25G x 5/8th is all I've ever needed for any AAS injection in any site. 1" and above are generally for fat people unless your really trying to get deep into a muscle like quads
i used 1.5inch 23g guage for years. then i found 29gx1/2inch and havent looked back. only problem with these pins is volume. they are only 1ml
29 x1/2 slin pins
Which muscle groups do you focus on with slin pins? Dunno how long you can rotate shoulders and maybe quads if lean.slin pin is the way to go....I just started using em and it has made my life so much easier.
I had seen a lot of guys using slin pins and just thought it would never work/would take forever to actually get the oil in the muscle,but not so.
if you haven't tried it...you should.
as far as volume(only 1ml)it doesn't matter too much for me...I can go in the same muscle twice a week(probably more)with no problems.