I have no problem pinning my quads or my delts. I won't pin glutes anymore because of some bad experiences with pain and big knots on my upper ass cheek from pinning. I use 23 gauge 1 inch for delts and quads. Sometimes try different approach to pinning (ie..if you plunged fast through skin last time..try slow steady pressure turning syringe back and forth, it goes in on its own. If you did slow, you maybe try quick). I also recommend if you have a 1 inch syringe tip, you definitely need to get that tip all the way in the muscle when you shoot. You said you only got about half way in above. That can lead to more discomfort if you're not getting the pinning deep enough. I would recommend watching youtube videos on pinning. They made me feel a lot more comfortable about pinning myself, but I still won't pin my ass. Good luck man, hope some of this helps you out bro.