Well with an 18" barrel on a Mosin, you wouldnt actually have to HIT your target, the bullet would be superfluous as the flash and burning powder would annihilate anything within range... Try one of the M44s or an M38 at dusk to see what I mean- and those are 20" bbls. If I shot my M38 as something other than recreation, a flashhider would be great! As it is, I have an M91-30 with the 29" bbl.. that long barrel eats up most of the flash and recoil. YMMV
I really really like your Icon.. GAC has been one of my heroes since childhood.