First off, this is the best gun I have ever had. I have had it more than a year and a half. Absolutely recommend it to beginning snipers.
This gun is very suitable to upgrades. For me, it shot 377 fps with .23 gram bb's before I upgraded the spring. There are 'mods' you can do for free (google teflon tape jg bar-10). Stock this gun shoots best with .23 bbs. Make sure to take it apart and clean it when you get it. Learn your gun before you even fire a shot. I don't recommend the bipod the picture shows (mine didnt even come with one, or the mounts for them). You can find a metal bipod and sling mounts at walmart.
There are some bad things about this gun though. The sears wear out if you upgrade the spring too much, the barrel came bent with mine (not airsoft GI's fault, i didnt get it from them) The rear sight sucks and you have to mount the front sight yourself. It's a sticky sight so it's hard to get off if you want to add a scope.
I suggest buying new screws. The ones that come with the gun are stripped or strip easily. Remember they are metric, however standard miniature screws (cheese head Phillips) work great in most places such as the hop up chamber and trigger assembly.
After awhile plastic parts wear and the gun will start shooting 2 shots at once. To this I have not found a solution.
Best Sniper for $100, easy for starters and will carry you to the advanced level.
Hard to pull back with heavier springs (deal with it)
Plastic part in hop up that is hard to find.
Rating: [5 of 5 Stars!]