My texture is bunching up at the edges Its probably a subsurf issue but its preventing me texturing
So far Ive tried:
Removed doubles
Checked normals
Applied transformations
Subdivide UVs setting in Subsurf modifier
Smart UV
Its a standard uv unwrap with an edge on the back side. The cylinder is subsurfed and Im using loopcuts to sharpen edges. If I change the subsurf mode to normal it stretches the texture but creates distortions in the mesh.
Any help would be greatly appreciated 
Difficult to tell given we know nothing about your model or how you uv unwrapped it.
When you unwrapped did you enable the ‘Use Subsurf Modifier’ in the unwrap options to take into account the change in vertex position due to the modifier
Ive tried all of the unwrapping options. Not sure where the "Use Subsurf Modifier’ option is…cant see it anywhere.
The model is a cylinder that has a subsurf modifier. To sharpen certain areas Ive put loopcuts close to each other. The area Ive unwrapped is a ring of faces with a seem marked at the back. Here’s the wireframe with the unwrapped area selected and the cycles preview
Hit U to unwrap. Then you will see the unwrap options either in the “T” panel (green) or in the floating F6 tool options (red). This applies to all tools’ options, btw.
Thanks for that…didnt change anything though but I’ve learned something 
Add 4 or 5 loops on knurled part, select it ( hit L with one selected face {or vertex if you’re on latest blender}) and unwrap again, check Use Subsurf this time.
It’s not quite visible here; have you marked end rings as a seams? mark them if you have not and use plain Unwrap, no need for Smart or something.