Troubleshoot Tuesday!

[1911Tuner]

Troubleshoot Tuesday!

Here are the issues.

Norinco with freshly refitted slide/frame. Occassional failure to lock slide on several good, 7-round magazines that have proved dead reliable in other Norincos and Colts. Intermittent problem that could occur with any one of 36 magazines...or not. Followup check didn't reproduce the malfunction. (No...This isn't kartracer's Nork. It belongs to Kelie's ex.)

The problem:

The follower shelf climbs on top of the slidestop lug, failing to lock the slide on empty and sticking the magazine in the well until we'd pop the stop to free up the shelf.

The problem doesn't recur when hand-cycled. The problem doesn't recur
on the same magazine when retested three times.

Installing the slidestop into the frame and inserting a magazine revealed the problem, which was partly due to the slidestop pinhole being a little past at the high end of spec on the rearward location
when compared to several Colts and other Norincos...and partly due to the magazine follower shelf geometry...which causes a problem only in this pistol. In other words...a tolerance stack issue.

The magazines are Metalform. The slidestop is a USGI takeoff...likely Ithaca.

Identifying the problem took 15 minutes. The cure took less than two.

Tic-tock...

[Hersh]

Uhhh ... OK I only had to read that three times to get it , sort of :confused:

You're good Johnny .... you're very, very good.

Humble student bows and returns to meditation :D

[auto45]

Hmmm,

Refitted slide might be a bit lower than before, slide stop hole a little too rearward and doesn't happen all the time.

I'll guess the slide stop notch wasn't 'fitting' in the slide on lock up all the time even though the mag shelf was trying to push it up.

You modified the slide stop notch a bit so it engaged the slide cutout better.

[OD*]

Today's Wednesday ain't it? ;)

[OD*]

Sounds reasonable to me, auto45.

[auto45]

Ha, it is Wednesday. :)

I tried it on my gun so I don't think what I said would the problem, didn't sound bad though. ;)

Perhaps the plunger tube pin and the slide stop "stick" on occasion.

[1911Tuner]

Yeah, it's Wednesday...but I wrote this up yesterday and forgot to update the day. Technically, it happened on a Tuesday..so I guess that gets me out of it. :D


Auto45...Nope. The slide came straight down. Didn't shift to the rear. ;)

Didn't do anything to the slide.

Clew:

It's the little things that getcha...

[Hawkmoon]

You put in a different slide stop?

[1911Tuner]

You put in a different slide stop?

Nope. The fix took about 2 minutes. I can install a slidestop like...
thisquick! :D

Clew 2:

No parts were changed.

[BGregory]

Reduced the pressing of the slide top plunger on the stop itself by either stoning the face of the stop or changing the spring in the plunger.

[1911Tuner]

Reduced the pressing of the slide top plunger on the stop itself by either stoning the face of the stop or changing the spring in the plunger.

Nope. This is a weird one. Only seen it one other time...on a Remington Rand, of all things.

Clew 3:

The mag follower shelf itself can cause the same thing if it's located too far starboard, or is too narrow from the split to the port side...but not this time.
There were three issues in all. Two primary and one secondary cause.
One was with the mag follower...the other two were with the frame specs.

[1911Tuner]

Since I posted it on THR...I'll be fair and post it here too. (Cut/Paste)

I'll go ahead and describe the third one, just to be fair. Note that the problem would likely have occurred even without this one...but it was a contributor.

The bridge across the slidestop cut was a trifle small in the radius. The slidestop lug was being pressed tightly against it whenever it was pushed up by the follower shelf. This aggravated the problem, and probably caused it to occur more frequently...but it wasn't the main cause. The clue on that one was the stop falling just a little short of full engagement. When I opened it up a bit..maybe .010 inch, it was removed from the picture...but the other problem was still there.

[3jaw]

Was the mag well location correct? In other words, was it offset to the starboard side?

[1911Tuner]

Was the mag well location correct? In other words, was it offset to the starboard side?

Nope. The problem was between the mag follower...The slidestop pin hole location...and the small effect of the frame bridge radius.

[John]

Bend the follower.

[1911Tuner]

Bend the follower.

ALL-most there, Commandante! Only one problem...I'd have to bend the follower in two places, and the shelf would probably snap off before I could get it where I needed it. As noted...The follower geometry is part of the problem. Testing a follower that was formed perfectly to spec, it alleviated the problem a little, but didn't completely eliminate it.

Lemme give one more critical clew...

The shelf is bent into an "L" shape, with the vertical piece at nearly 90 degrees from the top, and the horizontal part at 90 degrees to the vertical.
This follower's vertical "leg" was formed at a little shallower angle...which puts it a bit out of spec, but doesn't cause as problem as long as the slidestop pin location is mid-spec. (The problem doesn't occur on any other pistol here...just the one.) The two issues stacked up to create a badly out-of spec condition that doesn't cause the malfunction every time on any given magazine...and not even very often. Maybe one time in 50. Since Kelie's ex goes to the range with me almost every week, I started marking the magazines whenever it would happen...and trying to correct the problem on each. I started noticing that the ones that were marked would do fine for several cycles, and then WHAM...it would happen. It prompted me to really go over it with a fine-toothed comb. When I used a strong light, I finally saw the glitch.

