hello all i,m new to the forum. got my new Q5 and i have to say its the best 9mm i have ever owned. recently i added a vortex venom red dot and she is now shooting low at 25 yards, ran out of adjustment. anyone recommend a shim brand and height to help correct poa. also has anybody changed the front sight to co witness. i have also already added an apex flat trigger to make a great trigger even better. thanks in advance for any help.