Damien, It appears to be prohibited. CT does not differentiate between rimfire and center fire handguns-------The following are prohibited: Semi-automatic handguns with a detachable magazine and one or more of the following features: 1. Magazine that attaches to the firearm outside the pistol grip 2. Barrel shroud 3. Manufactured weight of 50 oz or more 4. Threaded barrel 5. Magazine capacity exceeding 10 rounds No Walther PPQ M2 Handguns (Only M1). So it looks like magazine outside of grip is enough to ban this firearm in CT.

Damien, no Sir, this is not CT compliant. Details under handguns here : budsgunshop.com/feeds/state_reg/connecticut_restrictions.pdf