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I'm diggin' the closed-off side ports with the new barrel. the look has a certain industrial/steampunk appearance to it. Leave it to Ned to to a replacement/repair and turn it into art.

Thank you Patrick. You are forgiven for disliking the Shield Driver sight

Off-center firing pin holes- As mentioned in a recent post (Page 8 of this thread, Dec 22), this is practically a given in guns shorter than a Commander. Manufacturers could totally make this go away but I think that because "most of the time" it's not extreme enough to lead to misfires, they get away with it. The barrel is shorter but nothing is changed about the slide bore that locates the front of the barrel when in battery, so as the barrel locks up, it tips 'down" more than in a G-Model. As it does the rear end also tip up a little-- low firing pin strikes are common in these, although again, it has to be radically off center to cause misfires. I have not purposely tried it but I would guess that off center plus a 9mm-sized firing pin that is quite common, plus the Speer ammo with small primers, would be the misfirin'-est combo.

In any case, when it has to be fixed, outside of a radical mess=around with the barrel, the fix is a bushing. How far doe the FP hole have to move sometimes? A lot:



This FP hole is on-center with the chamber within a couple thousandths, not gonna reveal my exact method but it puts the hole right-effing-there. The question becomes, do you but in a blank bushing and then drill the FP hole perfectly aligned with the bore axis, or do you make the bushing hole on center and then make the bushing with the FP hole in the center of it, the install the bushing? I prefer the latter.

When things are this eccentric, it's beneficial to use a 9mm FP, otherwise there is more likelihood of the FP binding in the misaligned holes. In the pic you can see that after installation, I went in the firing pin hole from the back with a flat-bottom drill to make sure that the back of the bushing and the original hole present a flat enough surface to the firing pin spring to land squarely in, otherwise it might contribute to binding.

My head hurts just thinking about how this was done,and what the FP has to go through, to squirm through the breechface to the primer.

The .50 GI pin gun ( https://forum.ltwguns.com/viewtopic.php?f=6&t=9890 ) with the compensator made of Delrin, as expected, has suffered some erosion. It’s a two-chamber comp and I had already installed an aluminum flanged bushing on the first blast face, that was really taking the brunt as expected. Well that eventually got damaged when an ejected case bounced off of something and landed in the rear chamber—just as the trigger finger had been given the “fire” command. Damage was not catastrophic and it would have been good for another season of pin shooting but—I was asked to bring it back up to par. This is the process in small part.
Boring the first chamber back to a known dimension—just cleaning it up 90%, really. The flame erosion pattern was interesting and you can kinda see it here—the axial washouts correspond with lands, and not grooves, in the barrel (these are eight-groove barrels). This pic makes it look like the Delrin is threaded but those are just the pass-though holes for the cap screws that hold the comp to the barrel extension, that have been marked by the screws.

Starting the aluminum sleeve that will line the rear chamber.

Lots of chips….. 7075 aluminum.

Sleeve finished and installed at a light press fit… now two slots are milled for little keys to be dropped in and sandwiched between the Delrin comp and the aluminum barrel extension. These will keep the sleeve from rotating and from moving upward, which I don’t think it would do but when you fire bullets through things by the thousands, the unexpected does happen.

More to be done, but sofar, so good. You can see some of the remaining flame erosion where the aluminum and Delrin meet at the top. I just didn’t want to bore out enough Delrin out to clean it up. I see it like a patch on a Spartan’s helmet—“OK, this guy has seen some battles.”. And it is very true of this .50 GI pin gun!

The front blast face was also getting significant erosion, again as expected, but I think it can also be taken as an indicator that the second chamber and blast face are doing some work. If gas and particulates are hitting it hard enough to erode it (even though it's just Delrin), it's pushing the muzzle forward / down to same degree. So the blast face resurfacing plate is not 7075 aluminum, it's the soft gummy stuff. But it will hold up better than Delrin and anyway I made a spare. It is held on with four, 5-40 alloy button-head cap screws and aircraft locknuts. I think we're good for another 5-10,000 rounds of .50 GI goodness. Bowling pins beware.

It's like Christmas when I see a new post in this thread from Ned. What has the mad scientist come up with now...

Thanks Bill! Great having you as an onlooker.

Delrin comp epilogue-- for now. The sleeve is rock solid in its installation into the Delrin body. It can't move in any direction, nor rotate. But is was easy enough to add a little more insurance, so, a couple of those 5-40 button heads were installed, one on each side. Drilled and tapped into the aluminum sleeve and the Delrin around it, they go in with some red Loctite, and get ground off flush inside with the Moto Tool. Not the neatest work there but very soon the whole area will be covered with burnt powder soot and lead buildup. I thought about various ways to mechanically lock down the front of the sleeve and arrived at this since this way IF the screws were to come loose, they would fall out of the comp and not into it. As a final hedge, I made a little piece that got heated up with the torch and brought down precisely on the screws' locations, melting the Delrin and deforming it over the screw heads. Those screws are staying put, pretty sure. But again-- everything in a gun, especially in a comp, takes a vibratory jolt every time the thing is fired. That's why guns crack, why screws come loose.



