a buddy of mine has an ar 15 that he uses for coyotes, not my kind of gun, too much springs and crap, so I don't know much about them. almost since day one the gun has had trouble feeding in new rounds, it will always fire the first round without issue, however it may fire one or 2 more then not feed, being out in the field the gun jambed up, so being in the middle of now where I had better figure out something, so I took the gun apart and traced the problem to the bolt not moving freely back and forth in the upper, it seems to kinda hit tight spots in the surrounding bolt raceways, so I took a little motor oil (all we had) off the dipstick of the truck and this seemed to almost fix the problem, had I put more on there it would have done alot better. is this area supposed to have oil on it?? what might I do to fix it if not

Yes, the bolt carriers are supposed to have a light film of lube on them. There shouldn't be any "tight spots" in the tunnel. If you're concerned, have it looked at by someone who knows the particular breed.

Most AR15 style rifles are pretty reliable and not nearly as jam prone as most folks would have you think.

Things to do are lube the bolt inside the carrier, make sure the gaps in the gas rings (those are at the tail end of the actual bolt) aren't lined up, lube the carrier inside the upper and try a new magazine.

You'll learn more than you want to know at AR15.com if you can get past some of the poster's age/IQ/BS...

Check to see if the ectractor spring is in upside down.

All good advice ; Some times it can be the smallest least thought of part . Like the Magazine follower !. Then as suggested some times a Magazine is just no good .

Does this fellow reload ?, if so check OAL of cartridges AR's are sensitive to that .
Pull the bolt carrier out check for wear spots properly lube and replace it . Clean the Chamber with a chamber brush while the bolt is out .

If all the above fail springs or gas rings are suspect . Have a " Qualified Person " check or redo them if neither of you are familiar with servicing AR's .

Shoot Straight Know Your Target . ...

#1 - clean and lube
#2 try another magazine

1. Clean and lube the bolt carrier
2. Try a mlitary magazine
3. Be sure to full length size the brass every time you reload
4. Be sure the OAL of the round is correct

Try the above items and eliminate any loading errors. If these don't solve the problem then we can look at some mechanical problems with the rifle.