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Posted: 10/10/2016 5:03:36 AM EDT
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Hi all.
I wonder if a full auto HK416 lower would be compatible with a standard AR-15 upper? Of course the full auto mode would not work, but sometimes it would be nice just to test other uppers/calibres with a lower/trigger that I like. Did my best with Google-Fu, but no positive confirmation about compability. Anybody who KNOWS for a fact? Best regards, Kai PS: Really keen to test 300BLK and 6.5 Grendel. |
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I'm unsure of compatibility, but why would swapping uppers eliminate the full-auto capability of the lower?? If the lower has an auto sear and 3rd pin, it will run full-auto regardless of the upper that is attached to it. That is unless I'm completely missing something. |
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Quoted:
I'm unsure of compatibility, but why would swapping uppers eliminate the full-auto capability of the lower?? If the lower has an auto sear and 3rd pin, it will run full-auto regardless of the upper that is attached to it. That is unless I'm completely missing something. The upper would of course have a semi auto bolt carrier. The full auto one in piston HK416 would not work in a DI gun. /K |
| Here in the United States the vast majority of AR uppers these days have full auto bolt carriers. Mil HK-416 uppers run just fine on standard M-16 lowers and while I've never tried the reverse (416 lowers have no advantages over a -16 lower) it should work as well. |
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Quoted:
I'm unsure of compatibility, but why would swapping uppers eliminate the full-auto capability of the lower?? If the lower has an auto sear and 3rd pin, it will run full-auto regardless of the upper that is attached to it. That is unless I'm completely missing something. You also need a FA bolt carrier AND an upper receiver with a cut out for the sear. Semi auto upper receivers are not common but they are out there.. |
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Quoted: You also need a FA bolt carrier AND an upper receiver with a cut out for the sear. Semi auto upper receivers are not common but they are out there.. Quoted: Quoted: I'm unsure of compatibility, but why would swapping uppers eliminate the full-auto capability of the lower?? If the lower has an auto sear and 3rd pin, it will run full-auto regardless of the upper that is attached to it. That is unless I'm completely missing something. You also need a FA bolt carrier AND an upper receiver with a cut out for the sear. Semi auto upper receivers are not common but they are out there.. |
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Quoted:
Are you speaking exclusively about the HK product? There is nothing to differentiate an AR15 - M16 upper receiver from semi auto to full auto, and I can't imagine anything different with HK either. Only the BCG would be different in either weapon. If I am incorrect please correct me, which would only reference the HK as I know for a fact with the ar -M16 platform does not. Quoted:
Quoted:
Quoted:
I'm unsure of compatibility, but why would swapping uppers eliminate the full-auto capability of the lower?? If the lower has an auto sear and 3rd pin, it will run full-auto regardless of the upper that is attached to it. That is unless I'm completely missing something. You also need a FA bolt carrier AND an upper receiver with a cut out for the sear. Semi auto upper receivers are not common but they are out there.. Actually there is a difference... in standard FA AR uppers, there is a sear relief cut just forward of the rear takedown lug (the oval cutout). While it is exceedingly rare to see an AR upper without it, they do exist. Now when discussing 416 and MR556 uppers, it tends to be more talked about BC it is absent on all the MR556 factory uppers I've seen. The relief cut just gives the sear on an M16 lower some room to move. In a semi AR the relief cut is completely unnecessary, but remains as an artifact. |
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So essentially, the HK416 lower fits a standard civilian AR upper regarding pins etc? And IF the BC is of the full auto version, then in many cases the full auto would work also?
That means that experimenting with a standard upper with different calibres would be possible with HK416 lower :D /Kai |
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Quoted: Actually there is a difference... in standard FA AR uppers, there is a sear relief cut just forward of the rear takedown lug (the oval cutout). While it is exceedingly rare to see an AR upper without it, they do exist. Now when discussing 416 and MR556 uppers, it tends to be more talked about BC it is absent on all the MR556 factory uppers I've seen. The relief cut just gives the sear on an M16 lower some room to move. In a semi AR the relief cut is completely unnecessary, but remains as an artifact. Quoted: Quoted: Quoted: Quoted: I'm unsure of compatibility, but why would swapping uppers eliminate the full-auto capability of the lower?? If the lower has an auto sear and 3rd pin, it will run full-auto regardless of the upper that is attached to it. That is unless I'm completely missing something. You also need a FA bolt carrier AND an upper receiver with a cut out for the sear. Semi auto upper receivers are not common but they are out there.. Actually there is a difference... in standard FA AR uppers, there is a sear relief cut just forward of the rear takedown lug (the oval cutout). While it is exceedingly rare to see an AR upper without it, they do exist. Now when discussing 416 and MR556 uppers, it tends to be more talked about BC it is absent on all the MR556 factory uppers I've seen. The relief cut just gives the sear on an M16 lower some room to move. In a semi AR the relief cut is completely unnecessary, but remains as an artifact. |
| Yeah, the cut out is by far the norm these days. I think the lack of the relief cut was more common by the smaller manufacturers back in the 90s? As far as more recent stuff, there are a handful, I'm not sure but I heard that maybe some of Mag Tactical's uppers didn't have it back before they folded and maybe some Anderson's? I haven't seen those for sure though. |
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Quoted:
Yeah, the cut out is by far the norm these days. I think the lack of the relief cut was more common by the smaller manufacturers back in the 90s? The only maker who ever routinely left the sear relief off their uppers was Colt, for the SP1/Sporter II rifles and some other semi models. |
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Quoted:
The only maker who ever routinely left the sear relief off their uppers was Colt, for the SP1/Sporter II rifles and some other semi models. Quoted:
Quoted:
Yeah, the cut out is by far the norm these days. I think the lack of the relief cut was more common by the smaller manufacturers back in the 90s? The only maker who ever routinely left the sear relief off their uppers was Colt, for the SP1/Sporter II rifles and some other semi models. The DPMS Lo-Pro uppers also lack the sear relief cut. |
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Quoted:
Hi all. I wonder if a full auto HK416 lower would be compatible with a standard AR-15 upper? Of course the full auto mode would not work, but sometimes it would be nice just to test other uppers/calibres with a lower/trigger that I like. Did my best with Google-Fu, but no positive confirmation about compability. Anybody who KNOWS for a fact? Best regards, Kai PS: Really keen to test 300BLK and 6.5 Grendel. For a fact...HK416 lower works perfectly in semi and full auto with standard AR15 uppers (DI). |
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