i would save my money and get a viper tech....one of the best gbbrs you can get that is based off the WA design and viper is cool and improved on the nozzle design aswell the buffer lock area going real steal design with that......but since im to impatient to save up 700 bucks i bought a magpul woc for 220 bucks and put 75 bucks in steal upgrades and now its running good