Yes Q and A are close and fast typing makes me the "fat finger Syndrome"
yes, its PPQ and with the large mag, it looks weird. Can't seem to find anyone who has one in stock. Even Walther direct doesn't have it. My only option is to find it from someone who doesn't need it and willing to sell
I think I know what you're asking about. When I got my PPQ SC, I too wanted to use my larger PPQ 17 rd mags with it. I tried using the grip sleave that comes with the SC for its 15 rd mags, but although it fit onto the 17 rd mags, the mag itself would then not fully insert into the gun with that sleeve (only without it).
My solution was to order 2 more SC 15 rd mags with sleeves - although I could find the sleeves by themselves, they cost 2/3 the price of the mag and sleeve, so it made more sense to just get the combo. I then took one of the new sleeves, and shortened it a very small amount so that it just allowed the 17 rd mag to fully insert, being careful not to cut it too much that it didnt over-insert and damage the extractor. I decided to adjust the lower aspect of the sleeve, for a better appearance and fit, (although either top or bottom of the sleeve could be cut). I used a small sandpaper drum on a lathe, but you could also use a Dremel - I'd suggest fixing/make stationary the Dremel itself and using two hands to move the surface of the sleeve against it for better control. Take your time. Make a 1mm cut line on the sleeve to guide you. You will only need to take off slightly more than 1 mm of material, evenly around the base (or top) of the sleeve to reach the point where it will just fully insert. You can then polish the abraded end a little if you want, but you won't see it. I now have 2 stock sleeves to use on either of the 3 - 15rd SC mags I now have, or on my other standard PPQ M2 15rd mags they also fit. I only use my modified sleeve with my 17 rd mags, and marked it so I can easily identify it.
Please note the mag follower springs in the SC mags are slightly stronger than both the 17 and 15 rd PPQ M2 mags, so function/cycling could be affected with certain types of ammo if you use these in the SC. I have had few issues, especially after my SC is now fully broken in, but test your set up thoroughly - I ONLY carry my SC with the official SC mags to be safe.
Here's one place where you can the SC 15rd mag with sleeve at a good price:
https://grabagun.com/walther-magazine-ppqm2-9mm-15rd-w-ext.html
Here's a pic of the finished, adjusted sleeve with the 17 rd mag fully inserted. Note too, that there will be a very slight gap when fully inserted, to allow it to click in fully while inserting. It isn't noticable to my hand/grip at all in use.
Hope this helps!