WE-999c downgrade to 350fps, which spring m90 or m100?

[sqrson]

Hi guys,
Total newbie here, who just purchased his first 'proper'ish rifle - WE-999c. It states to shoot at around 390fps out of box, so I will have to downgrade it to 350fps for most sites. I have been told that I will need an M90 or M100 spring, but not sure which one would be closest to the 350fps goal. I know safest bet would be the M90, but dont want it to be under powered if its too weak. Any advice much appreciated
regards

[minisam92]

Re: WE-999c downgrade to 350fps, which spring m90 or m100?

some guns are way over and very hot out of the box bud , if you can shoot a few bbs through it then chrono it if you an to see where your at to start with

[sqrson]

Re: WE-999c downgrade to 350fps, which spring m90 or m100?

good point, will wait for it to arrive and check the power first. Thanks