Just had a similar problem with an early "non easy open" frame and an octagon 25-35 barrel. I could put that barrel on my "easy open frame ", no problem. I then put my 357 Max barrel on the older frame and perfect fit, no wobble and good lock up every time!
Well then I took the "old" frame completely apart and cleaned it, readjusted the trigger and low and behold no more wobble and solid lockup every time. All this was at home without ammo to really test it. No 25-35 ammo out there, gonna have to go to the loading bench and make some up.