A few more little things to squeeze in over the w/e and then we return to our regularly scheduled program.

Many, maybe most, of my customers are on the high-volume side. TC got this back together today and put 520 rounds of .50 cal 270-grain SWC's through i:

Time waits for no…. Coltwood grips. The years have taken their toll on these 1968 grips. They have shrunk to the point of cracking and elongating the grip screw holes. As a former moldmaker I know that plastic does shrink—when we make a mold, everything has to be scaled up for example, ABS is usually 1.006, in other words, if you need a 2” dimension on the plastic part the cavity has to be cut to 2.012. But it also shrinks more, very slowly, “depending”. These sure did. 1968 .38 Super.

A good idea at the time.....

But then, had G10 even invented by 1968?

G-10 was introduced in the 1950s, first used in printed circuit boards. Micarta, very similar, introduced in the eary 1900s.

I had occasion a few months ago to put a couple file strokes on some gutta percha grips and did some research on it, interesting material and history and applications "way back". I remember an episode of The Wild, Wild West where a supposed sea creature was found to be made partially of gutta percha and I never forgot the term. In my little-kid mind I wondered, since it was a sea creature, if this gutta percha was maybe made from perch guts..?!

The gutta percha filings smelled like Vegemite. That is not a compliment to gutta percha. I did not attempt to taste the filings but they can't have been worse than Vegemite.

Getting old grip bushings out. I’ve done it a variety of ways but this time I wanted to try something I’ve been thinking of. I made a step drill out of a .191 (#11) drill, grinding a .125 pilot on it. .125 just passes through a grip screw bushing. Using this I can drill the bushing’s middle out and be pretty sure I’m dead center without an elaborate setup. Then, in with an easy out. The thing with this old Colt that kinda tipped it for me was that they were the original bushings and had very substantial, 8-point stakes. The bushings were not going to come out easy—and generally they are not made of very strong stuff—they are the mildest of mild steel, so the slots might well give way before the bushings turn. Anyway I did not want to drag those extreme stakes back out through the frame's threads. Well this way they did get dragged through but at that point they had been drilled and the wall thickness left was so thin that they just collapsed in diameter and came out real easy.

On the previous page of this thread, Page 10, 3/4 of the way down, I put out some comments on frame to slide fitting. I'll say again (because I just did it again) that the recutting of both the frame and slide, the cutting is the easy part (but not that easy). When you have a frame and/or slide whose exterior is done the old way, basically sanded / polished / buffed by hand, you have a finish that can look really good but it's far from flat. There's nothing wrong with frames and slides done that way until you want to hang onto it somehow for further machine work; some of that work it honestly doesn't matter too much if it is performed on a frame or slide that is flexed .005 in an effort to hold it securely, let's say as an example, holding it to FRAG the front strap. But if you are holding them to cut slide and frame channels that you want to mate with each other all straight and parallel and with minimal clearance, you can't just clamp them up to something or in something, because they will flex. Then when you're done cutting, and unclamp them, they will unflex and your nice straight cuts will unflex with them! Sometimes the slide and frame rails are far from straight from the factory and sometimes it's for the very same reasons: when they clamped it for cutting, it flexed. On a recent one, the slide rails were uncommonly straight and parallel until the last 1 1/4" at the rear, where the rails took a distinct turn to the right! Both sides, all vertical surfaces went right in perfect unison, to the tune of .005, so everything was parallel but not straight.

It's easier when the slide and frame have been surface ground and are straight and parallel within, usually, something like a half thou. Many of the more recent brands are done this way. Could you take a wavy slide and frame, and surface grind them flat? Yes, but it's not practical. You will lose some rollmarks probably-- I say that having seen slides and frame whose thickness varies .010 or even more. That means you're going to grind them at least .010 thinner and that will lead to other problems. Because both parts are so hollowed out, in grinding they will be very sensitive to heat from grinding and a generous coolant flood is necessary. Other work-arounds are preferred.

Yep. Understood. Brands don't seem to matter, although the few JEM frames that I've built on have been far more uniform than any others. Looking forward to trying a JEM slide.

Saturday I ran across this custom m1911 from Ogelsby & Ogelsby, from I think about 1994. Sawtooth serrations on top, soldered-on frontstrap checkering. Was that a repair or just the way he did it? Very prickly and effective 60° points; gun worked fine.

