Refinancing an investment property

[Campus Johnson]

My wife and I are new to real estate investing and we are presently in the process of taking out a merit loan on our investment property to buy another investment property. Long story short, the appraisal came back at $390,000, which my wife and I find very odd since the house tax assessment values the house at $446,600 and a previous independent appraisal  we had done a year ago valued the house at $475,000. The present appraisal is a drive-by done by an in-house appraiser from a local bank. We believe this appraisal is incorrect. Any advice?