This code is working but it is so slow for 10k records. Is there any faster way to bulk insert data into SQL Server?

This code is working. And it is better than saving records row by row, but it is so slow for 10K records. Is there any faster way to bulk insert data into SQL Server?

Adding bulk data into database

using (var scope = new TransactionScope())
{
    string connectionString = "Data Source=94.73.148.5;" +
                              "Initial Catalog=YirmibesYazilimMutabakat;" +
                              "User id=id;Password=password;";

    var sqlConnection = new SqlConnection(connectionString);
    var sqlBulkCopy = new SqlBulkCopy(sqlConnection)
    {
        DestinationTableName = "FaturaExcel",
        BulkCopyTimeout = 6000
    };

    var dataTable = copyExcel;
    sqlConnection.Open();

    sqlBulkCopy.WriteToServer(dataTable);

    scope.Complete();
    sqlBulkCopy.Close();
    sqlConnection.Close();
    sqlConnection.Dispose();
}

EDIT: Added BatchSize

bulkCopy.WriteToServer(dataTable); This statement takes 40 seconds. The others just fine. Additionally i could'nt use transaction.

 string connectionString ="Data Source=94.73.148.5;" +
                          "Initial Catalog=YirmibesYazilimMutabakat;"               
 using (SqlBulkCopy bulkCopy = new SqlBulkCopy(connectionString))
 {
   var sqlConnection = new SqlConnection(connectionString);
   bulkCopy.BatchSize = 4000;
   bulkCopy.DestinationTableName = "FaturaExcel";
   var dataTable = copyExcel;
   sqlConnection.Open();
   bulkCopy.WriteToServer(dataTable);
   bulkCopy.Close();
   sqlConnection.Close();
   sqlConnection.Dispose();
 }