Originally Posted by Darklen
Bearings are what you might be thinking of. Ball bearing type bushings are designed for high rate of fire (ROF) guns but typically won't stand up to a high fps spring for long. I have plenty of remains of internals in my shop from clients who though otherwise to testify to that. High fps springs should use a good quality solid metal bushing.
Ah perfect, thanks for clearing that up Darklen.
Guardians of Asgaard - KF25 -
Primaries: LCT AS VAL, Real Sword Type 56-2, VFC M4 CQB Mk2
Secondary: Latino heat, TM Glock 17