I had a chance to do a detailed go-through of the gun from the “High Mileage Comes To Town” thread in last week’s Patrol Rifle class.

"High Mileage Comes to Town":

https://forum.ltwguns.com/viewtopic.php?f=6&t=8365 (unfortunately, some of the pics have evaporated)

I have written much about the owner, who is a serious competitor, recently retired police Chief and a police firearms instructor of renown. He is today’s Bill Jordan / Jeff Cooper / Jack Weaver: a real, true 1911 lawman / 1911 guy through and through, not because it’s “cool”, but because that’s what he does and has always done.

First, get the barrel nice and clean inside and out so the inspection can be done…. Chore Boy copper pan scrubber on a Nylon brush. Beware the version that is steel / copper plated. Take a magnet to the store with you


The barrel was fitted so that all three lugs “pick up” some of the load. This results in a longer lasting fit and increased safety (my opinions). Also there is no “flanging” of the locking surfaces. Either they are not moving at all or sometimes flanging that does occur also gets wiped off in cycling. Jeff often comments on the accuracy. Kart barrels, whaddya gonna do.


The three-lug sharing of the load can also be seen in the slide’s locking recesses. Without machining the barrel locking lugs to match the slide, most guns will lock up on one. One of the others might be say .003 gapped from locking and the other maybe .008 or some variation of this. In .45? “good ‘nuff” but all three touch is “betterer”.


Bore looking good and is holding up well to the miles. Info as to round count is expected soon. This new top end—slide and barrel-- was completed in late 2018.


Cases are wearing their shape into the extractor, as I have seen before on this and a few other high-milers. This is the EGW extractor and it seems to be taking the punishment well. The two dots signify extractor #2 of the two provided with this rebuild. I didn’t get a chance to ask what happened to #1 but Jeff has broken more 1911 extractors than anyone I ever knew—and also shoots more rounds through the same 1911 than most people go through in a lifeltime.


Breech face topography—again! Jeff’s guns have it more than most. And a little pitting is starting around the line where the primer OD and primer pocket ID meet in a press fit. I think priming compound these days is more brisant and this is the result. I think. This breech face will soon get the stoning treatment as the bumps eventually will create an impediment to good feeding.


Slide stop notch peening. The surprise is that it peens on the back stroke, on the angled front side—seems like it wouldn’t, so much. I typically chamfer these edges a little but the round count has caught up to it…..


Pickup rail, AKA disconnector rail, is still nice and smooth:


Someone please count the dings. That times 7 will be the round count since the rebuild…..


Jeff has been known to wear out parts that no one ever thought would wear out, like a mag catch that has worn so it holds the mage maybe .015 lower and causes feeding issues on occasion. This one still looks good.


The original work on this gun is from 1996 I believe. Maybe about 2015 I welded up some cracks and the weld shows in a few areas but has never re-cracked.



Inside the magwell, a hard area to clean. In the sharp corners, some crud buildup everywhere a magazine “ain’t” but no reliability hit. My Extra Stout Plunger tube and its four bosses can be seen here.

FRAG grips on the inside. Some sooting where the frame lightening cuts are. Oops, I said FRAG, I meant ORIGINAL EFFING FRAG


I always say, the feeding profile doesn’t need a mirror finish, it needs to be dimensionally and geometrically correct. This one has a little divot low right from, I don’t know, a certain kind of mag follower I think. But it continues to work well with duty ammo and 200 grain HG 68’s.


Bowtie cut still bowtie-in’. The recoil spring guide is getting banged into the recoil abutment some—totally normal at high round counts.


Colt MIM’d sear and disconnector! They are actually—really good stuff. As with any process it can be done well, or not well. I've always had good results with these.


Welds in evidence. At that time I did not have laser welding. It was harder to get everything to blend perfectly; you could make it disappear in polishing and blasting only to have it show again after bluing. This one was blued BTW by a retired Chicago copper whose legend I learned years before I met him. A real character to be sure, with lots of stories from the old days of big city policing. Crime was less of a problem in those days. BTW as a tourist in Chicago, many, many times (but no more), I met CPD guys in the street. Before I had any affiliation with or knowledge about police. Just another stupid tourist. All of them, each and every one, treated me very well. Good times when a weekend in Chicago was fun and pretty darned safe.

Nice to see the history shown in the wear patterns. Obviously well used and well loved.

Indeed it is. Talk about an EDC..... all day every day.

I edited the post as to when the cracks were welded, it was before the new top end, like 2015. Also rereading it, some comments come to mind.

That EGW extractor form, I think, ought to last longer than the standard flat blade shape, but we won't know for sure for another five years I guess. It is quite certainly easier to manufacture and that's not necessarily a bad thing for the end user. Is it softer than it should be, given the wear in the claw area? I have seen that on "regular" extractors too.