[John]

Wait a minute, I need some clarification here. Was the slide stop hole offset towards the rear of the frame or towards the front?

Why didn't you just spread the follower's lever towards the left a little?

[1911Tuner]

Wait a minute, I need some clarification here. Was the slide stop hole offset towards the rear of the frame or towards the front?

Why didn't you just spread the follower's lever towards the left a little?

Toward the rear. Refer to the opening post.

Tried wedging the shelf to the left a little...as is my usual fix for this particular burp. It didn't work consistently, as the ones that were marked for repair and adjusted would still do it occasionally.

So...Technically, this malfunction took only a few minutes to diagnose and fix.
In actual terms, it took several months... :rolleyes: :D

It's the little things that getcha, bossman...

[1911Tuner]

John...Since you're all over this one, I'm gonna go ahead and name you as the victor and tell the rest of the story. You're as close as you're gonna get without actually bein' able to see it. Kudos!

The pistol belongs to Kelie's ex-husband. (Long, interesting story.)

The shelf is bent into an "L" shape, with the vertical piece at nearly 90 degrees from the top, and the horizontal part at 90 degrees to the vertical.
This follower's vertical "leg" was formed at a little shallower angle...which puts it a bit out of spec, but doesn't cause as problem as long as the slidestop pin location is mid-spec. (The problem doesn't occur on any other pistol here...just the one.) The two issues stacked up to create a badly out-of spec condition that doesn't cause the malfunction every time on any given magazine...and not even very often. Maybe one time in 50. Since Tim goes to the range with me almost every week, I started marking the magazines whenever it would happen...and trying to correct the problem on each. I started noticing that the ones that were marked would do fine for several cycles, and then WHAM...it would happen. It prompted me to really go over it with a fine-toothed comb. When I used a strong light, I finally saw the glitch.

The bend formed a larger radius in the bend than should be there. As the shelf lifted the stop, the radius contacted the bottom rear corner of the lug
and actually pushed it to the right a short distance, so that just a small part of the edge of the shelf was in contact with the lug. Not often...but once in a while...the conditions were just right (or just wrong) and the shelf would climb the lug.

The cure? I cut a small bevel on the offending corner. The clearance gained
kept the radiused corner in the shelf off the lug. The follower doesn't do a sidestep..and everything was hunky-dory.

Yes. I tried other magazines to see if the ones with followers bent closer to 90 degrees would correct the problem. A few did...but most would nudge the lug just enough to move the follower over. Less than the ones involved in the malfunction...but a few still moved it. So...The cure was to modify the lug.

[John]

So what was happening was that the rear end of the ledge of the slide stop was touching the vertical part of the follower's shelf, which in turn moved to the right, allowing the slide stop to go undeneath the follower! Good Lord!

[1911Tuner]

So what was happening was that the rear end of the ledge of the slide stop was touching the vertical part of the follower's shelf, which in turn moved to the right, allowing the slide stop to go undeneath the follower! Good Lord!

It was actually contacting juuuuuuust in the bend...in the lower part of it...in the radiused area. Adding to the problem was the contact causing the slidestop to shift left to the limit
of its clearance. Not enough to cause a problem every time...but enough for me to deem it as unreliable and get my thinkin' cap on.

The total movement in follower and stop was...MAYBE..a 64th inch. (.015)
Slide to frame impact was probably the factor that brought it all together,
and provided my final "clew." When the gun was gripped super-tight...the shelf would climb the follower more often. So, we have an instance where "Limp-Wristing" actually made the gun more reliable.

Just when ya think you've seen everything... :rolleyes:

[garrettwc]

OK, tell me where I went wrong.

My theory when I read this last night (through sleep deprived eyes) would have made the problem worse. I was thinking the slide stop wasn't protruding into the frame far enough to the right and the follower was skipping over the end of it.

If I read you right, it was too far to the right and was forcing itself in and under the follower?

[1911Tuner]

OK, tell me where I went wrong.

My theory when I read this last night (through sleep deprived eyes) would have made the problem worse. I was thinking the slide stop wasn't protruding into the frame far enough to the right and the follower was skipping over the end of it.

If I read you right, it was too far to the right and was forcing itself in and under the follower?

Not quite, mah fren...

The combination of follower geometry and slidestop location was causing the
stop to push the follower slightly forward and to the right...and in turn, the follower was pushing the slidestop to the left...just enough to put the edge of the follower shelf on the very tip of the lower corner of the stop's lug. 9 times out of 10, the follower pushed the stop into engagement without incident. One in 10..or a little less frequently...it climbed over the edge, failed to lock the slide, and hung the magazine up.

[garrettwc]

OK, got it.

[1911Tuner]

Ran down to the range early today...around 0700...to see if the mod bore fruit. Happy to report that all 72 of my range mags were tested in the Norinco for last-round slidelock..twice each. Not a single failure. HALLEUJAH! Sweet success! :D

[runt]

Ran down to the range early today...around 0700...to see if the mod bore fruit. Happy to report that all 72 of my range mags were tested in the Norinco for last-round slidelock..twice each. Not a single failure. HALLEUJAH! Sweet success! :D

72 range mags? damn.
you don't happen to have any gi spec mags you're willing to part with, do you?

