You can get what's called a nipple pick to ensure that your breech plug is clear after each shot.
Don't dispair on the Rem 700. They have their quirks just like every ML but they are deadly accurate. I have one of the early Rem 700's.
I have not shot the 209 conversion, so I cannot tell you how thatworks.
I shoot the #11 cap with RWS caps and .44 240gr Hornady XTP/Green sabot under 90 gr FFG 777. Several other folks with the R700ML shoot that same load with very accurate results.
I clean inbetween each and every shot in every ML I own.
Try swabbing the bore after each shot with a damp (not wet) patch of 50/50 Mix of 99% Alcohol & Windex. Short stroke the patch down and up, flip and do again followed by a dry patch. Then the bore will be clean and dry. The two most successful elements to happy sabot loading. If you are a clean bore POI type like me, then you are set. Otherwise then you will need to occassionally clean the bore when loading becomes miserable.
An interesting couple of threads regarding the Rem 700.You can find more if you do a search:
http://www.huntingnet.com/forum/tm.aspx?m=1546849&mpage=1&key=cleaning& ;#1548426
http://www.huntingnet.com/forum/tm.aspx?m=2373783&mpage=1&key=&#237663 4
Hang in there with the Rem700ML. It's a good ML. Be sure to detail clean and lube the ML (including the bolt and firing pin/spring assembly) immediately after each shooting session. Folks have forgotten about the firing pin assembly only to find it rusting up to the point of not functioning.
Granted it does have it's issues, but I don't own an ML that does not. Good Luck!
Tahquamenon