On active service I always used to leave my gas regulator fully closed. That way, it'd always re-cock. At a big shooting competition at Nee Soon ranges in Singapore with Aust, UKand NZ
Infantry, the KSLI (UK Kings Shropshire Light Infantry) Armourers told me that they'd balance their rifles to just operate, probably on No4 gas. But I didn't trust it as some of the shoots were timed and you just didn't have time to start faffing around clearing a stoppage on the timed shoots.
After all, gas closed off, the actual RECOIL remains the same. It's the slightly harder kick of the breech block carrier hitting the TMH that gives the feeling of greater recoil. It's not, it's just a bit more mechanical inertia. But wonderful times.
Bruce is right..... Towards the end of their life, some of the L1's were definately getting tired and even short supply that meant some life extending mods were the order of the day. There was one that I remember reading here, that I never saw oor heard of, where the TMH was slightly modified to correct the loose/slack axis pin holes, by ring punching. A totally useless exercise! And spread the sides to do the same. Never saw it but definitely there.