TRT-- how to backfill insulin syringes

Hey guys been a while since I posted. Got on prescribed TRT a while back, I believe I posted about that. best fucking decision of my life. should have done it years ago. anyway I inject .5ml (50mg) of test cypionate twice weekly I've been drawing with 23g and injecting with 25 and decided that it's time to move to insulin syringes for comfort and less scar tissue.

So my question is this: do you generally fill multiple slin pins at a time? I'm trying to picture how this would work. could I fill a regular 3ml syringe and then fill 6 insulin syringes? would I just draw right to the 3ml line and ignore the slight amount in the needle? if I created an air bubble by drawing the solution in the needle it would then settle to the top which would make measuring a little more difficult since I have to flip the 3ml syringle needle side down to fill the slin pins and bubble would settle to the top.

Also I have a bunch of 29g 1/2" slins, are these suitable for delts?

thanks

I do .20 ml subq 3x a week with a 29 gauge just fine. Unless you are very low BF, it's worth a shot. When filling, I just stick the needle in there, pull it back, and prop it up upside down and wait.