I did a full tear down yesterday on my 22 year old 10/22 and had the parts in my hand.
You may be ablt to polish the hammer and the sear as well as cleaing the trigger group of all the gunk may help. You know all the greese mixed with unfired powder, dust, and field debris.
Total time of tear down and clean was about an hour. And I took everything apart cleaned it all and reassemblled it in that time.
But if your looking for target crisp I +1 everything about the drop in parts.
Mid south, midway, cabelas, gander mt, or brownells should have any 10/22 parts you may want to trick out your gun how ever you want.