Model 69 ball lock ??

[fortyshooter]

Just how much is this adding to the crane lock up given the low tension on the ball spring and the apparent misalignment of the V groove??? This is a picture of my 69.

 

[Lou_the_welder]

That is normal. There are threads relating to this topic.

Sent from my SM-N950U using Tapatalk

 

[Kernel Crittenden]

It would be misaligned if it were centered in the groove.

 

[fortyshooter]

Appears to be a machining or blueprint flaw that they let slip through. Being a retired Toolmaker and knowing a few things about ball locks....the ball supposed to be centered in the groove to give 100% lock up.
I guess 50% is better than nothing nowdays.

 

[PsTaN]

Mine looks the same.

 

[kaaskop49]

When the Model 69 first appeared (was it 4 years ago?) this very matter, the ball lock not centering in the notch, was heavily debated on this forum. A search will turn up literally TONS of pages on the ball lock.

Kaaskop49
Shield #5103

 

[shocker]

One instance posted on the forum where the ball didn't touch the notch at all, that's a defect. IIRC, this design started with the X-frame revolvers so it's not a blueprint error nor machining error.
The short barrel version has a different design - moved the detent so customers can't see it. Out of sight, out of mind.

 

[scooter123]

Appears to be a machining or blueprint flaw that they let slip through. Being a retired Toolmaker and knowing a few things about ball locks....the ball supposed to be centered in the groove to give 100% lock up.
I guess 50% is better than nothing nowdays.

As a working Engineer I have to disagree with your statement, something rather typical between Toolmakers and Engineers. This is an application where the ball should NOT be centered in the notch, it should be providing a Pre-Load Force acting to keep the cylinder firmly pressed into the engagement.

Note, as has always been true the Engineer always gets what he desires and the Toolmaker reserves the right to say I Told You So for a year or two after that Engineer falls flat on his face. I will also note that I've learned a great deal from Toolmakers over the years and make it a habit to listen to their suggestions but this is a case where a Pre-Load design is superior.

 

[Dave Lively]

The link below points to a picture I took of mine for a previous thread. As others have stated this is by design and the way it is supposed to be. I don't have a 2.75 inch model but have read they "fixed" the perceived problem by covering the ball up so nobody can see it.

BTW, I do clean my guns. If anyone disagrees let me take a picture of your gun with a 1:1 macro lens and we will see just how clean they really are.

SW 69 = failure

 

[Paul105]

Here's the new lock up on the 2.75" M69

Crane/

Frame

I'll pick up my new (backup) 2.75" M69 today. Don't have a stocking dealer, so always order from Davidson's (replace/repair guarantee) when possible. Pay a bit more for the peace of mind.

Report will follow.

Paul

 

[fortyshooter]

As a working Engineer I have to disagree with your statement, something rather typical between Toolmakers and Engineers. This is an application where the ball should NOT be centered in the notch, it should be providing a Pre-Load Force acting to keep the cylinder firmly pressed into the engagement.

Note, as has always been true the Engineer always gets what he desires and the Toolmaker reserves the right to say I Told You So for a year or two after that Engineer falls flat on his face. I will also note that I've learned a great deal from Toolmakers over the years and make it a habit to listen to their suggestions but this is a case where a Pre-Load design is superior.

Well I don't know if you own a Model 69 but the light pressure under that ball isn't going to provide much locking assistance given that it's only contact point is on the ramp leading out like a roller lifter with light spring pressure.
Why would you have a notch cut in there if it wasn't for a locking purpose?
If I were to disable the rear cylinder locking pin, that cylinder would fly right open with a good shake.
Maybe they should call it a light friction lock.

Anyway appreciate your Engineering comments and thanks for the links on the ball lock issue.

BTW...during my working days in the Tooling Dept. of a large office furniture corporation we would get stamping/forming multi station dies shipped in from a contract builder.
My job was to make them FUNCTION correctly to produce the intended part.

 

[Paul105]

Picked up my second 2.75" M69 a couple of days ago. Visual inspection -- no apparent anomalies. Went to range and shot some factory and handloads. All .44 Mag -- POI was a bit more left with rear centered than should have been. Over the next several days, shot a bunch more .44 mag ammo -- both Factory and Handloads. Cyl gap at least .010 (feeler gage go at .010). Plug gages .428 go, .429 no go -- didn't slug bbl.

Chronoed loads (previously w/2.75" M69) -- Temp diff, but some faster, some slower -- none more than 40 fps diff.

Couple of groups from new 2.75" -- (yeah, rear not centered, but won't be sending back)

265gr SWGC (Thompson 429244), 17.5gr A2400 (Deep seated - over front drive band), chrono right at 1,100 fps at 80 deg f and 5 long paces fr muzzle. 25 yds rested on carpet squares.

 

[Tom S.]

Appears to be a machining or blueprint flaw that they let slip through. Being a retired Toolmaker and knowing a few things about ball locks....the ball supposed to be centered in the groove to give 100% lock up.
I guess 50% is better than nothing nowdays.

As a working Engineer I have to disagree with your statement, something rather typical between Toolmakers and Engineers. This is an application where the ball should NOT be centered in the notch, it should be providing a Pre-Load Force acting to keep the cylinder firmly pressed into the engagement.

