View Full Version : adjusting timing on a Pietta 51?

January 4, 2009, 01:42 PM
Hey guys. How do you adjust the timing on a Pietta 51? My bolt is hitting on the leading edge of the cylinder notches, causing a burr to form inside the notch.

January 4, 2009, 03:02 PM
Well that's where it's supposed to hit. Might tweak the bolt leg of the bolt/trigger spring a bit so it doesn't hit so hard.

January 4, 2009, 04:28 PM
You can file a very slight (notice the important word, VERY) bevel on the trailing edge of the bolt. This needs to be done very carefully so that it's not overdone. After you've verified the bevel is right you need to surface harden the bolt with Kasenit and then cold blue it.

January 5, 2009, 01:03 AM
This article (http://www.theopenrange.net/articles/Tuning_the_Pietta_Part_One.pdf) should help you out.

January 5, 2009, 08:23 AM
Interesting article. Kind of jumps around a bit, and he does illustrate the problem being discussed. Unfortunately, while he covers what he's going to do, this article doesn't show the actual fix - it refers to the next month's article for that.

It is helpful, however - take a look at Photo 17 - that shows the area where the bevel needs to be filed.

January 5, 2009, 09:37 AM
You don't happen to have the second part of that article do you? Interesting reading.

January 5, 2009, 04:22 PM
I found it. :)

Part Two: Fixing The Problem Areas


January 5, 2009, 08:00 PM
He describes the bolt modification but there's no picture; it's implied in Photo 10 but you can't really see the bevel well enough. Nonetheless, a very good couple of articles that belong in anyone's archives.