I have read here and on other sites about top hats, power bands, washers and similar materials, often used for tuning. However, there is no ready explanation to be found about the effects these have and their use. It would be helpful if, possibly somewhere on the site - in the form of a 'sticky' perhaps - someone could provide a glossary of terms and a brief description of usage for each device. This would be most helpful for beginners, newcomers to this hobby and technophobes like me.

Meanwhile, I wonder if one of the experts here could kindly explain:

1 What is a top hat and what does it do? I gather it is added to the end of a mainspring. Is the purpose to safeguard the spring and increase its longevity?

2 What is a power band?

3 What effects do additional washers have? On the face of it, adding a washer would surely reduce the air space and sweep within the cylinder and also reduce the compression ability of the spring. That would, presumably, reduce the power of the rifle. However, I understand that washers can raise the power of a rifle. How is this feasible?

4 Does power vary between a heavy and a light piston?

These things are a mystery to me. This site has enthused me since I joined but there are still many things I have yet to discover!

Rgds to all,
A