I have been thinking about making a link with smaller holes for the barrel link pin and the slide stop post, C to C of the holes is .278 and I will try to maintain this dimension. Is this a bad idea to reduce these hole diameter tolerances?
I911 barrel link ?
- Thread starter joneb
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rcmodel
Member in memoriam
Yes, I think it is.
The link pin hole in the link should be a good fit on the barrel lug pin.
But I prefer the other hole the slide stop pin goes through to be a little loose, if not oversize.
This provided not only clearance from link interference when the barrel is locked tight in the slide by the fitted cam surfaces on the barrel lugs.
But also a little Link-A-Dink rattle room when the barrel is pulled down during feeding.
It not only allows the barrel room to self-align with the incoming round hitting the feed ramp.
But it also allows freedom for the barrel to rattle around and eject dirt and powder out of the way while cycling.
A perfectly fitted slide stop hole in the barrel link will give you a 1911 that won't work!!
And a perfectly fitted barrel shouldn't even have the link touching the slide stop pin when the gun is in battery.
It's purpose is (or should be) only to pull the barrel down out of battery after it is fired and the slide has moved to the rear far enough to allow safe unlocking.
rc
The link pin hole in the link should be a good fit on the barrel lug pin.
But I prefer the other hole the slide stop pin goes through to be a little loose, if not oversize.
This provided not only clearance from link interference when the barrel is locked tight in the slide by the fitted cam surfaces on the barrel lugs.
But also a little Link-A-Dink rattle room when the barrel is pulled down during feeding.
It not only allows the barrel room to self-align with the incoming round hitting the feed ramp.
But it also allows freedom for the barrel to rattle around and eject dirt and powder out of the way while cycling.
A perfectly fitted slide stop hole in the barrel link will give you a 1911 that won't work!!
And a perfectly fitted barrel shouldn't even have the link touching the slide stop pin when the gun is in battery.
It's purpose is (or should be) only to pull the barrel down out of battery after it is fired and the slide has moved to the rear far enough to allow safe unlocking.
rc
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BBBBill
Member
That sort of depends on what dimensions you have on the barrel and link now, and how well the link is working relative to the standing lug, and how well the barrel fits in battery given the specific intent of the gun.
GI spec link holes are - small end diameter .1565"+.001", large end .2045"+.001", and center to center .278" made from 1045, ASTM A576, AUSTENITIC GRAIN SIZE 7 OR FINER, AUSTEMPER; RH C 40-47. Link pin .1555"-.001" made from DRILL ROD, O2, ASTM A681. Pretty good starting point for a GI spec fit. There needs to be some clearance in the holes. Small end should have just enough to allow free movement as it pivots on the pin. Large end needs a little more clearance to do its job correctly when handing off to the bottom lugs during link up. What are you trying to accomplish? Match fit, a little better accuracy, compensate for wear or an off spec part/parts?
Links machined to tighter specs are available from the aftermarket in standard c to c as well as +/- dimensions.
GI spec link holes are - small end diameter .1565"+.001", large end .2045"+.001", and center to center .278" made from 1045, ASTM A576, AUSTENITIC GRAIN SIZE 7 OR FINER, AUSTEMPER; RH C 40-47. Link pin .1555"-.001" made from DRILL ROD, O2, ASTM A681. Pretty good starting point for a GI spec fit. There needs to be some clearance in the holes. Small end should have just enough to allow free movement as it pivots on the pin. Large end needs a little more clearance to do its job correctly when handing off to the bottom lugs during link up. What are you trying to accomplish? Match fit, a little better accuracy, compensate for wear or an off spec part/parts?
Links machined to tighter specs are available from the aftermarket in standard c to c as well as +/- dimensions.
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Thanks rc, I was digging around in garage and found a stamped dbl. open end wrench that is .140" thick. My file did a bite and skip, so I torched it to a bright orange and the file cuts it with ease. How much temper should I use after the link is finished and re-hardened blue, purple, straw???
rcmodel
Member in memoriam
Who knows??
It's mystery metal unless you know exactly what steel it is made from.
Anyway, I've been doing this stuff for a very long time.
And I wouldn't attempt to make a gun part and heat treat it out of mystery metal unless there was no other recourse, and my life depended on it.
If the homemade barrel link breaks in the right place at the wrong time?
It can badly scar up the frame, or barrel with the jagged crystallized ends gouging chunks out of them.
It just wouldn't be prudent to save $4.95 for a known quality barrel link from Wilson, Brown, or other.
rc
It's mystery metal unless you know exactly what steel it is made from.
Anyway, I've been doing this stuff for a very long time.
And I wouldn't attempt to make a gun part and heat treat it out of mystery metal unless there was no other recourse, and my life depended on it.
If the homemade barrel link breaks in the right place at the wrong time?
It can badly scar up the frame, or barrel with the jagged crystallized ends gouging chunks out of them.
It just wouldn't be prudent to save $4.95 for a known quality barrel link from Wilson, Brown, or other.
rc
BBBBill
Member
See my above edited post. The original material was 1045, but modern manufacturers use much better steel. 4140 chrome molybdenum or 416 stainless heat treated to RC 39-45.
