Okay thanks for clearing that up for me - no shock buffs, thought as much.
The reason why I have employed a shock buff is that I was experimenting with 147 gr JHP projectiles, over 3.6 gr of N320, and did not want to damage the gun in recoil if the spring was too light. Intended on leaving it there for security sake, and did not want to brake the rules.
I have the understanding under the rules that main recoil springs could be replaced, and that in doing so I have reduced the recoil spring to 10lbs.
Are you saying under Rule 19, 20 fitting recoil springs of less then OFM issue spring weight are not premitted in Production? If so then I will need to reflect on this carefully when working up loads - presumably so will many others.
Any advice gratefully received as I obviously an knew to this