The stock you show that you 'refinshed' looks okay...but truthfully it's looks like you didn't get "finished with it". It looks to be low grade very open grained Black walnut.

All wood is not created equal...Lower grades of walnut are harder to fill and can look like a cheap bowling pin when done improper.

Higher grades of Bastone, Claro and French Walnuts don't look like "plastic bowling pins" when properly finished.