So I've put together a unique Gauss shotgun with some meshes and textures from the community, but I'm having an odd problem. The weapon will only do damage if you use it in vats, and I'm not sure as to whats causing this or how to fix it. I've only modified the weapon and its projectile, here are some screens of the data http://img571.imageshack.us/i/help1.gif/ http://img299.imageshack.us/i/help2.gif/ http://img14.imageshack.us/i/help3b.gif/

Well, all the weapon screenshots look fine. I am guessing its something wrong with the projectile, but when I try to view that picture, my security goes off its chair and blocks the page saying I am being attack by a covenent of malware and trojans. I also notice the link is not in the same format as the other 3. Perhaps you gave the wrong link? But I bet the projectile is the issue, so if I can look at it maybe I can help.

I have no idea why you'd be getting malware viruses etc. from that link cause it worked fine for me when I checked it, but just in case I removed it and added a new one here http://img97.imageshack.us/i/help4.gif/. Also I think I've found the problem the projectile has a explosion attached to it that does zero damage and I'm guessing thats whats causing the problem.

So if the weapon's base damage is 75 and the explosion's damage is also 75 would that make it do 150 damage? I did try setting the explosion's damage to 1 and it now does a small amount of damage outside of vats but in vats it seems to do normal damage. I'm just wondering if I did the above if it would make it do more damage than its set to while in vats. The other thing I'm thinking of is would setting the weapons damage to 0 and setting the explosions damage to whatever make it do equal damage in and out of vats (if that even works at all).

Explosions don't deal damage unless the actor's Scene Root is in their explosive radius. It's located at their feet, so...
If the explosion is just intended to be a small visual effect, rather than something with a decent radius intended to catch multiple targets, then you're probably better off setting it as an impact effect.

Thanks I've got it working now, though I'd still like to know how the gauss in the mod Gauss DX has an explosion effect that does 0 damage but the gun itself does the proper damage its set to.

You can use a regular explosion set to 0 damage, and attach a script effect enchantment to deal the damage to the target.