Reapers Airsoft got this review of the licensed KWA HK417 A2 Gas Blowback Rifle by Umarex. Just turn on your video player's language caption as this is done in German... "Good Morning ! Today there is a GBB in review / test, the new HK417 from KWA / Umarex. The gas blowback scores with a very high-quality workmanship and also the high weight and the full recoil could convince. At Internals, KWA attaches importance to durability, because all the relevant components are made of steel. The gas system runs nicely round and seals very well. Negative much of the high gas consumption and associated cooldown on. Also about a NPAS to adjust the energy we would have been happy. In conclusion, unfortunately, we have to criticize the HopUp, which has hardly worked on my model, and thus the knocks out of the box is not playable. If your model runs better here, I would be glad about feedback."

There is an update here regarding the hop-up:

"Gentlemen, as promised there is a small update to the KWA HK417 A2 GBB today. By adjusting the HopUp Tensioner Hopt the Airsoft now clean 0.30g BBs. The range amounts to an estimated 50m and is therefore easy to play. Thanks again to Schnazel for the problem solution."