I have noticed that the final third of my barrel (Tikka M55 .308) is substantially tighter when running a jag through. I have tried Forest Bore Foam and Pro Shot Copper Solvent 4 several times and left them in the bore for several hours at a time to remove any copper fouling - all to no avail.
Today, amongst other items, I bought some JB Bore Cleaning Compound but now I'm unsure weather to use it or not. I know when using it to never exit the muzzle as it will round it off and destroy the crown but I would like to know any recommendations or experiences with this compound from others?
I have read on the web that some Tikkas of this age may have had a tight final third towards the muzzle as this was a trial for increased accuracy that never caught on - but this was restricted to .22LR and never .308 apparently.
Any thoughts, experiences or advice will be gratefully received!
I should add that during loads development I found Lapua Brass, BR2, 43.5Gr of RL15 and a SMK 175 to shoot 0.48" 5 Shot groups but always had the occasional flier to ruin the group (which after several groups I now wasn't me).
Thanks in advance gents.