VSR-10 Inner barrel size, to outer barrel size HELP!
 

I want the cosmetics of the VSR-10 Laylax 700MM Intergral Silencer Outer Barrel, and i am getting a TightBore (6.03mm)... Which inner barrel should i get, there is a 440 a 550 or somthing like that. I heard that the 440 is to use the inigrated silecer and the 550 is if you dont wanna use it. any opinions would be great.

Also if anyone knows of any upgrade parts i should get, please feel free to list them. I currently have the 150 spring and the ZERO trigger kit with the re-enforced sear kit, it shoots nice and hard, and is pretty accurate. I want it to shoot a little further, it would also help if i stoped using such crappy ammo....

One last thing, has anyone ever purchased anything from
DEN Trinity Shop? They want paypal, but dont have an automated cart. They are located in hong kong so the shipping is alot, but then again the prices are cheap... here is a link to the VSR-10 Upgrades page!

VSR-10 Upgrades

Thanks for everyones help!