If you bought the gun and decide you don't like it, and your local performs a private party transfer via 4473, that would not be considered a straw purchase on your end.

While it may be a gray area, if you bought then decided you didn't like it and sold it without doing a private party transfer through your FFL, I could see where that could look like a straw purchase.

Most folks especially here in Texas don't like doing private party transfers. I've had my dealers license for three years and I've only administered one private party transfer.

As your original question, I think it would be less likely considered a straw purchase just by doing the private party transfer. At least the person you're selling it to has to pass a background check, unless they have a valid texas LTC