I've used one. If you learn to shoot a 3 shot burst they're great guns. If you're going to shoot it full-auto much then put the bipod on and the added weight up front helps hold it down. I also liked the HK 21 rear sight better.There might still be an after market thick soft rubber butt pad available, makes it easier on the shoulder. The HK doesn't shoot much better than a stock M1A but it does shoot better when the gun is really dirty. The big draw back is that the HK tears up brass more. you'll loose more cases and get fewer reloads. Oh, the G3 doesn't lock back on the last round. I'd load the next to the last round a tracer round and stick in a fresh mag with one round still in the chamber.