Unarmed Movement Speeds
To find the unarmed Movement Speeds setting open the BP_SGKContoller then select the BP_PlayerInventory component in the Components panel, then in the Details panel search bar search for Movement Speeds and you will see the settings like below.
Here you can set the movement speeds for each character state.
Holdable Movement Speeds
If you want to change the characters movement speed while holding a holdable item, then go to that items holdable blueprint like for example the BP_M4A4, then open the Class Defaults and in the Details panel search for Movement Speeds to find the settings shown below.
Use Holdable Movement Speeds – If true the Movement Speeds values set in the holdable bp will be used instead of the Movement Speeds values set in the Player Inventory, this can be used to set different speeds for different held items.
Movement Animations
After changing your movement speeds you may also need to adjust the movement blend spaces, these are used to determine what animation the character should play at what speed. You can find the blend space animations in the SurvivalGameKitV2/Animations/BlendSpaces folder.
So for example if you changed the Combat Jogging speed of the BP_M4A4 to 500 you would also need to adjust the animations in the BS_Jog_Aim_Rifle as thats the blend space used in the BP_M4A4AnimLayers in its Third Person Combat Anims setting.
Below is an example of how you can change the speed that an animation will play in a blend space.
If you want to know more about Blend Spaces linked below is epics documentation on them.
Defuse Studios 