Poor Man's Ballistics Testing of Subsonic 300 Whisper Load

[buffetdestroyer]

I apologize ahead of time for a lack of photos.

So I have been worried about a few things regarding ballistics with my Whisper in subsonic mode. The first aspect I was worried about was penetration (too little, too much) and the second being wound channel.

Since I see people belittle this cartridge on other sites, I wanted to test for myself to see how effective this round is when subsonic compared to results I had seen with handgun rounds that are designed to expand. However I don't have access to ballistics gel and a temperature controlled indoor range.

So I decided to test the wound channel with watermelons and penetration with gallon water jugs similar to what I have seen in the "Box o Truth" website.

My test equipment is
2 - watermelons (seedless - ripe and delicious) about 12" wide by 17" deep
8 - One Gallon jugs of water that are 5" wide and 5" deep
Loads of 220 Grain Sierra Matchkings with 8.5 Grains of 2400 on a 10.5" barreled AR upper with a 1 in 8 Twist and an HTG M30A suppressor.

Wound Cavity Results:

The results of the wound channel in both watermelons gave an entrance hole of .3", which is to be expected. The watermelon from about a third of the way through blew out the back completely shredded into sweet mushy bits of pink goodness. The wound channel in the first third of the watermelon was about 1" in diameter creating a permanent wound channel of 1" before the temporary cavity blew out the back end. This leads me to believe that the bullet tumbled about 4-5" into the watermelon.

Penetration Results:

The second setup I did 4 bottles deep for a total of 20" of water to penetrate.

The first bottle had 30 caliber holes front and back and drained very slowly for both tests. This is supposed to be equivalent to about half the distance in ballistics gel or 2.5". The second, third and fourth bottles exploded violently and the exit of the second bottle looked like a "V" which means that it tumbled. The third bottle of the first shot was shredded as was the fourth. Entrances were all similar to the "V" and on the second test, the last bottle wasn't split as the third bottle was.

My wife recovered the bullet from the second test about 4 feet away from the last bottle. The bullet looked to be reloadable and had no deformation whatsoever.

Conclusion:

This leads me to believe (again - this is a poor man's test and the results are not proof of anything) that I get between 10-12" of equivalent ballistics gel penetration with this setup, which is ideally what you want an expanding handgun bullet to accomplish.

The velocity has between 1000 - 1050 FPS depending on temperature conditions and how many rounds I run through the gun. It was about 87 degrees outside when these tests were done (and I didn't have my Chrony to measure velocity on the day of these tests so that is why I have a bit of a large variance).

With only 1000 FPS, the muzzle kinetic energy is between 488 ft.-lbs to 538 ft.-lbs. which is about equivalent to a 45 Auto +P out of a subgun with penetration similar to a successfully mushrooming hollow-point. Of course the retained energy with this bullet along with the inherent accuracy gives a major advantage to the Whisper in my mind.

As a final note, I will say that the rounds were very quiet, but the impact on this was loud (especially the water bottles). I don't think that I could be any happier with the results and I am confident that if I used for animals larger than coyotes, it would still be very effective.
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FORD MTX-75 TRANSMISSION

[i8asquirrel]

Thanks for the info.....sound like it was fun doing also!

[buffetdestroyer]

Originally Posted by i8asquirrel

Thanks for the info.....sound like it was fun doing also!

The watermelon was delicious!
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Ffm College

[Rikky Lee]

Good testing. The inter-web is an amazing place but you cannot believe a quarter of what you read as a lot of it is just cut and paste "instant opinions".

I am a big fan of testing these claims and debunking as required.

The 220 and 240 grain bullets will do a lot of damage. Everything I have hit with my 30BR has gone down on the first shot; sometimes spectacularly and sometimes not. But there is no walking away from what a 240 at 1050fps will do to heavier than air material. (and a 180 SST will expand at subsonic velocities too)

Keep up the good work!

[buffetdestroyer]

My reason for the .300 Whisper is because I wanted a 9mm AR setup for suppressing with the capability of taking larger game like Coyotes and maybe hogs (birds and rabbits are my .22 Upper's forte) effectively and without a sonic crack.

But by the time I got a new upper, mag adapter for an SBR receiver, a new suppressor and the stamps for everything, I decided the Whisper would be more prudent since I already have a .308 suppressor and would reload for the subsonic 9mm anyway.

The accuracy that you get with a 300 isn't in the same league as the subgun 9mm's that I have shot. The 300 is far more accurate and the components are much more prevalent.

