I have an SCR 11 with JP's med weight 18 inch barrel. LMOS, heat sink and silent spring etc. It is quite heavy, but I wanted it that way since I also use it for long range prarie dog matches (out to 550 yards) since the weight adds stability. I also recently used it a 3 gun match and did not feel that the gun slowed me down at all. JP makes awesome stuff, be warned you will become a life long customer.