Just checking yote traps before the season, I’ve noticed on my #3, 4 coiled Bridgers that after a few catches the pan bottoms without firing and needs adjustment. I normally have about 1/3 of the dog in the notch. Could the base plate be bending or flexing causing this issue or should I change my adjustment technique? I don't have this issue with 2 coiled traps.

If it is only happening on the 4 coiled ones I'd say your base plate is flexing. I put new #3 music wire springs and four coiled six number 2 Bridgers and noticed the base plate was bowing upward after a season using them. Same as you didn't notice till the following season trap prep. It didn't cause them not to fire tho.

I file all but 1/32” off the top of the notch, close the dog eye to minimize movement square the end and file a 45* on the bottom. This gives me very little movement of the pan. Bend the cross base to level the pan adjust pan tention with pan bolt. I use J.C. Conner’s Taos lightening 4coil kits so not full power springs on the 4x side. Haven’t seen any bending of the frame, main frame is base plated of course. Hope this helps.

Have you changed the pan bolt, or are the original bolt? If I recall Bridgers use a bolt a shade small for the hole. When I was modifying, I always removed the factory bolt and re-drilled hole to accept a 3/16" bolt. Seems like the original bolt, would be okay for a while but with the hole being stamped out, when the would wear into place they were not firing as designed.
I would swap out bolt and readjust.
If you want that night latch, I have been using a hacksaw to create the notch on the end of the dog. And cleanup with a file.
This way they are all the same.

I'm running 4 dozen 4 coiled #3 Bridger's. Haven't had any problem with bending the baseplate or out of adjustment at all. I use dogless however, wouldn't think that would make any difference. Really like these traps.

Thanks for the input, there doesn't seem to be a lot of play or lost motion in the pan bolt, when I put a straight edge on the base plate, I can see a little light but probably from normal forming at the factory and doubtful its creating the affect. I tightened up the dog eye (cmfc) and that seemed to solve the issue, from a confidence level I need to overcome- why was it ok last year?

"after a few catches"
"why was it ok last year?"

Because the cross frame got bent inward or upward.

There is definitely a lot of flex in these traps. I had one on a drag and the coyote popped the jaws out when he hit the end. Had to use C clamps and a vice to get back in. Jaws still don’t line up perfectly after I fixed it. I’ll see if I can find the pics I took

Cross frame is bending up at the spring pin, from the pin out.

I run four coiled bridger #3 for beaver...I have them all base plated with PAWSI pans. Never had that problem but beaver probably don’t test a trap like coyotes.

I have had this exact issue with my Bridger #3s that I four coiled. But I dont think it has anything to do with the springs. I noticed that how I cut the night latch is what goofed it up. The thickness of the metal changed when I ground out the night latch and causes a dip in the pan because the dog and the latch are now making contact at a different angle then they were manufactured at because changing thickness of the metal causes something the touches even to now touch at an angle. I just simply went the frame where the dog attaches outward and it levels them back out. If you have an unmodified trap, set it, check if its level, then cut the night latch and see what happens. That's how I found out what caused mine to do the same.