I was just thinking, isn't it weird that when comparing .556 and .45 ACP, even though the a 16" .556 has over 3x the power of a 5" .45 ACP (1174 vs 378 Ft/Lbs energy), that the .45 actually has more momentum. Not that that does or doesn't count for anything, but if comparing a 55 Gr .556 and 230 Gr .45 ACP round, respectively travelling at 3101 and 864 FPS, the .556 has a momentum of 3.3 kg x m/s (or 24.3568 Ft/Lbs) while the .45 ACP has 3.92 kg x m/s (or 28.3722 Ft/Lbs).
.556 Ammo is 55 Gr Federal XM-193 and .45 ACP ammo is Speer Gold Dot 230 Gr.
.556 Ammo is 55 Gr Federal XM-193 and .45 ACP ammo is Speer Gold Dot 230 Gr.
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