My P226 shoots 115 grain ammo of any manufacture into wonderfully small groups. When it comes to 124 and 147 grain the groups are much larger. I also tried a factory threaded barrel with the same results. Like I said, it shoots the 115s like a laser beam so I shoot those in it. I just find this interesting.

I have two P226s and they are both wonderfully accurate with a wide variety of ammo including 124 and 147 gr. I typically shoot Federal American Eagle or Speer Lawman but never had a problem with accuracy from any ammo I have tried.

It might help to try shooting from a rest to evaluate accuracy with different ammmo if you have not tried that yet. A particular pistol may have better accuracy with some loads than others but usualy the difference is not that much especially at shorter ranges like 30 feet or less.

I haven’t experienced that with either of my 226’s. What distances and what brand of 124 and 147?

I have a Legion P226 and I've yet to have ANY kind of hiccup using a variety of range, weight, and hollow point rounds.

Yes. Mine loves 124 gr