I am about to make a observation, I took my 229 to the range and tried the 226 15 rd mags, I made a small mod on them, I used a bicycle inner tube and made small rings around the base which stopped the rattling, and secured the mag. I fired using the 2291 mags then switched to the 226 just for dodos and grins, well guess what campers , they functioned fine no jams, no problems. I don't believe will carry them but for range they worked fine. I also tried the 2291 mags in my 228 no go. also the 13rd 228 stock mags worked in the 229. I am far from a expert gun repair guy just thought I'd share this.

Many of us have used P226 .40 mags in the P229 .40. Rattle a little, but function perfectly with no mods.

I could've take the rattle, lol