longest spring use?

[RT77]

When should I try to run my mag with the longest spring on my bolt for my x-valve, the reason I asked is I'm using the red or middle size spring now and it works great but my velosity is all over the place jumps from 10- 25 fps difference. Do you think changing to the longest spring will help.....my ball to bore match is perfect.

[Bad_Dog]

your velocity problem could also be from unconsistant paint to barrel match. If you're using small paint with a large bore barrel, the velocity will tend to jump around. Likewise if you're useing cruddy paint which doesnt have a uniform size to it, some paint will be smaller... and some larger, your paint to barrel match once again wont be very close and since some will fit well, others not, the velocity will jump all over the place...

[Dayspring]

Are you using the RT chrono procedure?