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View Full Version : Sierra Pro Hunter 8mm 175gr Jacket Separation


meaty-btz
07-29-2012, 3:52 PM
As the title says. Just a note for those of you using this one as this has been pretty much the only bullet locally available besides self casting. While mining today I found every single bullet the jacket had separated from the core and I have only found a few of the cores. The few found cores show little deformation except from striking rocks or such under the dirt.

I don't know how I feel over all about this fact, except that it's a bad thing. It isn't just a piece of the core comes free, it is the entire core, intact comes free and the jacket peels back with the core traveling 6-12" further.

Unfortunately my berm has never seen any other rifle rounds besides a .17 HMR of which I recovered them un-deformed (except those that fell through my mesh).

I feel that I should not be getting such clean jacket/core failure and it is the only bullet in my berm that shows that behavior. It also is the only rifle bullet. Is full jacket separation on braking common in large bore rifle rounds?

wtkaiser
07-29-2012, 5:25 PM
Well....if all you do is kill paper, what's the difference? If you want to know how it performs on animals large or small, shoot animals large or small. Don't try to second guess a bullet's performance in one medium by another. There are too many variables.

meaty-btz
07-29-2012, 5:35 PM
Well....if all you do is kill paper, what's the difference? If you want to know how it performs on animals large or small, shoot animals large or small. Don't try to second guess a bullet's performance in one medium by another. There are too many variables.

A good bullet should not have jacket separation under any deceleration other than that which would be destructive to both core and jacket. Basically shows there is no bonding between core and jacket to get clean separation.

Noonanda
07-30-2012, 1:17 PM
A good bullet should not have jacket separation under any deceleration other than that which would be destructive to both core and jacket. Basically shows there is no bonding between core and jacket to get clean separation.

gotta disagree with you, I have seen this before with multiple bullet manufacturers and calibers, has nothing to do with the bullet and has to do with the medium you are shooting into. Dirt is harder that flesh, so the comparison is not there. that would be like saying you should not have core separation or deformation when shooting steel vs Flesh. Apples and oranges

FLIGHT762
07-30-2012, 6:22 PM
gotta disagree with you, I have seen this before with multiple bullet manufacturers and calibers, has nothing to do with the bullet and has to do with the medium you are shooting into. Dirt is harder that flesh, so the comparison is not there. that would be like saying you should not have core separation or deformation when shooting steel vs Flesh. Apples and oranges

I have to agree with Noonanda.

A good bullet should not have jacket separation under any deceleration other than that which would be destructive to both core and jacket. Basically shows there is no bonding between core and jacket to get clean separation.

Sierra Game Kings and Pro Hunter bullets have a very good reputation for cleanly taking a lot of game all over the world. Just because a bullet jacket separates from it's core it doesn't mean the bullet isn't lethal. Sierra doesn't have a line of specialty game bullets similar to bonded cores, partitions or solid copper shanks. They've done a lot of research on what velocities work for their bullets. If you don't want to use them, don't.

I've read many anecdotes about Sierra bullets separating from their cores. Many of the stories note the bullet was found just under the hide of the opposite side with the cores separated. Did the bullet work as needed? Most all of the time, the answer is yes.

meaty-btz
07-30-2012, 7:33 PM
I have to agree with Noonanda.



Sierra Game Kings and Pro Hunter bullets have a very good reputation for cleanly taking a lot of game all over the world. Just because a bullet jacket separates from it's core it doesn't mean the bullet isn't lethal. Sierra doesn't have a line of specialty game bullets similar to bonded cores, partitions or solid copper shanks. They've done a lot of research on what velocities work for their bullets. If you don't want to use them, don't.

I've read many anecdotes about Sierra bullets separating from their cores. Many of the stories note the bullet was found just under the hide of the opposite side with the cores separated. Did the bullet work as needed? Most all of the time, the answer is yes.


I don't doubt the bullets would work. The damage is pretty intense in every case of testing against hard and wood of varying density.. explosive even.

The fascinating thing is the the separated cores are un-mushroomed, even when used against hard impacts like brick or the core turns into a penetrator. I have yet to actually get deep enough to get more than just a few cores, the cores all show no deformation except strike damage. Very interesting. I will get some pictures. It may be an 8mm thing, the bullets are probably not designed for 8x57 lower velocity, considering the same bullets are used for 8mm magnum. I might actually not be getting enough velocity to get expansion so when it brakes in the dirt the jacket being pealed back allows the core to turn into a sabot. I found what I believe to be the brick core based on the red brick fragments found near it. Undeformed from breaking 2x standard red bricks.

Definitively more than just meets the eye here :)