Tricep injection help!!

[hayesjones]

I just started shooting into my triceps about 4 months ago and never had a problem, but now it seems whether its deca, fina or whatever, the plunger locks and wont inject any go go juice into my tricep.
Im using a 23g 1".
Is it scar tissue thats holding me up?

thanks

 

[PopiChulo]

I would have went with a 25g 5/8in pin less scar tissue and easier on the small muscle groups