diff --git a/python/obitools3/version.py b/python/obitools3/version.py
index 606976a..693bf2e 100755
--- a/python/obitools3/version.py
+++ b/python/obitools3/version.py
@@ -1,5 +1,5 @@
 major = 3
 minor = 0
-serial= '0-beta14a'
+serial= '0-beta14b'
 
 version ="%d.%02d.%s" % (major,minor,serial)
diff --git a/src/obidmscolumn.c b/src/obidmscolumn.c
index 9ab5ecf..ff1fc73 100644
--- a/src/obidmscolumn.c
+++ b/src/obidmscolumn.c
@@ -1974,6 +1974,10 @@ int obi_enlarge_column(OBIDMS_column_p column)
 	// Calculate the new file size
 	old_line_count = (column->header)->line_count;
 	new_line_count = ceil((double) old_line_count * (double) COLUMN_GROWTH_FACTOR);
+	if (new_line_count > old_line_count+100000)
+		new_line_count = old_line_count+100000;
+	else if (new_line_count < old_line_count+1000)
+		new_line_count = old_line_count+1000;
 
 	if (new_line_count > MAXIMUM_LINE_COUNT)
 	{
diff --git a/src/obidmscolumn.h b/src/obidmscolumn.h
index f4cadde..c571345 100755
--- a/src/obidmscolumn.h
+++ b/src/obidmscolumn.h
@@ -34,7 +34,7 @@
 #define NB_ELTS_MAX_IF_DEFAULT_NAME (1000000) 	/**< The maximum number of elements per line if the default element names
 										   	   	 *   are used ("0\01\02\0...\0n"), considering ELEMENTS_NAMES_MAX.  // TODO not up to date
 										   	   	 */
-#define COLUMN_GROWTH_FACTOR (1.3)	 	  		/**< The growth factor when a column is enlarged.
+#define COLUMN_GROWTH_FACTOR (2)	 	  		/**< The growth factor when a column is enlarged.
                                 	   	   	   	 */
 #define MAXIMUM_LINE_COUNT (1000000000)   		/**< The maximum line count for the data of a column (1E9). //TODO
                                 	       	   	 */