i took my SKS completely apart today for the first time to clean it really well, and everything went perfectly according to the guides i have seen, until i went to put the trigger group back in. the hammer is cocked, the safety is on, but the thing just won't lock back down. the magazine is seated right, i lined up the notches and everything - ive tried sqeezing it to lock it down, leaning on it, i even leaned the rifle against my big work desk and put my weight on it, but nothing has worked so far. most of the guides say you just use firm hand pressure and it goes right in, i saw one mentioned using a clamp to help, but i cant imagine it possibly taking any more pressure to get it back on. any ideas of what i can do to get my gun put back together? any help is greatly appreciated