No 7 mainspring?

I've just had a lovely No 7 Mk I made up for me.
[[Prompted by Alan's post below, edit added: it's the BSA rifle, not the Canadian one]].
I'd like to improve the trigger pull, which is a bit heavy. The mainspring is a cut down No 4 spring, which I understand was often used. Closing the bolt is also quite stiff, and I wonder if the stiffness of the spring is putting pressure on the sear, and causing the heavy trigger. I wonder whether there should be a more compliant spring in these rifles?
Does anyone have a No 7 and could tell me about the spring - what is the diameter of the spring wire, how many coils does it have, and what is the unstressed length?
If nobody has a No 7, then how about a No 8? This also has a short striker and may be similar.
I would appreciate any advice.
thanks
Rob

I assume you are referring to the No7 Mk1 (BSA) rather than the CNo7 Mk1 (Long Branch)

I am away on my boat for another month or so, but if you don't get the answer in the mean time, remind me End September / Early October and I'll gladly measure mine for you.

I am likewise away from my No. 7 for another week or so, but should be able to help out. If you don't hear back from me by the end of next week feel free to give me a reminder!

The No 7 mainspring and trigger pull are all sorted out now, both lovely as a result - many thanks to all who helped.