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.
________
FORD MTX-75 TRANSMISSION
Threaded Mode