I'm relatively new to airsoft and i want to upgrade my G&G GR15 raider CQB. So i bought a Aimpoint style red dot sight only to find out that the triangle sight on my GR15 blocks the sight, rendering the sight useless. Unfortunately G&G GR15 triangle sight aren't removable, So my only option is to get a new outer barrel. I looked around and found the http://www.evike.com/product_info.php?cPath=25_101_277&products_id=40017 I emailed evike to see if it would fit and i got told that it should fit it however it wouldn't allow the barrel nut to fit properly, and they way to get around this is to buy a new RIS. I have taken the RIS assembly completely off, including the barrel nut, and i dont see why an aftermarket outer barrel would not fit. Can anyone confirm what evike said, or an aftermarket barrel would fit fine?