When I buy a weapons modification, how do I implement that mod? I've been carrying a longer barrel for my 357, but my gun looks the same as it always did. Is there something I should be doing to make the mod happen? If it's implemented automatically, why does it continue to show up in my inventory?

Pust RB or LB, i cant remember what one, on the weapon and then select the mod you want

We need a note on the user about what platform they are on. For PC, select the weapon, hit X, select the mod from the menu that pops up. The proper key should be on the right side of the screen when you equip a weapon. It will show as modded by being listed with a + after the name.

Thanks for the reply. I had not tried that so let me give that a try.