Hi- Rufus started insulin in November. I am now on my second box of syringes. They are 29 gauge. 1st box no real issues except learning curve. I'm on 2nd pack of 10 in 2nd box and these syringes seem to be more resistant to pushing through, if that makes sense. It's not every syringe but maybe 5 or 6 0ut of about 15 seem harder to push through. Do you think manufacture defect? Should I maybe go for a 31 gauge? Any thoughts?