I believe there is an upgrade Google Doc on this thread with all the common upgrades/options if you have a little search for it. If you can't find it give me a shout and I'll try and find the link.
Welcome to the party.
I'll keep you posted Dave as soon as lockdown does one, next game for me is the 5th at adrenaline Airsoft near Richmond north yorks but I may be able to borrow a field before then.
My general impressions of the Autobot on a standard TM 'two-fiddy' is that as has been mentioned previously somewhere the diamond mound/patch? Sits tight to the start of the barrel, almost flush with it. Additionally it is very easy to clean (probably due to the lemon colour) as I run a cotton bud (q tip for our colonial brethren) over the mound to remove all the propane gunk off of it.
Rapid groups at that range spread to 100mm but a carefully shoot group is around 40 - 60mm in no wind with the rif clamped in a home made Frame using a very lightweight hao bolt TM weight and GnP buffer weighing in at 146g which kept recoil to a bare minimum.