problems with Normal maps

Hemin

Hello everyone
I have been trying to bake a normal map from AK 47 high res model and I can't seem to figure out why I'm getting this nasty horrible artifacts around the edges of my model after baking.
 I have smoothing groups applied to my lowres, I have tried baking the normal maps in 3dmax, topogun, xnormal,and substance painter they all seem to give me the same result I will be very grateful if anyone could point out what I'm doing wrong here. I have attached a few images to show the results which I'm getting from 4k map. 
 Many thanks in advance 

Swizzle

Do your UV seams match the edges of your smoothing groups? Artifacts like this are common around hard edges with connected UVs.

If you haven't already, you should separate all your smoothing groups into separate islands so that you get nice edge padding; this should eliminate some of the baking errors and give you cleaner results.

RaptorCWS

I think Swizzle is right. it appears that you do not have a separate uv island wherever you have a smoothing group, or you do not have enough edge padding between you uv islands.

Hemin

Thanks Xavier and Raptorcws, I have matched my smoothing groups with my UV islands this has eliminated some of the artifacts effects but still appears jagged in areas. 

Obscura

Do you use edge padding?

.Wiki

Obscura said:

Do you use edge padding?

This and try to flip the green channel of your normalmap. And make sure your uv islands are as straight as possible, this will reduce aliasing.

Hemin

yeah I'm using substance painter for baking the normal map, I I think Dilation Width in  substance painter is equal to edge padding in xnormal or  in any other 3d packages I'm using the value of 16.

.Wiki

It appears that you got no cage. This is fine with smooth meshes, but when you got hard edges you will need a cage. Otherwise the baker won´t proper catch the normals at the hard edges.

Hemin

Thanks Wiki I used a cage as well  it still appears jagged in areas