India made a No4 bolt head. It was never one of ours. There were some UKbased trials to ascertain the viability of such a beast but I'll cut to the quick. Regardless of the manufacturer of the body, it was discovered the if a rifle needed a bolt head over a size 3 then the body was worn out to - and possibly beyond - the depth of the hardened locking shoulders. In any case, even a No3 bolthead was not permitted at Base workshop