I think a test on ballistic gel would be interesting.

Maybe those extra 15 grains helped also are they different metals

Possibly bullet shape? I know the extreme penetrators have thicker flutes that the extreme defenders. Better BC of the heavier bullet as well. Interesting results, may have to grab a few boxes for myself and try em out.

In the world of ballistics it’s all about energy. The 115gr round is may be moving a little slower but the weight increase means it’s able to hold on to more energy longer thereby transferring said energy into the vest which is evident by the ripping of the fibers and fully penetrating the armor. Another similar example, have you ever seen a 5.56, 55 grain round completely blow up a watermelon but a 40 grain 22 long rifle only punches a hole thru it. That’s because of energy transfer, the 5.56 is going in excess of 3000 feet per second while the 22 long rifle is only going about 1100 feet per second. The bullets are about the same size but the 5.56 is 15 grains heavier and traveling almost 3 times faster. I know it’s a big jump in trying to explain this but I hope this helps. Stay cool man, I just subscribed.

Its the bullet design in the coding. Also, a little heavier so it helps push through barriers.

I feel that even though the 100 grain bullet didn't penetrate the vest, It still was able to put a lot more energy into the vest providing stopping power rather than going through. I own 100 grain but now after seeing this I want to purchase the heavier grain. Great video man!

Mass in motion. With both projectiles being the same diameter (similiar resistance) weight and speed BOTH make a difference, there is a fine balance where giving up more weight for more speed just doesnt pay off. Just like how a 9mm is smaller and faster but, often, 45acp will actually defeat barriers better. Throw a golf ball at a tent, throw a brick at it. Same principal.

the heavier bullet hits harder even though it travels a little slower.