Tuner: Loose Barrel Link Pin - Problem?

[RugerOldArmy]

Tuner, if you would be so kind. I'd appreciate some 1911 advice.

I've got a loose barrel link pin on an old mutt-1911 of mine. I've grown quite fond of this mutt (colt slide/barrel, springer frame), it even shakes off drops of oil on the first shot, just like a wet dog.

However, as I cleaned it, I noticed that the barrel link pin was loose. Too loose. It could have been some excess gunk from those lead-free patches dissolving some bluing, or it could be wear. Dunno if the pin wore, or the holes the pin fits into.

Could I use a regular stainless pin, cut to length for a repair? Weld on a little metal to tighen the hole? Or is this a critical, stressed part, and should I get a drop-in replacement barrel/bushing?

 

[1911Tuner]

Loose Pin

Howdy Ruger,

The answer is...it depends on what made it loose. If the pin wallowed the hole in the lug to an egg-shape...it's a problem. If the pin just wasn't correctly press-fit in the hole, it's likely just opened up the hole to the point that it lost its interference fit, and an oversized pin will probably take care of it. The hole may need to be reamed to just slightly under the pin diameter to get a press-fit.

Some smiths will stake the area around the hole to keep the pin from falling out
during a field-strip. I don't like to do that except as an expedient rapair until the problem that caused it to get loose can be corrected...because if it's not, it'll just do it again later on...and then you may have real problems if the hole can't be trued up and reamed for another pin. Generally...you're limited to reaming to .155 and using a .1565 or .157 pin...and you'll have to make a .157 pin from drill rod.

There are a couple of things besides incorrect press-fit that will cause the hole to wallow out. Locking tightly on the link is one. Incorrect specs between the frame's impact surface and rear of the lower lug....which causes the barrel to stop on the link instead of on the frame bed...is another. If the impact surface in the frame is too far rearward...or the rear of the lower lug is too far forward...That'll do it too, though that one usually stretches the link.

Use a dial caliper to check the hole in the lug to see if it's out of round...and how much. Check to see if the barrel is locking hard on the link. I see that one a lot whenever somebody installs a long link in order to tighten the vertical lockup at the barrel hood. Slip the slidestop crosspin through the link when it's vertical...in the locked position. If the link keeps the crosspin off the lug by more than just
about the thickness of a sheet of paper...there's your bug. Ideally, the crosspin should lightly contact the lower lug from the forward radius all the way into the barrel feet...but many production guns aren't correctly fitted in that area these days. A tiny bit is probably okay...A lot ain't.

Check these things and report back.

Standin' by...

 

[RugerOldArmy]

Tuner, You're like talking to JMB himself.

Visual inspection of the barrel link hole: Looks round, or very close to it. No bluing missing on the inside of the barrel link hole in the barrel lug. (lower).

I really can't measure it well with the calipers (I only have Lyman digital calipers, for reloading, better for measuring OD, than ID, on so small a hole, so I'm not confident in an absolute measurement using the ID portion, but it seemed that it is within .002 of round as a guess.)

Interestingly enough, the barrel link pin width is .153 on the two areas it touches, and .154 to .155 in the middle, where the link is.

Close scrutiny, wear on one side of the lower barrel lug (I assume this is the term. You know, that the pin goes through, and I assume it nestles in the frame.) Bluing worn away just a bit. on the lower left side. Just a bit evenly on the lower back of the lug. The frame shows no wear.

"Check to see if the barrel is locking hard on the link" I'm just your average redneck here Tuner, dunno what that means. You mighta lost me on this.

Wait...maybe I figured it out. You said:

"Slip the slidestop crosspin through the link when it's vertical...in the locked position. If the link keeps the crosspin off the lug by more than just
about the thickness of a sheet of paper...there's your bug. Ideally, the crosspin should lightly contact the lower lug from the forward radius all the way into the barrel feet..."

Well, this is more than a piece of paper. Maybe two business cards, and not evenly (wider gap (say 3 business cards) around the slidestop near the bottom).

