Home Forums Hunting & Shooting Ask The Gunwriters Ask John Barsness Questions About "BONDED BULLETS"

"Within the structural limits of a given bullet, the lower the impact velocity the less penetration and expansion, and the higher the velocity the more penetration and expansion"

Less velocity = Less Penetration. Really?

Tundragriz fell off his soap box

In your search for a one liner response you missed the point and fail to recognize the engineering difficulty of maximizing the velocity range over which a bullet reliably expands.

John,

Nice article but I am dissapointed that they closed the Bonding Board in Kansas City.

They were also the people that certified the stuff that keeps fillings from falling out of teeth.

I bet George Soros was behind this.

I bet George Soros is behind everything....

I have been testing bullets for years and I am aware of the challenges that bullet designers face, I have just never heard anyone state that lower velocity means less penetration? I have seen th
e exact opposite. I am curious.

I have been testing bullets for years and I am aware of the challenges that bullet designers face, I have just never heard anyone state that lower velocity means less penetration? I have seen th
e exact opposite. I am curious.

So for velocity's within the structural limits of a given bullet (AKA the bullet is not going so fast as to explode or so slow as to not expand at all) you're claiming a lower velocity results in greater penetration through a given medium. Is that right? I just want to make sure I understand your claim.

Less velocity creates less expansion. Less expansion creates less frontal area which creates less drag which results in more penetration. Look at the pictures of bullet expansion at different speeds on the new Nosler bullet boxes. Easy to visualize the different penetration.

Slow lead bullets the buffalo hunters used would penetrate several feet in a buffalo. At the Battle of Adobe Walls, indians were killed by Sharps bullets that were fired through huge stacks of buffalo hides many feet thick that the attacking indians were using for cover.

I once had a 150 gr deer bullet from a .308 Win blow up completely on a deer's rib at less than ten yards. My .38 pistol would have been more effective on that shot at that range. The same deer bullet would probably have 'over penetrated' the same deer at 500 yards. A .22 LR bullet that doesn't deform will penetrate over 12 inches of lengthwise jackrabbit. In general, higher velocity means less penetration. To expect a bullet to expand the same at differing velocities is not usually going to happen.

I tend to agree that lower velocities can cause a given bullet to penetrate deeper, not higher velocities. That's because a given bullet may well expand wider when impacted at a higher velocity or even come apart.
But I've seen exceptions of this too. The Nosler Partition, for instance, tends to penetrate very deeply if the impact velocity is so high it's petals are folded back against the shank or sheared off altogether.
So, it depends on the bullet.
I'm not a big fan of most bonded bullets because I favor penetration over wide expansion. But, even here, there are exceptions. For the first time in many years I just bought three boxes of factory premium ammo for hunting. That's because I've got a raging case of the hots for the Federal Tipped Throphy Bonded bullet. E

I think it was Gary Schiuchetti (sp?) that showed the partition had similar penetration at high and low impact velocities. IIRC the early barnes bullet performed similarly.

The basic rule is that the more a bullet tends to expand consistently to a certain shape, the more it penetrates at higher impact velocities. I've found this to be generally true of Barnes X's, Nosler Partitions and E-tips, Trophy Bondeds, North Forks, etc.

When a bullet tends to expand more widely at higher impact velocities, the less it will penetrate. This category would include Hornady Interbonds, Norma Oryxes, Speer DeepCurls, Remington Core-Lokt Ultras, Swift Sciroccos, Woodleigh Weldcores--and even, to a certain extent, Swift A-Frames, because the rear end also tends to expand at high impact velocities. Also inclused would be cup-and-core bullets.

These "rules" aren't hard and fast, because other factors affect penetration. But in general the area of the frontal mushroom affects penetration more than weight retention, as well as impact velocity.

I understand what you are saying, that penetration is less when velocity is high enough to cause the bullet to come apart or explode. However, that's clearly not what I was talking about being that I prefaced my sentence with �Within the structural limits of a given bullet�

Look at the examples of the Swift Scirocco II bullets in the lower right of this image.



