A few questions about my No. 4 Mk1*

[CINDERS]

If you look closely in the pic with the front band you will note the top wood is contacting the front sight block this will play havoc with your accuracy, you can put some packing under the band into the slot on the top band so it exerts a bit of pressure I use Balsa wood another trick is slivers of this between the two pieces up front and I do mean thin.
I use this on my 4's the balsa is cheap to replace and 1 small sheet will last a long time, after a while replace the slivers as it does compress but it will stop the top wood from moving forward and wrecking the accuracy there is another way that was described in a book but it involved putting a centre pop on the front and rear edge of the band so it went into the recess to stop the top wood from moving to far forward but I prefer the less invasive action using balsa.