Hard To Remove Grip Frame Pivot Lock Screw

[azdover]

Just a heads up.  I've edited this post from when I originally posted it to correct some wrong assumptions I made.  I still think the general idea still might be helpful if somebody runs into a similar problem.

I'm not sure if this a common problem, but this is the first time I've run into this during my limited experience with Ruger single actions.  When trying to remove the grip frame pivot lock screw ("long grip frame screw" for short), it would back out about a quarter turn and then lock up.  I tried heating it up with a propane torch thinking it might be thread locked - still no luck.  Just as I was reaching for the trusty angle grinder, I thought I'd try one more thing.  I tightened the screw and then backed it out repeatably.  It finally started to rotate counter clockwise a bit at a time and then finally came out. Taking a close look at it, the tip of the screw that engaged the hammer pivot was severely deformed.



Compared to other few guns I have, this screw was pretty mangled although all of them were slightly deformed.  Looking at the parts involved, the long screw tip is wider than the grove in the hammer pivot which must have caused the deformation.  Maybe it was designed this way so the tip would deform to help lock the screw in place, but I wouldn't know.

To help prevent this problem in the future, I'm going to round the tip slightly so it just fits snuggly into the hammer pin groove taking care not to shorten the long screw at the same time.



CORRECTION!  THE PICTURE ABOVE SHOWS THE WRONG ORIENTATION OF THE SCREW AND HAMMER PIVOT.

The screw actually engages the pivot from behind.  An undamaged screw tip radius should match the hammer pivot grove when properly installed.  When I rounded the damaged screw tip, it allowed the hammer pivot to slide slightly side to side since the screw no longer firmly fit in the hammer pivot groove.  Hopefully, I caught this early enough so nobody followed my suggestion.  And I have already ordered a new long screw to replace the damaged on.



Side view of hammer pivot hole when long screw is installed.

I also think I know what caused the problem, which I will explain in a post below.  Of course "thinking" is part of the problem that got me into this mess to begin with.

Just something you guys might want to keep in mind next time you're trying to get that "@*!" grip frame pivot pin screw out before resorting to heavy equipment or high explosives.  Try working it out slowly - tighten and then loosen repeatedly - and it should come out eventually.  Hopefully, more knowledgeable folks will speak up in case I'm way off base here (which I frequently am).

Pete

[pleadthe2nd]

I have never seen this, good catch, and solution

[seminolewind]

Just a reminder to everyone, the hammer pin goes in with the grove on the loading gate side of the frame, and the long grip frame screw also goes in on the loading gate side. The frame is cut to accept the long screw on the loading gate side. Damage to the screw can occur if the long screw is installed on the wrong side. Been there.

[bradshaw]

Apr 7, 2024 9:02:17 GMT -5 seminolewind said:

Just a reminder to everyone, the hammer pin goes in with the grove on the loading gate side of the frame, and the long grip frame screw also goes in on the loading gate side. The frame is cut to accept the long screw on the loading gate side. Damage to the screw can occur if the long screw is installed on the wrong side. Been there.

*****

Correct.

When stripping revolver, it is a good idea to clean drilled & tapped holes. Gradou, including steel cuttings, sometimes clutters holes in a Ruger frame. Same is true for tapped holes in S&W frames which receive the side-late screws.
David Bradshaw

[azdover]

Apr 7, 2024 9:02:17 GMT -5 seminolewind said:

Just a reminder to everyone, the hammer pin goes in with the grove on the loading gate side of the frame, and the long grip frame screw also goes in on the loading gate side. The frame is cut to accept the long screw on the loading gate side. Damage to the screw can occur if the long screw is installed on the wrong side. Been there.

The long screw was installed on the load gate right side, although it easily went into the left side.

After reading seminolewind's and Mr Bradshaw's post, I went back to double check everything.  All the online parts diagrams showed the long screw is installed on the loading gate right side.  Looking at the original grip frame, I noticed that the left ear indexing out had a small relief cut in it but the right ear indexing lug didn't.   Here is a picture to show what I am seeing.  I also included a couple of other grip frames for comparison.  The center is from the Single Six problem child.  The left is from a recent NM BH which has relief cuts in both indexing lugs although it's a little hard to see.  The right is a Midway Bisley grip frame, which has no ears indexing lugs at all.



