Can you use a FN 509 midsize magazine in an FN 509 tactical pistol? (I know it's 15 vs. 17 or 24 rounds, but will they work ok?)

Also, anyone know who might have some 24 rounders in stock?

Thanks!

No, the mid-size mag is too short to fit in the full-size grip.

509s are like Glocks, the smaller guns can use mags from the bigger ones but not the other way around. Like the G26 will work with 10rd G26, 15rd G19, and 17rd G17 mags but trying to put the 10rd G26 mag in the G17 is just silly.

ETA - I haven't seen the 24rd mags anywhere for a while.  509 mags have always been hard to find.  I used to just put in backorders with Brownells but they aren't taking them anymore.  Best bet is setting up in stock notifications with Brownells, Midway, FN's eStore, etc and picking up what you can.  I've painted several black baseplates to look better with the FDE.  Aervoe Field Drab is a touch "warmer" in color than FN's FDE (more of coyote brown), but it is pretty close and works FN's 50 shades of FDE manufacturing approach.  New production Alumahyde in Magpul FDE might be a closer match, I have a few cans but I haven't tried it out yet.

ETA - I painted a few more baseplates last weekend, Aervoe Field Drab was still my choice.  Since the weather was nice, I did spray some side-by-side Aervoe, old production Alumahyde Coyote Brown, and new production Alumahyde Magpul FDE.  FN's color is warmer and looks matches best with the Field Drab.  Brownells fixed their naming, so the old Coyote and new Magpul FDE are the same color.  They are that more tan/gray FDE that Magpul has long used, which is not FN FDE.

If anyone is looking, FN has them again at this moment.

Doc