mine was about 6 months, but i thought i spoiled it, coz it didnt bolt any for 2 months and i thought it might of got a good kick the first time it went down. but then again there may not of been anything down the holes. after the 2 months of not bolting, it turned out to be quality. bolts and digs plenty.
either 2 or 3 backed up, when we dig now.