diff --git a/pipekit/jrunner.py b/pipekit/jrunner.py
index 5162eae..d73f9e8 100644
--- a/pipekit/jrunner.py
+++ b/pipekit/jrunner.py
@@ -171,6 +171,11 @@ def migrate(
             argv.append("-t")
         if clear:
             argv.append("-c")
+        # SQL Server dest: stream via TDS bulk copy instead of INSERT...VALUES
+        # round trips (much faster on wide/large tables). jrunner -b is a no-op
+        # for non-SQL-Server dests, but only pass it where it applies.
+        if (dest_conn.get("jdbc_url") or "").lower().startswith("jdbc:sqlserver:"):
+            argv.append("-b")
 
         proc = subprocess.Popen(argv, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                                 text=True, env=_subprocess_env())