Food for thought. Kart provides an oval holed link on their EZ-Fit/Exact Fit match barrels. Instead of a consistent .203" hole the hole is elongated to .209" on the long axis.
But I agree with RC. Lots of things that I enjoy spending my time doing on a 1911. Making a link would be way down the list unless I was bored and just wanted to check that box. Then it would be using pre heat treated material, my rotary table on the mill, finished off with the surface grinder.
Food for thought. Kart provides an oval holed link on their EZ-Fit/Exact Fit match barrels. Instead of a consistent .203" hole the hole is elongated to .209" on the long axis.
But I agree with RC. Lots of things that I enjoy spending my time doing on a 1911. Making a link would be way down the list unless I was bored and just wanted to check that box. Then it would be using pre heat treated material, my rotary table on the mill, finished off with the surface grinder.
stu1ritter
Member
The link in my Mike Curtis accurized 1911 has a +3 stamped on it. What does that mean if I have to replace it?
Thanks,
Stu
Thanks,
Stu
BBBBill
Member
+3 indicates that the link is nominally .003" longer center to center than the standard .278" link, i.e. .281". I say nominally because the manufacturers are typically not that tight with their manufacturing. So it might be .281" or .280" or 282". Best practice in your specific case is to let Mike fit the replacement. Last I heard he will still maintain the guns he built. Failing that get another qualified bullseye smith to fit the new link. It is very important that the most minute details be addressed in a finely fit bullseye pistol. For anyone else remember that individually fitting beats "drop in" all day long. Never trust the packaging or the manufacturer hype.
stu1ritter
Member
I'll ask Mike but I don't believe he is working on any civilian guns since he joined the BATFE.
Thanks for your explanation BBBBill
Stu
Thanks for your explanation BBBBill
Stu
Coyote3855
Member
I'd spend the $14 just to save all the effort, and eliminate the possibility of a failed part that could damage a $1000 gun.
Wireman
Member
joneb, could you fill in your question with a few more details? I can't figure out what it is you are doing and why. It sounds like you want to make a link with smaller diameter holes than the standard link. If so, what is your end goal by doing that?
WM
WM
243winxb
Member
Wilson Combat Custom Barrel Link Kit 1911 Stainless Steel ?
Wireman
Member
I have to admit I am stumped. You want to make a link? What improvements are you expecting? The first part of the question is whether you are making a GI-spec gun, or an improved performance gun. If it is a GI gun, you don't have to worry a bit about the link because your barrel will not be fully supported anyway. If you are trying to make a zero tolerance gun, simply reducing the tolerance of every part and every hole will get you a pile of expensive parts that won't work. Think about this fact: the link unlocks the barrel - most people agree on this point. But the link also takes the barrel back up into battery. Performance guns make the barrel lugs stand on the slide stop pin for a hard lockup, but the link is what gets it to that point. It is not possible to make a link and a cam work simultaneously. The slide stop pin does not ride the lug radius to push the barrel upward. The slide stop pin can meet the barrel lug at the last .030", but it does not ride the lug into battery. That's the way it is.
WM
WM
Actually, the link doesn't "get it to that point." The link is not necessary to get the barrel back into battery and, if it is too short, can actually prevent proper lockup. That is why folks are saying that there needs to be some play in the link so it doesn't interfere with the barrel foot camming up onto the slide stop.
Jim
Jim
Wireman
Member
When you say "get it to that point", I have to disagree. Of course there a 2 possible ways that the barrel can begin its forward movement into battery. One is if the hood touches the breech, then it is the breech that pushes the barrel forward. If the hood does not touch the breech (GI or tactical tolerance gun) then the breech blocks bear against the barrel's recoil surfaces and push the barrel forward.
The upward movement of the barrel is controlled by the link. It is written in various manuals that the slide stop pin "cams over the barrel lugs" to bring the barrel upward, but this statement is false. A link and a cam cannot work simultaneously. If there is slide stop-to-barrel lug contact at this point, you have an unreliable gun. This situation is not the fault of play in the link. It is a mistake in the proper cutting of the barrel lugs, vs link length.
So, in fact, in a properly fitted improved tolerance gun, the link actually does get the barrel 99% of the way into battery, at which time the slide stop pin and the barrel's lugs can meet to secure the barrel into a tight lockup. In order to make it work this way, the lugs are not cut using the link pin center. They are cut using a center that is offset a little towards the rear. That small change in centers is what prevents the slide stop from crashing into the lugs.
WM
The upward movement of the barrel is controlled by the link. It is written in various manuals that the slide stop pin "cams over the barrel lugs" to bring the barrel upward, but this statement is false. A link and a cam cannot work simultaneously. If there is slide stop-to-barrel lug contact at this point, you have an unreliable gun. This situation is not the fault of play in the link. It is a mistake in the proper cutting of the barrel lugs, vs link length.
So, in fact, in a properly fitted improved tolerance gun, the link actually does get the barrel 99% of the way into battery, at which time the slide stop pin and the barrel's lugs can meet to secure the barrel into a tight lockup. In order to make it work this way, the lugs are not cut using the link pin center. They are cut using a center that is offset a little towards the rear. That small change in centers is what prevents the slide stop from crashing into the lugs.
WM
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