C421 PLT HAD A TRACK DEV WHILE FLYING THE VOR DME-A APCH TO MSO.

Narrative

I WAS ON A VECTOR TO INTERCEPT THE FINAL APCH COURSE FOR THE VOR/DME-A APCH TO MSO. WHEN I SET UP THE HSI FOR THE APCH I INADVERTENTLY DIALED IN THE 275 DEG RADIAL (095 DEG COURSE INBOUND) INSTEAD OF THE PUBLISHED 285 DEGS (105 DEG INBOUND); AND REPEATED THE ERROR WHEN I SET UP MY #2 VOR HEAD. WHILE ON THE VECTOR; THE CTLR NOTIFIED ME THAT I 'APPEARED TO BE WELL S OF THE APCH COURSE' AND GAVE ME A L TURN TO PUT ME BACK ON COURSE. HE ALSO GAVE AN APPROX DISTANCE OFF-COURSE; BUT I DON'T' RECALL WHAT HE SAID; AND I DON'T REMEMBER THE DME DISTANCE DISPLAYED ON MY EQUIP AT THE TIME HE CALLED. IMMEDIATELY AFTER THE SECOND VECTOR I REALIZED AND CORRECTED MY SET-UP ERROR; AND INTERCEPTED THE PUBLISHED COURSE. AT THE TIME I RESPONDED TO THE CTLR'S CORRECTION; I WAS APPROX ON THE 278 DEG RADIAL (ABOUT 3 DEGS FROM CTRING ON WHAT I HAD SET UP); OR ABOUT 7 DEGS S OF THE PUBLISHED APCH COURSE. WITHOUT KNOWING THE DISTANCE OFF COURSE; HOWEVER; THERE IS NO WAY I CAN NOW CALCULATE HOW FAR I WAS FROM THE VOR -- AND AS I NOTED; I DON'T RECALL THE DME DISTANCE. THUS; ALTHOUGH THE CTLR DID NOT MENTION IT; THERE'S AT LEAST A THEORETICAL POSSIBILITY THAT I CLIPPED THE NORTHERN EDGE OF THE TFR DESCRIBED IN FDC 3/7200 (MSO 256 DEG RADIAL AT 25 NM; 5 NM RADIUS; FOR FIRE FIGHTING ACTIVITY); WHICH LIES ALONG THE SOUTHERN EDGE OF THE APCH CORRIDOR FOR MSO RWY 11. WHILE IT'S IMPORTANT TO KEEP TRACK OF TFR'S; I THINK I COULD HAVE PAINSTAKINGLY MAPPED OUT THE WHOLE AREA ON MY CHARTS AND IT WOULDN'T HAVE MADE ANY DIFFERENCE. MY ERROR WAS A SIMPLE MISTAKE IN SETTING UP MY EQUIP. ALL THE NOTAM READING AND PLOTTING IN THE WORLD WON'T FIX THAT. I THINK THE ERROR RESULTED FROM LACK OF GENUINE CURRENCY. I WAS TECHNICALLY CURRENT (JUST PASSED A 135.293/.297 RIDE THE WEEK BEFORE; AFTER AN EXTENDED PERIOD OFF FLT STATUS); BUT NOT GENUINELY COMFORTABLE. I HADN'T FLOWN THIS AIRPLANE IN NEARLY 2 MONTHS PRIOR TO THE FLT CHK. THE REST OF THE APCH WASN'T PRETTY; EITHER: SLOPPY ALT CTL; LATE LET-DOWN; MULTIPLE CONFIGN CHANGES TO 'MANAGE' DSCNT; AND A SLIGHTLY BUSTED MINIMUM AT THE FAF OWING TO POOR DSCNT CTL -- ALL OF WHICH ARE SYMPTOMS OF BEING 'BEHIND THE AIRPLANE.' THE ONLY THING I DID RIGHT WAS DECLINE A STRAIGHT-IN LNDG ON RWY 11 IN FAVOR OF A CIRCLE TO RWY 29. THE ONLY CURE FOR THIS IS TO GET BACK INTO THE AIRPLANE WITH A SAFETY PLT AND BRUSH UP. IF I'D DONE THIS A WEEK AGO; I WOULD HAVE BEEN 'AHEAD' ENOUGH TO AVOID DUMB SET-UP ERRORS; AND THERE WOULD HAVE BEEN NO EVENT TO RPT.