barnes expansion threshold

[fz1boxer]

trying to find out what the minimum velocity is for the tsx bullet.
found some 7.62x39 with a 123 grain tsx projectile.
if its 2000 fps thus shortening effective range i would pass.
1500 fps would be a different story.
i e-mailed them a week ago and so far no responsse.


got my answer but it wasnt from barnes

[WS6]

trying to find out what the minimum velocity is for the tsx bullet.
found some 7.62x39 with a 123 grain tsx projectile.
if its 2000 fps thus shortening effective range i would pass.
1500 fps would be a different story.
i e-mailed them a week ago and so far no responsse.


got my answer but it wasnt from barnes

-1800fps for the 70gr TSX
-1900fps for the 55,62 gr TSX
-The "non 5.56" 50gr bullet (handloading component) is also 1900fps
-The 5.56 loading by Black Hills using the 50gr Barnes has an expansion threshold of 2300fps, as it is a tougher design meant for use at close ranges against windshields, etc.
-300 BLK 110gr Blacktip has an expansion threshold of 1300fps. The blue-tip 110gr .308" dia TSX bullet has an expansion velocity of nearly 500fps higher, as it is meant for other cartridges, if you will.

Hope this helps. If anything it proves that you need to know the EXACT bullet beign discussed, and "transposing" expansion velocities doesn't work with the Barnes. It's very very VERY caliber/loading specific.

[fz1boxer]

thanks that helps quite abit,as i have other loadings using those projectiles.
i knew the 5.56 50grain load was a heavy duty construction and had a high expansion threshold but never knew what the 70grain tsx in 5.56 was in fps.

[dabbie]

and if it does so,(in flesh) then it's likely to just fragment at higher velocities. That's a very low velocity to get a spitzer hp to expand. Even 1500 fps is normally too low for anything but a varmint hp to expand reliably in flesh.

[fz1boxer]

Barnes has it figured out,the construction of the projectile is what lends itself to expansion at lower velocities and the ability to stay together

[WS6]

and if it does so,(in flesh) then it's likely to just fragment at higher velocities. That's a very low velocity to get a spitzer hp to expand. Even 1500 fps is normally too low for anything but a varmint hp to expand reliably in flesh.

This is why I'm switching over to 300 Blackout in barrels less than 14.5".

[dabbie]

gel moves into and out of nose cavities a LOT better than organ tissue, especially the lungs. plus, it's easy to fake pics. That's an awful lot of penetration for what amounts to a 9mm (weight of the .300, 1300 fps) I very much doubt that you get that much penetration if it expands. /Somethings is wrong with this picture.. and the whole point of the Blackout, really, is subsonic loan thru a suppressor. 1000 fps, not 1300 fps. if you go supersonic, you are just lugging around a lot more weight, spending a lot more money (vs 223) throwing away any chance of re-supply from standard stocks or friendly troops, and losing the advantage of being able to quickly swap to and practice with the .22 conversion unit

[WS6]

gel moves into and out of nose cavities a LOT better than organ tissue, especially the lungs. plus, it's easy to fake pics. That's an awful lot of penetration for what amounts to a 9mm (weight of the .300, 1300 fps) I very much doubt that you get that much penetration if it expands. /Somethings is wrong with this picture.. and the whole point of the Blackout, really, is subsonic loan thru a suppressor. 1000 fps, not 1300 fps. if you go supersonic, you are just lugging around a lot more weight, spending a lot more money (vs 223) throwing away any chance of re-supply from standard stocks or friendly troops, and losing the advantage of being able to quickly swap to and practice with the .22 conversion unit

Gel simulates muscle, not lung tissue.
Nothing fake about it. It performs similarly on game.
The purpose of 300blk is not just subsonic, and never was.
I don't have "support" or "friendly troops" unless you mean Midway and my bank.

[bzdog]

gel moves into and out of nose cavities a LOT better than organ tissue, especially the lungs. plus, it's easy to fake pics. That's an awful lot of penetration for what amounts to a 9mm (weight of the .300, 1300 fps) I very much doubt that you get that much penetration if it expands. /Somethings is wrong with this picture.. and the whole point of the Blackout, really, is subsonic loan thru a suppressor. 1000 fps, not 1300 fps. if you go supersonic, you are just lugging around a lot more weight, spending a lot more money (vs 223) throwing away any chance of re-supply from standard stocks or friendly troops, and losing the advantage of being able to quickly swap to and practice with the .22 conversion unit

Not sure I follow your reasoning. The 300 BLK Barnes 110gr bullet was designed to be barrier blind. That's it's thing. The chart posted by WS6 specifically includes barriers, not just bare gel. Not quite sure why you'd doubt the measurements.

car door test:
http://youtu.be/9mXa5AiT0r4

The Barnes 110gr is the killer app for the 300 BLK IMO (no pun intended). It's light enough to have good velocity, has reliable expansion through a variety of media, has excellent penetration. With a muzzle velocity of 2350fps, this isn't similar to a 9mm handgun round*. The actual only problem IMO is that it does have a lot of penetration and in some cases that can be undesirable.

As WS6 notes, each of these Barnes bullets has different operating envelopes (both upper and lower velocities). Optimally you should run the specific bullet within it's envelope for good results.

The OP is a bit fuzzy about exactly what he is looking to do, but mentions 1500fps, so it doesn't sound like a subsonic application.

-john


* Unless we talk subsonics and these Barnes rounds are not designed for subsonic use.

[fz1boxer]

i was debating making the cross over to 300blk with it being backup to 5.56.
i have 7.62x39 and could never find anything loaded with a barnes tsx projectile,until i found it i was prepping to switch to 300blk.
going subsonic was/is not a direction i was going with the 300blk.
i was looking at effective barrier blind rounds in 7.62 with what i already have,7.62x39 and 5.56.
i also wanted expansion thresholds low enough i would not be range limited on 7.62x39.
250m vs 100m