[1911Tuner]

72 range mags? damn.
you don't happen to have any gi spec mags you're willing to part with, do you?

Got a few... :D but I won't part with'em. ;)

[John]

Now, let's see:

72x2x2=288 mag fulls
288x7=2016 rounds
2016/50=~40 boxes
40x25=1000 Euros or the equivalent of 1250$

That's how much this fun trip to the range would have cost me!

I got the chills just by thinking about it!

[runt]

Got a few... :D but I won't part with'em. ;)

crap, i can't find any locally that they don't want an arm and a leg for, and i don't want to order from someone online that i can't trust to tell the truth.

[runt]

Now, let's see:

72x2x2=288 mag fulls
288x7=2016 rounds
2016/50=~40 boxes
40x25=1000 Euros or the equivalent of 1250$

That's how much this fun trip to the range would have cost me!

I got the chills just by thinking about it!

actually, it is
72 x 2 = 144
144 x 7 = 1008
1008 / 50 =~ 20 boxes
or around half the price you listed. he would have had to have loaded each mag four times for the price you listed ;)

[1911Tuner]

Actually, I loaded one round per mag for the test...since all I was testin' for was fail to lock/follower climbin' the lug...but after the test, I did proceed to load all 72 with 7 rounds for my usual 504...plus the standard two mags per gun loaded hardball to clean some of the lead out.

Lemme see...504+144=648 rounds of the cheap stuff...At about $4.00 per hundred=$25.92 plus 56 rounds of the high-dollar reloaded ammo at about 12 cents a pop for another $6.72...for a grand total of...Aw, hell...let's round it up to 35 bucks. :D

John...You REALLY need to move! ;)

[runt]

Actually, I loaded one round per mag for the test...since all I was testin' for was fail to lock/follower climbin' the lug...but after the test, I did proceed to load all 72 with 7 rounds for my usual 504...plus the standard two mags per gun loaded hardball to clean some of the lead out.

Lemme see...504+144=648 rounds of the cheap stuff...At about $4.00 per hundred=$25.92 plus 56 rounds of the high-dollar reloaded ammo at about 12 cents a pop for another $6.72...for a grand total of...Aw, hell...let's round it up to 35 bucks. :D

John...You REALLY need to move! ;)

where do you get .45acp for that price? its $11+ a box of 50 where i live :(

[garrettwc]

where do you get .45acp for that price? its $11+ a box of 50 where i live
My guess is our boy Tuner is on a first name basis with the folks at Dillon Precision. :p

and 72 mags is light. He didn't even get into the big footlocker. :D

[1911Tuner]

where do you get .45acp for that price? its $11+ a box of 50 where i live :(

A pair of Lyman 4-cavity gang molds...a former step-son whose father-in-law
ramrods the Forsyth County garage and gives me more wheelweights than
I could ever use...and a bud at a plumbing supply house who gets my 50/50 bar solder for me at cost. Powder in 8-pound kegs...3 at a time nets me a discount...and 30,000 primers at a time from a jobber nets another one. ;)

And I load on a single-stage press...

Garrett...You been nosin' around in my footlocker? :D

[John]

I am still shocked, even at half the price.

[1911Tuner]

I am still shocked, even at half the price.

Over your cost...or mine? :D

[John]

Mine Johnny, mine!!! :(

[runt]

Mine Johnny, mine!!! :(

move to a country that doesn't rape you on price?

[John]

If the price of ammo was the only thing that we have problems with in Greece, I won't complain. Not only is ammo too expensive, but reloading is also forbidden. Primers are equalized to detonators by our law, so if you are caught with them, you are considered a terrorist. Go figure!

Unfortunatelly, at almost 50 years old, it's kind of difficult to relocate, no matter how much I want to, or how many times I have thought about doing so.

[Pappy]

Not only is ammo too expensive, but reloading is also forbidden. Primers are equalized to detonators by our law, so if you are caught with them, you are considered a terrorist. Go figure!

Hi John. This sounds a bit foolish to me. Have a primer in your hand and you are a terrorist. But a factory loaded round containg a primer in your hand is OK. All a terrorist has to do is dissamble a legal round and he has his detonator. I know, laws can be a tangle, but this is........Well what are they thinking?
BTW, one can make a primer from a strike anywhere match tip. Beginning to vent here and, well, good luck...Pappy

[1911Tuner]

Hi John. This sounds a bit foolish to me. Have a primer in your hand and you are a terrorist. But a factory loaded round containg a primer in your hand is OK. All a terrorist has to do is dissamble a legal round and he has his detonator. I know, laws can be a tangle, but this is........Well what are they thinking?
BTW, one can make a primer from a strike anywhere match tip. Beginning to vent here and, well, good luck...Pappy

Now Pappy...You know that reason and logic don't have anything to do with it. It's policy! :p

[John]

Don't tell me Pappy, tell it to the law-makers.

[garrettwc]

And I load on a single-stage press...
Johnny you must have forearms like Popeye :p