Nice Chrome effect on the gun, you should try that on the helmet just not as shiny. This looks really good, but take your time with the pattern, draw it out first or go to http://www.dragon-miniatures.com RagingBull n this site. He has great tips for painting.
well i took a look at your orks,and im impressed this is my favourite one, love the nmm and your only 13 years old,cool really cool.(by the way thanks for the comment.).