If you upload the texture, we might be able to tell you if you're doing everything correct on the technical side. As reverendK said, UV layout is key for these items.
good to hear that it is launched. I remember a thread with interface layouts. Was wondering at that time if it will be done one day. I guess i'll check out that reactor tut ;)
Some beginning stages UE4 shots from my latest project, as it's based on a real world location I'm going to be utilising Google Maps to help with the layout.
The problem is that there's no one answer for everyone. For example - some will swear by UV Layout, and others will like Roadkill, and others will say that the built in UV tools are best with ScriptXYZ installed.
Your website is very clear, no problems at all with the layout. My only crit is the diffuse texture of your ak47..it looks like you have rushed it a bit.
further layout with modular pieces. Getting the proportions together. I'll be taking it into UDK eventually so I'm trying to keep everything to powers of 2 and an 8X8 grid.