Re: Steel Core Penetrator bullets
They wont wear your barrel any more than a normal bullet will. The steel core is internal. It is the part outlined in red in the image below. Note that it is still encased in a copper jacket.
The SS109 is the Belgian (where it originated) designation for the actual projectile. The NATO standard version of the round is M855. It is 62 grains and works best in at least a 1-in-9 twist barrel. The faster 1-in-7 will work as well. It has a somewhat negative reputation among U.S. troops engaged in current conflicts because it is designed to penetrate old soviet helmets and body armor. It doesn't fragment in soft tissue as easily as the older M193 (55 grain), or the newer Mk 262 Mod 1 (77 grain).
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