Strawed Parts...
 

Curious what parts someone decided to straw...

http://www.gunbroker.com/Auction/Vie...?Item=90220701

If the main spring has also been strawed, wouldn't that change/damage the strength of the spring?

Mauser720 - Ron

Ron, I believe it was thought that strawing actually INCREASED the strength of the part. That's why the sear bar is strawed on the Borchardt pistol. It was felt at the time that this part needed added strength to withstand repeated firing.

Strawing is a controlled surface coloration (don't know the exact process, but it involves oxidation and carbon content), and unless higher temperatures are involved than those required to achieve the straw color it doesn't change tensile strength an appreciable amount.

I believe you to be correct, Ron. Maybe that's why the sear bar was blued later with Luger production.