I Didn’t Expect This: 10mm Chaos in the FPC and the Pistol

Today we put the Underwood 155gr XTP in 10mm to a true side-by-side test—fired from both the Smith & Wesson M&P 2.0 10mm (4”) and the Smith & Wesson FPC 10mm carbine. This is a load I’ve seriously considered for a get-home or defensive setup, so it’s time to see how it actually performs in ballistic gel, on the chronograph, and on paper. Using my standard “real-world” test setup—denim and T-shirt layers, clear ballistic gel, and medium-density fiberboard—we evaluate penetration, expansion, fragmentation, and velocity. Out of the handgun, the 155gr XTP behaves exactly how you’d hope from a hot 10mm defensive load. Out of the FPC, however, velocity jumps into the ~1800 fps range—and the results get wild, with violent expansion and limited penetration. This video highlights why ammo selection matters by platform. A round that works beautifully in a handgun may behave very differently once you add carbine velocity. If you’re running a 10mm pistol/carbine combo, this test gives you real data to decide whether the 155gr XTP belongs in your loadout—or if you should be looking at heavier bullets. Unfortunately we experience our first failure with the S&W MP 2.0 10mm. Not a good sign. ‪@MCARBO‬ Help support the channel by becoming a channel member. Channel Members enjoy early releases and member only content. If on an iPhone, use the link below to join the channel otherwise hit the join button!    / @triggerbarphd   #10mm #underwoodammo #155grxtp #ballisticgel #geltest #mp10mm #smithandwessonfpc #carbinevs pistol #handgunhunting #terminalballistics #chronographtest #selfdefenseammo #woodsdefense #clearballistics #gunchannel #firearmtesting #triggerbarphilosopher #ammunitionreview #10mmfail #sw10mmfail #mpfail