Which airsoft gun is better??10 points?

I wouldn't trade. Your gun is better and you would have to get the m4 upgraded to make it better. The only way I would say go for it is if you prefer m4s over sigs. If you really want to get an m4, you should probably just buy a different one. I'm not bashing your friends credibility, but he could be hiding something thats wrong with the gun, so I'm not sure that I would trust the deal and I probably wouldn't trade. Your gun's probably worth more than his, so it probably would't be an even trade anyway. I'm not an expert on either gun, but this is all I got.