surefire & harris bipods

Gun Magazine

The weight of the barrel will only refer to whether the barrel is a "heavy" one or not. The heavy-barrel (HB) designation means that there is more metal there. Some of these taper at different points, either underneath the handguards or from the front sight on. The HB whose thickness does not vary (i.e. is maintained from back to front) offers the most durable design. The 16" barrels are available in a lightweight configuration, M4 profile (thin under handguards, thick outside handguards, and with a cutout to allow mounting of M203, and in a heavy barrel. For this rifle, a lightweight or M4 Gun Magazin profile offers the most advantages as far as weight and handling.

mwgsam16