Given the design of the Scirocco II you can see that it's well expanded at 2100 fps and yet holds together (high weight retention) to +3200 fps. You can bet the same weight and caliber Scirocco II bullet fired at 3200 fps penetrates further than when it's fired at 2100 fps into the same medium as the frontal area is nearly the same within this velocity range. That's the hallmark of a well designed bullet like the Scirocco II, a bullet that I doubt could be produced without bonding the lead core to the copper jacket.

Just for fun, here is one test from Richard Mann's websight of a test he did in wet newspaper. I'm not saying it proves anything, but notice how little difference there is in penetration between the .308 Win at a much higher speed than the 30-30.


LOAD




PENETRATION

EXPANSION



.264 Win. Mag. 130 gr. Swift Scirocco II, 1810 fps

22.00 +

0.37



.308 Win. 165 gr. Trophy Bonded Bear Claw, 2700 fps

14.25

0.65



.30 Rem. AR, Barnes 110 gr. TAC-X, 2880 fps

14

0.55



.243 Winchester, Barnes 85 gr. Tipped Triple Shock, 2900 fps

11

0.47



.30-30 Win., 170 gr. Nosler Partition, 2165 fps

10.25

0.63

I am trying to find some data using the same bullet at different speeds, which will be more useful.

Thanks, MD. That clarifies the issue nicely. E

Concerning the Tipped Trophy Bonded, it has been my experience that handloaders (and their stories/reports) are the ones who generate demand for boutique bullets among non-handloaders.

When the handloaders generate a "buzz" for a bullet, all the factory ammo users want in on the action. Selling to both fraternities gains exposure in two different markets at once.

I don't think pure factory users ever generate enough "buzz" to make handloaders try factory ammo (E. excepted in this case).

If the TTB is soft up front with ready expansion, it really does seem like about the best of all designs to me, but I'll probably never find out with the price they ask for factory ammo.

I've used the Tipped Trophy Bonded some, including taking my biggest elk with it, and have mentioned it here and there in various articles. So have some other gun writers.

But the bullet has run into other problems, though it works great. First, there are some gun writers and hunters out there convinced that only the ORIGINAL Trophy Bonded was any good--which has not been my experience, by a long shot. Second, the nickel plating makes some flat-earth type reloaders suspicious. Third, the component bullets were expensive and not easily available--and competed directly with some already well-established brands, such as the Barnes Tipped TSX and at least a couple of Nosler bullets. Fourth, they may have even suffered because some other hunters firmly believe that bullet quality is directly related to price--and there are some even more expensive "boutique" bullets out there.

All of which shows that it's difficult to wedge a new product into an already crowded market, especially in a slow economy.

Are they soft enough up front to get FULL expansion down to 2000fps?

The other thing, or things, about the Trophy Bonded bullets/ammo is their popularity with the LEO and military tactical sorts.
Some time back, an extensive search was launched for a load that LEO/military snipers could use that would stay on course when passing through things like angled window glass. Conventional match ammo, whose bullets had alot of their weight in the rear of the bullet will not stay on course when passing through such barriers. But the Throphy Bonded ammo was found to stay on course when such things were encountered. To my knowledge, it's the only bullet design that does. For that reason, they are carried by such people for such jobs.
The latest ammo, is alot more accurate based on my limited testing.
As a hunter, anything that will help me make a proper hit on an animal is worth having. I've had a few shots go bad because of branches, or twigs that I wasn't aware of. This bullet may not work perfectly if this happens, but it's apparently has at least some ability to do better. E

Can I kindly request someone post the article so it can be read. I requested a link on 11-07-11 at 11:03 AM and I still can't seem to get the article. I would love to read it.

I would also like the CF to figure a way this doesn't happen each time there is a great article.

Happy Holidays