After screwing the long screw into the right side cylinder frame hole without the grip frame in place, it looks like the screw shaft is not flush within the cylinder frame ear indexing lug notch.  It sticks out a couple of hundredths of an inch.  Could this be what caused the damage in the first place?  If it had been installed on the left side, the screw probably wouldn't have made contact with that indexing lug.



And with the newer BH grip frame and the Bisley grip frame I have, it doesn't seem to matter which side you install the long screw, as long as it's on the same side as the hammer pivot grove.

It seems to me that if the long screw had be installed on the left side, corresponding to the "scalloped" grip frame indexing ear, it wouldn't have been damaged and hard to remove.  Could there have been design change somewhere along the road?  Terminal confusion is starting to set in.  A little help here - what am I missing.

Confused in the desert,
Pete

[bradshaw]

Pete.... check out Gallery section, DB Photos Vol 34-2 (XXXIV-2), to see the long grip frame screw goes to the left of the trigger----opposite loading gate.
David Bradshaw

[azdover]

Mr. Bradshaw - thanks for the info. Went back and put the correct terminology into my original post.

Bottom line - the grip frame hammer pivot pin screw (long screw) should go on the left side opposite of the load gate corresponding to the notched indexing lug and the hammer pivot pin should be installed with the groove also on the left.  This is opposite most of the parts diagrams I've found on line.  Guess not everything you find on the internet is true.  Somewhere along the line, somebody put the long screw on the wrong (right) side causing the damage.

Thanks again - time to go find something else to get confused about.
Pete

[bradshaw]

Pete.... as Tyrone (contender) says, “Never say never with Ruger.”

Bill Ruger incorporated two ALIGNMENT LUGS on the “ears” of his GRIP FRAMEs. These ears align into cuts in the rear of the FRAME. These allow the grip frame to be held to the frame by a single screw in front of the trigger guard. I used this convenience when doing trigger jobs on the original .357 Maximum prototypes. I learned this trick while tuning the letoff on Bill Ruger, Jr.’s coffee table.

“You know, you don’t have to use all five screws to test your work,” said Bill, Jr. “The front [grip frame] screw is all you need.” (I declined Bill’s invitation to fire a few rounds with just the front grip frame screw.)

Both right & left lugs on the grip frame were notched to allow passage of the long grip frame screw. As well, both holes in the frame were drilled deep enough to accept the long screw. On a gun so-made, all you had to remember was to insert the long screw as the flute in the flute in the hammer pin.

Variations, later on....
* As has been noted, there came grip frames with just one alignment lug notched for screw clearance.
* Frames have been made, in which the two holes behind the trigger drilled to unequal depths.
* Grip frame alignment lugs and corresponding cuts in frame were eliminated from production perhaps ten to more years ago.
* Long screw and hammer pin flute are normally on LEFT side of frame.
David Bradshaw

[seminolewind]

My lesson learned from this thread is, “Never say never with Ruger.”

Mr. Bradshaw photo essay clearly shows a notch cut on the left alignment lug (opposite loading gate) of his 357 Maximum, but my Instruction Manual for NM Blackhawk 357 Maximum says, “Note that the long screw (XRN-19L) should go in the grip frame hole on the gate side (Figure 4-B) of the revolver.” My 10” Maximum has the notch cut on the gate side as indicated in the Manual. However, my 7 1/2” Maximum has the notch cut on the opposite side from the 10”.

As Mr Bradshaw said, there have been variations along the way, which makes learning these fascinating revolvers a never ending process. I’m glad the OP found the cause of the damage to his screw.

[bradshaw]

seminolewind.... revolver in photo essay Vol. 34-2 is a Ruger S410N .44 Mag “Silhouette Super”----10-1/2” Super Blackhawk from earliest production (introduced 1979), and winner of the first International Revolver Championship.

