Indexing of Screws

[Jack Cronkhite]

I have wondered if all screws, inside and out, were either 180 degrees or 90 degrees to the long or vertical axis of the gun when it was assembled at the factory. The obvious ones on the frame and floor plate are supposed to be like that. I have seen fore end iron with all screws at 180 but I have seen many at various angles. Were the two butt plate screws all at 180 to the vertical axis?

While hardly critical to function, it is aesthetically pleasing when all visible screws are at the 180 or 90. Was that how it was supposed to be ?? Did it matter for the non-visible screws or was Mr. P not that obsessive??

Slow night here.

Cheers,
Jack

[Jim Williams]

Yes, as near as I can tell they were that strict in attention to detail, but rightly so for any fine double. Even the Trojans had all-qualified screws throughout, including the unseen ones. They do seem to find a way to migrate over the years, most of them probably "helped" along by an unqualified "smith". The one under the top lever, though, has a habit of backing out a little on its own on many guns I've seen. I have a couple that need a little tweak every now and then if I shoot them much. A very judicious "light" application of Loc-Tite has worked fine on the ones of these I've tried it on, and they can still be removed later easily without damage.

One of the biggest reasons for the screws to not be qualified is when they aren't put back in the right hole after a disassembly.

Jim

[Dean Romig]

My experience on screw alignment has been the same as Jim's. When a screw is overtightened it not only bespeaks a careless heavy hand lacking in attention to detail but can have an adverse effect on the operation of the gun. An example of this would be overtightening the trigger plate tang screw causing malfunctioning of the triggers.

[Jerry Andrews]

Overtightening of screws has caused many a Hunter One Trigger to go haywire as well! Of course that trigger is more sensitive than most, it's about as sensitive as a 14 year old girl, and I'm quailified to say that with three daughters ages 23, 24 and 26. I've been there, I've lived it and I have stories. Jerry

[Austin W Hogan]

My own experience with the five Parkers that I have used regularly at trap skeet and five stand for the last ten years is about one turn per thousand shots. This varies by plus or minus a half turn among the individual guns but is a good rule of thumb.
Be a little lenient with exposed hammer guns. Minute changes in the stock and fore end wood can (apparently?) cause thirty degree changes in the top tang or fore end latch screws.
I have had two apparently perfect hammer screws loose heads due to metal fatigue. I am looking for a supplier of unbrako screws to use modern 4 40 screws when shooting them.

Best, Austin

[Jack Cronkhite]

Thanks everybody. Is there any fix for the heavy handed over-torqued screws?

[Dean Romig]

Is there any fix for the heavy handed over-torqued screws?

Ummm.... break his fingers? :shock:

[Jack Cronkhite]

:rolleyes: okay, coffee wiped off the screen. That was a chuckle. But, seriously..........
Cheers,
Jack

[Dean Romig]

I would imagine it could be done with a very light application of spray weld on the underside of the screw heads and then refit them.

[Eric Eis]

Try a little Teflon tape, takes a little time to figure out how much but it works.

[Austin W Hogan]

Indexed screws are a quality control technique in many precision industries. Indexed screws indicate a job is complete; unindexed screws are the sign of trial fittings and work in progress. Indexed screws were the mark of anything installed by the Flight Test Instrumentation Department when I worked in that department at Grumman.
I later worked with a superior instrument maker, Bill Winter, who indexed every screw and fitted every surface with airtight quality. The man he learned from, George Gardner, chief of the GE General Engineering Lab instrument shop fitted things as precisely but applied a unique test. After calibrating an instrument, he removed all the nuts bolts and screws, then replaced them with parts from the salvage box. If the instrument repeated the calibration he approved its delivery.

Best, Austin

[Dean Romig]

:shock:

Now that's precision!