hiya NT, all
it's 40mm or about 1 and 3/5ths of in inch.
I haven't profiled or 'waisted' the stock at all so this is a uniform thickness. Just weighed it all up, scope and moderator etc and it's 4.8kg or about 10.5lbs. I quite like the weight as, somewhat oddly, I enjoy standing, unsupported shooting over bench shooting. A bit of weight steadies the shot but can become tiring to hold - more exercise and stamina required!
Balance point seems just in front of the trigger guard.
Slight school boy error as I didn't make the small 2mm inlet in the stock to allow the magazine to slide into the slot
Chrono'ed it yesterday and I'm only at 8ft/lbs so the new Reg needs dismantling and the pin reversed a la Roald but I need to wait on the pressure rated sealant to reassemble before I start that rework. I can only find one UK stockist (Farnell) for Permatex sealants and they have a minimum £20 order value so this might be a long wait!
I can still plink away quite happily with the current power and as I don't hunt with it no power worries there.
It wouldn't win any prizes for beauty, elegance or craftmanship but it solved my problem of dismantling from the stock without removing the bottle & Reg so I'm pleased all round. It does attract a bit of attention when folks see it and you get to talking about what it's based on and what you've done to it!
As a small tip and for comment, now if I want to remove the bottle and/or Reg I prefer to knock out the rolled pin and remove the barrel.
rgds and enjoy your modding.