I was in the NRA office at Bisley on Saturday and on the notice board in large print Do Not use any heavier projectile than 144gn Nato round in No4 conversions damage will result. I think that advice would extend to the Indian 2a, 2a1 as well. That Indian proof load test is the same as the current proof test used in the UKicon test. One dry @+ 25% one oiled @ + 25%