new pNoReloadTimer[MAX_PLAYERS] = {-1, ...};

public OnPlayerDisconnect(playerid)
{
    if (pNoReloadTimer[playerid] != -1)
    {
        KillTimer(pNoReloadTimer[playerid]);
        pNoReloadTimer[playerid] = -1;
    }
    return 1;
}

CMD:noreload(playerid, params[])
{
    if (IsPlayerConnected(playerid))
    {
        if (PlayerInfo[playerid][pAdmin] >= 3)
        {
            if (pNoReloadTimer[playerid] != -1) SendClientMessage(playerid, COLOR_FAILED, "No reload mode already enabled!");
            else
            {
                pNoReloadTimer[playerid] = SetTimerEx("NoReload", 250, 1, "d", playerid);
                SendClientMessage(playerid, COLOR_SUCCESS, "No reload mode has been enabled!");
            }
        }
        else SendClientMessage(playerid, COLOR_CORRECTION, "You are not authorized to use this command !");
    }
}

forward NoReload(playerid);

public NoReload(playerid)
{
    GivePlayerWeapon(playerid, GetPlayerWeapon(playerid), 10);
}