When do you blue/brown a barrel?

[Rolf]

I just finished mounting the sights on a pistol I'm building. I cold chizeled the  dovetails for the sights and rust blued the barrel before mounting the sights. I hammerd the dovetail lip down on the sight using a brass punch. The barrel finish got a bit mared.

Do you brown/blue the barrel before mounting the rear sight or after?

Best regards
Rolf

[Acer Saccharum]

I brown after all metal work is done. After the sights have been installed.

on a rifle, when you might want to tap the sight back and forth, brown without the sight in place. If you need to clean the dovetail to get the sight to fit again, it's OK, because the sight base is large enough to cover the entire dovetail.

[satwel]

I do the same as Acer. I brown the barrel with the rear sight installed and the dovetail for the front sight cut.

[B.Habermehl]

I cut and fit both dovetails first, then brown/blue barrel. Then reinstall sights during final assembly. Make sure during the original fitting that there is a extremely small clearance under the front and rear of the front sight blade. This prevents any marring of the finish on the barrel. Simply tap the front and rear of the sight blade and close the gap. It should have been .005 or less to begin with. BJH