This test just set my mind at ease that it wouldn't do the ice-pick wound that I read about from some of the "Internet Experts"!
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VARIABLE UNIVERSAL LIFE INSURANCE DICUSSION

[Expatriot]

I did some terminal ballistics testing with a subsonic 7.62x39 and got quite different results. My test media was wet phonebooks.

I found that even a light 150gr subsonic is capable of incredible penetration. The bullet went through 16" of soaking wet paper and then exited the bottom of the bucket and disappeared into the dirt.

The nice thing about wet paper is you can see the entirety of the wound channel. The bullet's would make nice round holes in the bottom of the bucket meaning they were not tumbling at all.

IMO watermellon isn't a great test media cause the inside is very soft, much softer than flesh yet the outside is quite stiff yet brittle. So they tend to mush and then split much more easily than flesh would.

I realize there are people on this board with actual live animal experience using subsonics but I guess what I am saying is that subsonics can be unpredictable. They may do some damage or they may just poke a hole in the animal.

[buffetdestroyer]

Originally Posted by Expatriot

I did some terminal ballistics testing with a subsonic 7.62x39 and got quite different results. My test media was wet phonebooks.

I found that even a light 150gr subsonic is capable of incredible penetration. The bullet went through 16" of soaking wet paper and then exited the bottom of the bucket and disappeared into the dirt.

The nice thing about wet paper is you can see the entirety of the wound channel. The bullet's would make nice round holes in the bottom of the bucket meaning they were not tumbling at all.

IMO watermellon isn't a great test media cause the inside is very soft, much softer than flesh yet the outside is quite stiff yet brittle. So they tend to mush and then split much more easily than flesh would.

I realize there are people on this board with actual live animal experience using subsonics but I guess what I am saying is that subsonics can be unpredictable. They may do some damage or they may just poke a hole in the animal.

I would imagine that if I used 150 grain full metal jackets, I would get similar results. The twist rate in relation to the bullet weight is the key to the bullets yawing and tumbling, which my test satisfactorily showed me (in two different mediums) the 220 grain matchkings do out of my barrel.

It was results like what you stated (obviously a 7.62x39 is not the same as what I am shooting on multiple levels including magazine, bullet diameter, twist rate, parent case & capacity, bullet weight, chamber dimensions, barrel length etc.), that piqued my curiosity to test and see what MY rifle and load would do because I got my information from others that had done similar tests before purchasing my rifle and components.

Hopefully this helped or inspired some of you, but since nobody else owns my rifle, your results are going to be your results regardless of what firearm, load or medium you use.

Therein lies the problem with ballistics testing - there is no easy way to see what a type of round does 100% (statistically speaking) of the time in real tissue without killing tens of thousands of animals with multiple weapons of the same platform (read the Stasbourg tests and all the controversy about it being a falsified test - and that was supposedly done with goats because they are similar enough to humans). People are still debating .223 vs. 7.62x39 vs. 6.8 vs. .308 for the military because there is no 100% way to tell you what your shot will do before you shoot, even if your setup has been used in countless battles before you pull the trigger. Environmental conditions and shot placement will create enough variables that nothing can be unmistakably foretold prior to the shot.

If you can afford ten thousand 130lb to 220 lb pigs to shoot with a given load under various conditions at various points of impact, I would imagine your results would be far more accurate than shooting watermelons, phone books and water jugs. I can't do that, nor would I waste that much bacon.

However, I am still satisfied with my results and am confident to take my rifle out for coyotes, hogs and even larger game like deer if the State allows suppressed weapons while hunting. I don't like to make animals suffer, nor would I like tracking them. However blowing up watermelons and jugs of water is fun and can be an end unto itself even if you don't draw a conclusion from it!
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EXTREME Q VAPORIZER

[Rikky Lee]

I've found the lighter bullets in the 30BR behave differently to the very heavy ones in media. I would also steer away from using FMJs as an example of high end subsonic Whisper performance in the 7.62x39 and suggest that you try (if it is a .311 bore) some 174 - 200 grain HPBTs or RNs.

150 grains is a good supersonic weight for a bullet - it took me a while to tune a load in for the 30BR - but it has the potential to be a solid performer out to 300 plus yards on targets. The 185 was also a great supersonic load for the same reason.

But for subsonic loads, 200 grain Lapua subsonic or 240 SMK are my choice for hunting as they hit hard and bleed out.