Just a FYI. Purchased 1/2 doz Duke 550s at the PA State Convention this summer. Have heard the pan tension on these were a little heavy. Since I trap in an area that has both Coyotes and foxes I wanted the pan tension between 2-3 lbs. I have MB550s that I always took for granted had a pan tension from the factory between 2.5 - 3.5 pounds but since I was adjusting the Dukes thought I check the MBs. Several tested between 4-5 pounds and needed adjusted down. Could they had been lighter when new? Maybe. But if your running MB550s and are concerned about pan tension you might want to check them.

I find those type traps to be all over the place. I just check each one and reset where needed.

Not sure about the MB's, but I just got 2 dozen duke 550s this summer, all I had to do was clean up the bur under then pan and on the dog notch and every single one was between 2.5-3lbs

The MB 550's I have were all a little different worked on the dog of each until they were where I wanted them.

All traps can vary pan tension from time to time. The condition of the contact surfaces of the trap especially if they are a little rusty can increase pan tension. No different that wax traps have lighter tension than unwaxed traps.

My mb550's were all over the place with pan tension. No big deal just adjusted one by one. On the other hand my 450's were all within a half pound of each other

My MB550’s were all between 2.5-3#. My 450’s were 3.5-4#.

I bend every dog 3 degrees with a B2B bender to get solid 2.5 pounds measured the center of the pan for MB550 os 4 coils. Same with 450s , I set those for 1.5 for all species coyotes included. I also squeeze the dog eye to take the slop out and deburr the dog to get consistent engagement.

{JesseA} That's the reason so many people have the different pan tensions. Some mb-550 have that little burr some do not. The pan and the night latch may need a few strokes of the file. You may not see the little burr but take a fine pick and run it on the trigger and under the pan to check. You may be surprised haw many need attention.

The older versions of the mb 550s had stronger springs and two coils required bending the dog to get to 2.5 lbs. The newer two coils I have been getting are 2.5 out of the box.

I thought that was the big push for the 550's when MB came out with them, that they were ready to go right out of the box, and all the traps were tested for the right poundage 2.5-3.0 lbs. guess I'm going to have to check mine.

“People” are involved with making traps. Sadly people are not perfect.

Very rarely or if ever are traps ready to go right out of the box.