I've recently been replaying Sniper Elite 5, and it's reminded me how much I enjoy building virtual weapons. Ghost Recon Future Soldier also nailed it over a decade ago, as you select barrels, triggers, stocks, and scopes that change your firearm's stats - and nothing quite beats it. It's one thing to add attachments, but physically building what you'll use in the field piece-by-piece, and surviving by the skin of your teeth because of it, is quite the payoff. While it might not have the violence, Gunsmith Simulator is finally out in Steam 1.0, and it's filled with plenty of weapons to accessorize.
Build iconic FPS weapons in Gunsmith Simulator, as it finally hits Steam 1.0
Source: PCGamesN (opens in a new tab)