The wear on the breech face has not changed much from the 2022 pic. I'll ask as to round count in the interim but I've never known Jeff to have a lull in his shooting volume. I think it is more an issue that any kind of wear or damage, starting from new, makes itself evident quickly and then slows down sometimes almost to a stop. Example, if I take a 2X4 and swing it at another 2X4, corner to corner, it's going to leave a mark on both. If I do it again, it will get a little deeper, but in the next 100 whacks it's going to get to a point where additional damage is undetectable.... although yes, if I do it 20,000 times more there will be additional damage.

THis info is just so fascinating. Thanks Ned!

Talking about brisant primers. I forgot I'd had this convo with a guy in the ammo biz who knows these things:

ME:
"In very-high-mileage 1911's I see pitting on the breechface in a circular pattern that matches the primer diameter. These are guns with tens of thousands of rounds through them. I take this to be flame cutting from primer leakage, would you agree? Is it priming compound doing it, or from powder ignition? I'm guessing the primer is the culprit since it seems like the primer ought to obturate once we have ignition. Agree?

Also, am I being accurate when I say priming compounds are brisant?

I did a little experiment recently, part of my trying to answer why barrels that shoot only lead bullets (H&G68 mostly) still wear out (albeit only after tens and tens of thousands of rounds). On a clean white sheet of paper, I tapped fired .45 cases mouth-down so see what might break loose. Not much. I deprimed others and repeated the paper test-- not much. I primed them and retested-- a lot of black debris came out. My theory, seating the primer crushed and broke loose the crud in the bottom of the primer pocket. I'm guessing this is some hard stuff-- maybe even with a little ground glass in it? Probably behooves us to take measures in reloading to avoid putting that stuff down the barrel upon firing, agree? Primer pocket cleaning-- ew. I'll just change a barrel once in a while! My previous-and-still theory is that another contributor is tumbling media dust left in cases which then becomes part of the ejecta. I've been bad about keeping fresh media in the tumbler.



He respopnded, "no glass in CF primers", and, "yes, primers should obturate but rarely seal completely".

r.e. your comments on the MIM sear and disconnector - I have no problems with MIM if done well. I think most of the major players have figured that out by now. We were just discussing this over on another forum. My issue with it is my inability to get the feel in the trigger job that I've come to expect. I get the weight down to what I want, but it just never feels quite the same as one done with premium parts. That may all be just me. It is certainly functional and will give good service.
I do harbor a belief that MIM will wear out sooner than premium stuff. That is based on only my limited sample size, so obviously not something that I want to hang my best hat on.

" I do harbor a belief that MIM will wear out sooner than premium stuff. That is based on only my limited sample size, so obviously not something that I want to hang my best hat on........."

In my very very limited experience with parts over the years it seems service life of the part is dependent on the standards or spec when the parts were made either MIM or Tool Steel. Part of you get what you pay for. Good Quality Parts give Good Quality Performance..

_________________
Be safe and keep the brass flying

Terry Peters

Do your research but you get what you pay for front end or back end
http://www.pt-partners.com
@ptpartners_tx

Jeff has been saving and dating primer box tops and I got him last night to go into that "file" and determine how many large pistol primers he has gone through since December 2018. All these primers went for ammo for this particular pistol. That number is..... 63,500. That is the number of rounds fired through this pistol since the 2018 new barrel, slide, and slide and frame weldup.

In that time, the ejector broke and the hammer strut broke. Looks like the #2 extractor is in it not because #1 broke, but just to "share the load". The slide to frame fit is still great due to lots of contact area.

That's HUGE ammo consumption for anyone, especially in one gun! Speaks volumes about the builder, shooter, and gun. I'd say that his muscle memory is reasonably well established.

It is a lot of ammo.... but the only time he's not shooting is when he's instructing-- and he shoots quite a bit in class.

Here is the 1911 in question in its well-worn holster which is number I-don't-know-what, they get replaced rather often, and repaired in between replacements, as seen here.


Here is a much-shot AR this last week. Bore erosion gage goes clean through, end to end. Still shoots Black Hills 77's / Mk 262 Mod1 very well but keyholes with 55 FMJ....

Marvelous as always Ned!

_________________
Kentucky Colonel, Tennessee Squire & Combat Leprechaun
"You won't rise to the occasion - you'll default to your level of training." Barrett Tillman

Nice to hear from you Jeremy!

Guy brought this to class last week. Anyone know anything? .25 ACP necked down to .17, barrel for, I believe, a Colt Junior. Barrel marked ".17 Junior".

Ned I have learned so much from this thread and look forward to updates every couple of days when I drop in.

_________________
And this eternal resting place Is known as Fiddlers' Green.