that opinion. With the Monolithic expanding bullet designs like the X bullet I have not seen enough failures to have a certain understanding of just why they are.

For some time I assumed that they were impacting bone near the surface of the skin and the tips were being crushed into the hollow area. However I have also seen at least a couple that have had perfectly formed hollow points and did not open. So I'm not so sure now. I do know that those I have seen do this were all heavy for bore, or long skinny bullets with MV's over 3000 fps. 100% of them with trouble had that in common. As I wrote above I think they are just flawless in my 458 Lott at 2300fps for the 450 grain bullet.

kciH · « **Reply #7 on:** February 19, 2006, 08:18:52 PM »

Have you had enough hunters using the newer TSX to see if this problem still exists, however uncommon it might be, with the new bullet? The MRX seems interesting, but I think I'd shoot a lot of other bullets first.

I know it has been revealed that there where some problems with the original plastic tipped Swift bullet, have you seen it fail?

Thanks,

Steven

JJHACK · « **Reply #8 on:** February 20, 2006, 04:34:30 AM »

Are you sure the swift Scirraco was the one with trouble? The Nosler Accubond had lots of people angry with the thin jackets seperating and poor retention of eight. I have seen a number of the Swifts used with nothing but perfect performance. If the Hornady interbond was not so much less money I would be using the Swifts now.

The Hornady interbond is the best bullet at the best price I have ever used or seen used to date when shot from rilfes under 3000 fps. When velocities are greater then that I still prefer the swift Aframe in rifles 30 caliber and under. They are built far stronger and do not mushroom back as far. I have shot the 165 grain Interbond and had it turn completely inside out but still remian in one piece. The jacket peeled back over the base until it was all the way reversed with the jacket on the inside and the lead on the outside. I'm sure I have posted photos of that bullet on this site in the past.

My rifle will be used for a loaner this year by 6 hunters In May and June. If I can get the TSX to shoot well enough before I leave I will have some of them use the TSX in my rifle. After 50 plus animals are shot with it I'll have a much better opinion.

slave · « **Reply #9 on:** February 20, 2006, 04:26:36 PM »

I have read that long light FMJ (BALL) or monolithic type bullets often flip end over end after impact. Odd as it may sound it did not seem to reduce total depth of penetration but this may explain some curving internial paths. This occurs more often at higher velocity. Photos of balistics gel show huge amounts of damage form this. But any miss of a vital organ would not be made up for by the damage a fliping bullet would make.

I wonder if the forces on a solid X type bullet as it was rotating would be strong enough to bend it?

kciH · « **Reply #10 on:** February 20, 2006, 05:38:16 PM »

JJ,
the Scirocco II is out now. Swift claims it is the same internally and externally but that it now retains upward of 80% of it's weight. If the jacket is the same thickness and the same amount of lead it must be a change in the bonding process or a core made of a harder alloy I would think.