Welcome to the Forum. I see that you asked the same question on the hepatitis forum. I will make a few comments however your question really has more to do with the instruments needed for tattooing than anything else and that is something I know little about.
Certainly both hepatitis C and HIV can be transmitted when tattoos are made using unclean needles. It sounds to me as though the measures your tattoo artist took were appropriate (i.e. using new, disposable needles and not using inks which might have been contminated) and should prevent infection as I doubt that the material from persons being tattooed moves up into the tattoo gun itself but as I said, this is something I am not expert in. My guess is that your risk is low.
The fever that you had 2 days after getting your tattoo was far too soon to be due to HIV or to hepatitis C and was certainly caused by something else.
Sorry I can't be of much more help. If you choose to seek testing I would suggest waiting 6-8 weeks until you do so as earlier tests could be falsely negative. While recommendations say that it can take up to 3 months for blood tests to become positive, that is rarely the case. EWH
He was using new needles and even if HIV was on anything else including his hands not just tattoo gun grip would not survive that long outside it host. My concern in this case would be especially hepatitis C.I will wait 3 months and get tested for both just to be on safe side.
Thank you for you trying to answer my question I hoping that way that I m thinking make sense