Swift Links?

[Concorde]

Have any of our 7/02 folks worked with Swift Links? For those not familiar with them, They sort of look like a DIAS, but function more like a Lightning Link in that they don't require any changes to the fire control group and it's up to your trigger finger to determine how many rounds you fire at one time . Unlike a lightning link, though, they don't require the old style bolt carrier but rather work with the regular M16 style bolt carriers that come with most modern AR15s. When the bolt carrier comes forward, the swift link pushes down on the disconnector to let the hammer fall forward as long as you're still holding down the trigger.

Here are three designs I'm hoping to test (and yes, I work for an 07/02):

Of course, all NFA and manufacturing rules apply associated with post-sample machineguns.

 

[Mackjack]

Already been done before

https://ctrlpew.com/yankee-boogle-3d-printable-ar15-full-auto-mod-swift-link/

 

[A&S Conversions]

It seems like an interesting concept. It doesn't seem like these devices would last much more than a few thousand rounds. I would think that adding a metal surface for impact and spring for the flexing area would allow for more longevity. I can't see such a device being desirable to a law enforcement agency as the Swift link would have limited service life. A Swift link would also be a conversation, where Agencies like to purchase factory equipment. Agencies can get M16s from the Government via Form 10 for next to nothing so ther would be very little if any cost savings using a Swift link. To me a Swift link is a solution looking for a problem. We are applying for our 02. We have plans to make a few Post Samples, but no interest in developing an type of Swift link. Good luck with your project.


Scott

 

[chili17]

I have tried them in a RR posty and they only lasted 3 or 4 mags. Of course I made one from a coat hanger

 

[Concorde]

These wouldn't be for sale to govt/LE, but merely for demo. We've had several times where we've done demos for govt/LE of specific weapons, but we always bring out others just for grins and goodwill while we're at range for after the demo of what they're actually coming to test. The govt/LE folks always enjoy seeing, handling and shooting other weapons that don't necessarily have direct application to their department mission. I'm sure showing them what a 3D printed swift link looks like and how it works will be of interest and appreciated.

Chili -- I've seen the coat hanger version! For those of you that haven't: The Firearm Blog

 

[Concorde]

Question -- when the Swift Links start to "go bad", the hammer drops on a round but doesn't fire it -- the primer appears to have a light strike. Would this be a "timing" issue that's developed? Does that typically mean that the hammer is dropping too early, or...?

 

[A&S Conversions]

It would seem to me if the timing with the link was good and then started to have light primer strikes that would tend to be late because wear would tend to cause the hammer to be released later rather than earlier. There would need to be more material to get the carrier to press the disconnector to release the hammer earlier. On quarterbore's site for DIAS http://quarterbore.com/nfa/dias.html halfway down the page there is a paragraph about timing. I would think that the same method outlined could be used for timing a Swift link.

Scott

 

[Concorde]

Intuitively I would also think "late" for the reasons you said (material wearing, etc), but as long as the forward moving bolt has the round fully seated in the chamber, I don't see how it would result in a light strike in a "late" scenario, only in an "early" scenario.

 

[sniperdoc]

These wouldn't be for sale to govt/LE, but merely for demo. We've had several times where we've done demos for govt/LE of specific weapons, but we always bring out others just for grins and goodwill while we're at range for after the demo of what they're actually coming to test. The govt/LE folks always enjoy seeing, handling and shooting other weapons that don't necessarily have direct application to their department mission. I'm sure showing them what a 3D printed swift link looks like and how it works will be of interest and appreciated.

Chili -- I've seen the coat hanger version! For those of you that haven't: The Firearm Blog

While pretty much every LEO I know/worked with, etc are legit "gun guys", there are some people in the larger cities, especially in upper management, that are definitely anti-2A.
Are you at all concerned that by demonstrating 3d printed Links, that it could make some more likely to turn against ARs etc in Civilian hands, because (in their minds) "What if a Bad Guy gets a printer and makes one of those and drops it in his AR and goes on a shooting rampage?"

 

[sniperdoc]

I have tried them in a RR posty and they only lasted 3 or 4 mags. Of course I made one from a coat hanger

Do you think the deisgn flawed, or is it substandard metal/heat treatment? (I'm referring to the Link, not the coat hanger, lol)
However, do you think a much higher grade of wire would make any difference vs coat hanger? (Yes, I know that only you 07/02s can do it, us regular joes are forbidden to do so; I'm just curious as to your thoughts on design vs material)

 

[Gaujo]

I read up on these. It seems the point is to see what you can do with the 3d printer. Obviously if you made it from metal on a CNC machine the results would be much longer wear items.

It love finding random Carnic Con videos I hadn't seen before.

 

[Concorde]

While pretty much every LEO I know/worked with, etc are legit "gun guys"

The LE/govt folks that I deal with are also. I tend to deal with either local LEOs, with FBI, with ATF, and/or other gov't folks supporting military/special forces weapons and armor development.

Are you at all concerned that by demonstrating 3d printed Links, that it could make some more likely to turn against ARs etc in Civilian hands, because (in their minds) "What if a Bad Guy gets a printer and makes one of those and drops it in his AR and goes on a shooting rampage?"

Maybe I'm naïve, but no. This risk is not limited to AR platforms... there are already plans on the Internet for conversion units for Glock pistols, for banned bump-fire stocks, and a host of other things that are illegal for non 07/02 civilians to own. If I was a bad guy, a swift-link wouldn't be my first choice for illegally converting to full-auto fire.

 

[A&S Conversions]

Intuitively I would also think "late" for the reasons you said (material wearing, etc), but as long as the forward moving bolt has the round fully seated in the chamber, I don't see how it would result in a light strike in a "late" scenario, only in an "early" scenario.

The buffer helps with bolt bounce but does not eliminate it. With the timing of my DIAS using a MGI buffer, if the timing is too late, I will get light primer strikes. If you follow the procedure in the link I gave, proper timing of the hammer is released just before the carrier hits the barrel extension. There is some movement of the carrier back and forth, but the bolt is still locked. That is part of the reason why the path of the locking pin path is different in the carrier of the CMMG rotary delayed blowback system.

I read up on these. It seems the point is to see what you can do with the 3d printer. Obviously if you made it from metal on a CNC machine the results would be much longer wear items.

It love finding random Carnic Con videos I hadn't seen before.

Look at the design of the links. Going from left to right. The far left looks very solid, except where the end goes under the rear lug. If that design was rigid like it was made from aluminum, to have the lift the rear lug of the upper to rotate. The middle design wraps around the rear lug of the upper. So I would assume that the thin area in the middle to allow the end to rotate when the carrier hits it which will release the disconnector. I would think that the one on right must be made with very soft material to get the disconnector to move from the carrier impact.

Scott

 

[Concorde]

The one on the right is made from the same 3D printer plastic as the others, but the area that fits around the pin lug is looser so the whole thing can rotate slightly so the front pushes down on the disconnector.

 

[A&S Conversions]

It would seem to me that if the center one was made of anodized aluminum and a band of spring steel connecting the two halves would last a while. Maybe adding a urithain bumper where the carrier contacts. Or possibly a tool steel bumper. I am not sure which would be better or whether it would be worth while.

Of course if you were going to make such a device from metal you could design something like a DIAS with a steel trip. As the carrier comes forward, a lever takes that forward energy and pushes the back of the disconnector down which releases the hammer. Or using the same framework around the rear lug, there could be a loop around the disconnector (like a lightning link) that pulls the disconnector back as the carrier comes forward. Just a thought.

Scott