Must now get ready to watch eclipse. Shall check screw arrangement on .357 Maximum later.
David Bradshaw

[azdover]

Ruger must live by the motto of “Change for change’s sake. Never make a perfect product. You’ll put yourself out of business.” I think I’ll send that to Hallmark so they can put it on a greeting card.

[handgunhuntingafield]

I have run into the smooth portion of the screw shank/tip or the pins retaining grove being a little large and causing some binding upon removal.

Your mashed end there…..is not something I have seen before.

When I replaced frames and such I generally looked these holes over well. They seem to be a spot where lots of burs get left behind in manufacturing. Generally just takes some minor clean up and a quick chase with a tap.

It’s always good to post these kinds of pics. It may help someone along the way if they run into a similar problem and help them figure it out. Good on you for taking the time to post it.

[contender]

"Ruger must live by the motto of “Change for change’s sake"

Often,, changes are the result of input from real shooters. Elmer is the one that got Bill to build the Super Blackhawk Dragoon g/f. He liked it,, and so do others. But that is but one example of changing something.

The NM lockwork vs the OM lockwork, came about to enhance safety. Idiots who failed to understand basic safety caused this change.

And they haven't changed some things,, ever. Just look at the Ruger SA mainframe grip mounting hole pattern. Because of them never changing that,, Ronnie has graced us with all kinds of great grip selections.


So,, yes,, with Ruger; "Never say Never!"

[azdover]

Apr 8, 2024 22:14:48 GMT -5 handgunhuntingafield said:

I have run into the smooth portion of the screw shank/tip or the pins retaining grove being a little large and causing some binding upon removal.

Your mashed end there…..is not something I have seen before.

When I replaced frames and such I generally looked these holes over well. They seem to be a spot where lots of burs get left behind in manufacturing. Generally just takes some minor clean up and a quick chase with a tap.

It’s always good to post these kinds of pics. It may help someone along the way if they run into a similar problem and help them figure it out. Good on you for taking the time to post it.

Even though Ruger single actions are relatively simple guns, I learn something new about them every time I take one apart or courtesy of the the much more knowledgeable folks on this forum.  I think there's a certain elegance of design when somebody does something that works with fewer parts compared to another product that uses more pieces.  Plus that means less parts to lose, especially those little tiny pins and springs.

Like I mentioned before, the long screw was installed on the right (but not the correct) side, which in this case was the indexing lug without the scallop.  That may have been what caused the problem and damage to the long screw.

What really caused a three alarm helmet fire was when I installed the long screw on the left side of the cylinder frame to check fit.  It almost didn't come out again!  Maybe the long screw tip was a little large like you mentioned.  I must have pissed off the ghost of Bill Ruger with my tongue in cheek comment about change for change's sake and he was getting even with me (I was just kidding!).  

After finally getting it out, the tip was deformed again.  I used an appropriate sized drill bit to clean out any possible burs and smooth the right cylinder frame hole, plus cleaned up the long screw tip again.  It finally screwed in and out smoothly without any problems.

Thanks for the "tips" (I'm killing myself here )

Pete

[bradshaw]

Pete.... Bill Ruger liked to make one parts serve two jobs, an engineering concept invented long before John Moses Browning or Bill Ruger put it to use.
Couple of examples on the New Model
* BASE PIN spring loads transfer bar while serving as cylinder. axle.
* LOADING GATE swings open to load/unload, simultaneously "locks" transfer bar.
* TRANSFER BAR enables hammer ro strike firing pin (when hammer is cocked and trigger is pulled). Transfer bar & loading gate form heart of the passive safety..
* LOADING GATE SPRING holds gate closed, and when open. As gate is opened, gate spring depresses bolt to allow cylinder rotation from loading/unloading. Gate spring also secures trigger pin.

Since hammer cannot be cocked while trigger is blocked, revolver cannot be fired during load/unload sequence.

With revolver at rest, hammer does not reach firing pin.Ipening the loading gates locks the lockwork. Loading & unloading are accomplished WITHOUT TOUCHING HAMMER or TRIGGER. By definition, a PASSIVE SAFETY system.
David Bradshaw