Did you see my previous post regarding the Henning base pads? Those seem to be the way to go if you are seeking to increase capacity on the 126s and use them with an ODS grip (+3 rounds and a flush fit / mechanical stop). Or, if you are OK with stock capacity in the 126s, then the 10-8 base pads for ODS grips are GTG as well, however you would need to switch out your magwell (FYI MachineWerks makes a magwell that is identical to the STI slim-tac, but accepts all base-pads).about to order about x4 126mm 17 round mags to double my mag collection for the C2
regarding what base pads to get, it seems like the stock c2 basepad is 3mm?? I used a pair or calipers and it seems close to that, the gap between the basepad and the magwell is about 2mm, so it would seem the 3mm and 4mm are good to go?
Regarding the TTI base pads: All are GTG. With these, the base pad / magwell gap won't change no matter which one you use. The overall mag length increases as you go up in BP size, and you will not get a mechanical stop with any of them when using a 126 in an ODS grip. So, it just depends on what "+" capacity you desire vs. the overall mag length you are OK with.