I suggest you take your carbine to a qualified gunsmith. Your description doesn’t suggest any particular problem - getting the clip “to seat firmly” doesn’t say anything. You can’t gunsmith a gun by email. I speak from 36 years of experience handling customer problems with firearms - not gunsmithing them - having to write up their perceived problems for the appropriate gunsmith.
You would have to give a lot more detailed description of what you perceive are problems, and what the results of those possible problems are - is your gun failing to feed - you didn’t even really say that - and if so, a complete description of the position of the cartridge in relation to its correct feeding position. Also, what you mean by “not seating firmly” - most detachable magazines have some play in them once locked into a firearms - that is perfectly normal and of itself not a problem.
I think a firearms forum is a more appropriate place for your question, but that won’t beat showing it to a qualified gunsmith. There are a lot of folks out there that think they know the reason for every gun malfunction, and do not!