Alumyx posted last month a "lightweight" Silverback SRS-A1 airsoft sniper rifle. He also listed the parts he used in this custom work some parts use Carbon Fibre and the lightened parts and achieved a total weight  1.725Kg naked/2.365 kg with scope & magazine. If interested here is the list:

Video from Silverback Airsoft showing how to assemble and fine tune your Variable Mass piston for Silverback SRS-A1 pull bolt... "Available at authorised dealers, the Silverback SRS Variable Mass Piston - Pull bolt will enable you to customise your piston weight from the standard piston."

Alexander tells how they tuned the Silverback Airsoft SRS-A1 to 170m/s in this Red Army Airsoft video... "In this issue, we will be tuning the SRS-A1 spring sniper rifle from Siverback Airsoft. We test two 13mm VSR springs of the M160 and M170 type. We test the steel guide with Teflon tube and bearing for a better setup. We'll put a new rotary hop-up with a quick adjustment. We'll install a new trigger with adjustments to the landing height and a finer adjustment of the free wheel."

Alexander of Red Army Airsoft sends in news that has a new video and it's about the Silverback Airsoft SRS-A1 Sport... "The Silverback SRS-A1 airsoft sniper rifle replicates the combat prototype, not only in terms of appearance, markings and dimensions, but also in terms of design and even materials for the manufacture of external parts."