Hey guys, I had to take my spring out of my rifle to put into my step sons new/used Mb03. It had lots of bad parts so I used my spare parts for him and he needed to lower the spring from his "500fps+ -" So I had to help the kid out and now with his spring I had a dang slamfire,lol.. So now I have a spring thats no good to me and would love if someone had a stock 400fps or so spring they would like to trade or sell super cheap. I already have 2 harder ones. I dont have a chrono but my old spring got me 450-470fps with teflon tape. "Coke can test". I would like to go back to that or lower. I prefer 420 to be actual.