Found some cool gun assets on Marketplace for Shooter mega challenge

Found “Military Weapons Silver” and “Military Weapons Dark” on Unreal Marketplace by Adia Entertainment. Initially was bummed as it only supported up to Engine version 4.21. Discovered can easily migrate these over to latest (currently 4.27.1) .

Just need to additionally install the latest compatible engine version.

Go to Unreal Engine → Library and install the newest compatible engine version: 4.21.2. Then create an empty blueprint project in that version. Then add the assets to the project. You can then open the showcase level, click on the asset you want, go to browse to asset, and then right click and do “Asset actions → Migrate” and then you can choose your newer engine version project. This will import the asset tree into your project. This worked great! Hope it helps others.