#include <sourcemod>
#include <sdktools>

public Action:OnPlayerRunCmd(client, &buttons,  &impulse, float vel[3], float angles[3], int& weapon)
{
    decl String:classname[64];
    GetClientWeapon(client, classname, sizeof(classname));
    if(StrEqual(classname, "weapon_rifle_m60"))
    {
        if (buttons & IN_ATTACK)
        {
            SetEntityMoveType(client, MOVETYPE_NONE)
        }
        else if (!(buttons & IN_USE))
        {
            SetEntityMoveType(client, MOVETYPE_ISOMETRIC)
        }
    }
}