Since this is the barrel lug, and as you said the root cause, am I off getting an Ed Brown Drop-in Barrel/Bushing combo? (If you have a better option, do tell...)

BTW, this is the first I noticed it is loose, and it slips 'freely' in and out of the hole. It shot maybe 400 rounds flawlessy last time I took this puppy for a walk. She's had 5K-ish through her, in her mutt-like condition.

I know I can't shoot it till this is resolved. (Thank god for the TRP as backup!)

Tuner. Thanks. Thanks very much for the detailed reply.

 

[RugerOldArmy]

Tuner,

I think I know where this was going. I bit the bullet and ordered this drop-in barrel & bushing combo. This should address the problem the right way, no?

Thx

 

[1911Tuner]

Bit the Bullet

Howdy Ruger,

You mighta jumped too soon. The problem likely could have been fixed with a
new pin. Looking at the hole to check for being out of round is next to impossible unless it's REALLY out. You won't see .002 inch unless you've got better eyes than I do. About the most I can detect without measuring is .005 inch or so.

Check your PMs

 

[Dave Sample]

As long as you are doing it, install a new link and pin using the standard .278 link (Number Three). I always stake these pins in because I think it is crude not to. They tend to fall out and get lost and I am really tired of crawling around the floor in the shop looking for them. I stake them in on both sides. Adding new NM bushing will give you about as much accuracy as a new barrel. It is nice when they are a great press fit like the Kart Barrels we use, but most of the time factory barrels are not pinned tight enough.

 

[Jim K]

Hi, guys,

Dave, I know what Tuner is saying, but I stake them too. The specs for the pin show a radius on the ends just for that purpose. Like a lot of stuff, the tolerances of the hole and the pin can work out so the pin is a drive fit or so that it is a slip fit. Except on a gun to be used a lot, I don't worry overmuch about a slightly loose pin.

Jim

 

[Dave Sample]

I got you, Jim. Unlike a lot of people that mess around with 1911's, I do everything I can to insure that they will work. I would not take a gun in if I thought for one minute that I didn't have time to do all the things they need. I do things that other smiths say is not needed and for their work, that is fine. It's just not good enough for me. I may take in junk, but when it leaves here, it is the best junk around. Not everyone can afford the kind of Custom 1911's I used to build, but if they can afford a 1911 of any make, they can afford a reliablity tune up that was $75.00 in those days past. I stake the hammer stut pin, I stake the barrel link pin, and I also Red Loc-tite the overtravel stop in the trigger after I adjust it. I even polish the hole that the mainspring rides in. That is the difference between me and some of the others we know.

 

[RugerOldArmy]

Thanks very much to all for the replies. I feel a little bad to have gotten some good advice, and just replaced the barrel. However the reputation of Nowlin, the security of new parts(barrel, bushing, #3 link, oversize hardened pin), the promise of better accuracy from a tighter barrel/bushing and bushing/slide fit are appealing, and this is already a project gun of sorts.

I think Tuner's post, and some wear on the 'barrel feet' lead me to question the geometry a bit.

Although it may be academic at this point, I'm interested in what Dave Sample meant by 'staking' the pins. Is this a pin in a pin? Or 'peening' the end of the pin, so it bulges a bit, for a tighter fit?

Thanks again!

 

[1911Tuner]

Staking

Nope. Staking a link pin involves using a sharp punch to displace metal on the lug
around the pin hole to keep the loose pin from falling out during a field-strip. It
does keep the pin in, but does nothing to prevent the pin from eventually wallowing the hole out when a condition called "Riding the Link" exists, in which the barrel pivots on the link upward and into battery instead of correctly being cammed upward by the slidestop crosspin. The enlargement of the hole will occur more rapidly if the barrel is also "standing" or locking on the link...depending on how tightly it's forced into the slide, regardless of whether the pin is press-fit or not. It will just occur more rapidly if the pin is loose to begin with.

