Now, the responses you have received up to now may be correct for your situation. But to determine that, you need to do the "tilt test" to see if your op rod is moving freely as it ought to. Here's a thread from the CMP forum that explains this issue: http://www.odcmp.org/new_forum/topic.asp?TOPIC_ID=69967&SearchTerms=tilt+test
If this test shows your op rod is not moving freely, check out this post: http://www.odcmp.org/new_forum/topic.asp?TOPIC_ID=66819&SearchTerms=jim+swartz
It has the email address of Jim Swartz, the op rod whisperer. He has the equipment, and more importantly, the know-how, to put your op rod back into spec. His fee is reasonable, and he is reliable and trustworthy. Good luck––a binding op rod is a hindrance to M1 accuracy.
Edited to add: sorry, links are not hot, but they are correct.