Note, as has always been true the Engineer always gets what he desires and the Toolmaker reserves the right to say I Told You So for a year or two after that Engineer falls flat on his face. I will also note that I've learned a great deal from Toolmakers over the years and make it a habit to listen to their suggestions but this is a case where a Pre-Load design is superior.

Well I don't know if you own a Model 69 but the light pressure under that ball isn't going to provide much locking assistance given that it's only contact point is on the ramp leading out like a roller lifter with light spring pressure.
Why would you have a notch cut in there if it wasn't for a locking purpose?
If I were to disable the rear cylinder locking pin, that cylinder would fly right open with a good shake.
Maybe they should call it a light friction lock.

Anyway appreciate your Engineering comments and thanks for the links on the ball lock issue.

BTW...during my working days in the Tooling Dept. of a large office furniture corporation we would get stamping/forming multi station dies shipped in from a contract builder.
My job was to make them FUNCTION correctly to produce the intended part.

Scooter123 is right on this. If the ball lock was needed to stop movement in both directions (right and left), the proper location for the ball would be in the center of the "V". Since it is only needed to restrict movement to the left, concentrating its force on that side of the "V" serves the purpose. Regarding the amount of tension it has, remember that it is working in conjunction with three other locking/locating mechanisms, plus if it was too strong, opening the cylinder would be more difficult.

 

[dogdoc]

All I have seen including mine and my sons 69 are like that

 

[Warren Sear]

Well I don't know if you own a Model 69 but the light pressure under that ball isn't going to provide much locking assistance given that it's only contact point is on the ramp leading out like a roller lifter with light spring pressure.
Why would you have a notch cut in there if it wasn't for a locking purpose?
If I were to disable the rear cylinder locking pin, that cylinder would fly right open with a good shake.
Maybe they should call it a light friction lock.

Anyway appreciate your Engineering comments and thanks for the links on the ball lock issue...

My thoughts exactly. That spring-loaded ball does little, if anything, to add to the lock-up strength.

If the ball lock worked, you would not be able to open the cylinder.

 

[steelslaver]

All the front lock has to do is over come the slight pressure from the hand rotating the cylinder and most of that force is taken up by the ejector center pin locking into its spot in the recoil shield. The conventional old style lock has its some draw backs too. Rod must be 100% true, or a bit of changing pressure as it rotates, causes a bit of friction from riding in the end of the rod, there has to be a bit of tollerance where rod passes through yoke or more friction. So the tolerances in rod, end of rod and pressure from front locking bolt, tolerance and friction in yoke and it all adds up. Do this experiment. Take the locking bolt and spring out of the barrel lug on a couple S&W revolvers, Make 100% sure they are empty and from the front, closely op serve the yoke where it meets the frame. How much does it open up as you cycle the cylinder? How much is it open after cylinder locks up? Using a finger just how much pressure does it take to keep it completely closed up? On a gun that is functioning smoothly and correctly the yoke to frame doesn't open up, once the hand has done its job their is no side pressure on cylinder and any movement is easily stopped by a very light side pressure. Look at all the older guns that got snubbed and the front lock moved to a ball detent on the yoke. Actually pretty small ball and light spring. Lots of Bull barreled competition guns were/are made with out any front lock. Do I want a front lock on my guns? Yes. How critical is it. Not really that much

 

[fortyshooter]

Picked up my second 2.75" M69 a couple of days ago. Visual inspection -- no apparent anomalies. Went to range and shot some factory and handloads. All .44 Mag -- POI was a bit more left with rear centered than should have been. Over the next several days, shot a bunch more .44 mag ammo -- both Factory and Handloads. Cyl gap at least .010 (feeler gage go at .010). Plug gages .428 go, .429 no go -- didn't slug bbl.

Chronoed loads (previously w/2.75" M69) -- Temp diff, but some faster, some slower -- none more than 40 fps diff.

Couple of groups from new 2.75" -- (yeah, rear not centered, but won't be sending back)

265gr SWGC (Thompson 429244), 17.5gr A2400 (Deep seated - over front drive band), chrono right at 1,100 fps at 80 deg f and 5 long paces fr muzzle. 25 yds rested on carpet squares.

Notice a lot of side blast with the .010 gap? Don't know why they can't keep it in the .004-.008 range.

 

[fortyshooter]

Just took a look at my Charter Arms Bulldog .44 Special...only one cylinder lock point and that's at the rear of cylinder...ejector pin lock. Nothing locks up at the front not even at tip of ejector rod.

Now at .44 Special pressures maybe it works good enough!

 

[ken158]

Always interesting to see the flock try to out engineer the engineers...

 

[Paul105]

fortyshooter -

Make sure you get your rebate ($30 for revolvers)

Rebates | Smith & Wesson

Didn't notice any more "sideblast" than usual. Although these little guns will generate a fireball depending on the load/powder being used. My original 2.75" with a friend shooting.

24.0gr W296, 240gr JSP

23.0gr Accurate 11FS (Flash Suppressed), 240gr JFP

Looks like most is coming from muzzle.

Paul