Obviously, the problem is brought on by the above mentioned conditions, and is a
spec/fitting issue...and unless corrected can and will lead to premature wear and battering of the link's hole in the lower lug. It wouldn't be necessary for the barrel to be hand-fitted if the specs and tolerances were to be more closely adhered to during manufacture.

Lately though...in the past 5 years or so...I've noticed that there is less and less of a problem in the lower lug/link area than in the previous 20. Springfield, especially has been paying closer attention to this, and their factory lugs and links...from the entry-level GI Mil-Spec to the top grade pistols...have been very good in the problem area.

I never stake link pins except as a field expedient rapair. I much prefer that the
pin be press-fitted with at least a .001 inch interference fit...and .002 if at all possible. This requires that the pin be left in a freezer overnight, and the barrel heated in an oven to about 150 degrees for an hour prior to the press-fit. This
allows the pin to enter the hole with a little effort without danger of deforming the lug, and when the parts come to room temperature, they're there...and even if the
barrel is riding and/or standing on the link, the procedure will greatly delay the wallowing out of the hole and subsequent change in barrel linkdown timing caused
by the sloppy fit.

Note that staking a loose pin is perfectly acceptable in a pistol that won't see heavy use. A carry gun that is only fired occasionally will do well with a staked pin, provided there isn't excessive slop between link and pin due to an elongated hole.

Think of it as being similar to excessive clearance between a crankshaft throw and a connecting rod bearing. The engine may do well for a time, but the slam-bang will quickly beat the connecting rod insert into an oval-shape. Knock-Knock-Knock...

Hope this clears it up for ya.

 

[Dave Sample]

Good post by Tuner, as usual. I know it is reduntant to say, but try and remember that I do very high end work on 1911's. I have done my share of "Factory Gun Tweaking" as most real pistolsmiths have to do. I much prefer a press fit to staking, needless to say. Our Online 1911 Patriots have Kart EZ fit barrels with the link and pin press fit by Fred Kart and we leave well enough alone there. Our guns are top quality parts and we fit everything very slowly and with great care. This is called learning to do things the Captain Eagle or Dave Sample way. The finished product speaks for itself. We are called "Parts Assemblers" by the REAL Machinist/Pistolsmiths and I have no problem with that. The only problem with that is that my students do a better job than most of them do tweaking their factory guns. It is another case of Apples against Oranges. They do what they do and we do what we do. There is no conflict there that I can see. I do not teach any remote form of "Gunsmithing" a 1911. We teach people to build one very nice 1911 from parts. Period. That experience, however leads to aquired skills and knowedge that will serve them well after they complete the task at hand. Tuner and I do not share the same place in the 1911 world and I am sure he is as glad of that as I am. Viva La Difference!



We put our 1911's in the Shot Show for all the gun guys to see.



Hey? Who's those people with Dave?

 

[1911Tuner]

Redundant

Understood Cap'n...Allow me to once again travel down Redundant Boulevard and remind one and all that I don't do high-end custom guns....neither asembled from parts nor refurbished and blinged. I'm a mechanic...A salvager of wrecks and busted things...A tuner of miscreant, malfunctioning sidearms...and finally, a repairer of wallowed-out holes in lower lugs. If a press-fit is called for, then it's gonna be a press-fit if I have to ream the hole oversized to get it round and make a pin for it. After all...it's the right thing to do.

That's about all that I've done, and all that I ever will do. I've snatched a couple of the Top Guns' creations from the depths of despair, and was shocked at what I saw during the repairs. made a few silk purses out of sows
ears, but you wouldn't know it to look. Ya gotta go shoot'em...a lot. Pretty is only skin deep, after all...but ugly goes clean to the lockin' lugs.

Cheers and all that rot.

 

[P95Carry]

GREAT - GREAT thread!!! Dave, Johnny - excellent reference material. Glad I found it - good read and thx from a 1911 greenhorn! Still learning - doubt it'll ever stop.

 

[Dave Sample]

hey Tuner! Ain't you glad we is us? I am! Onward and upward, old pal.