QBZ-191 service rifle family

Aniah

Aniah

Senior Member
Registered Member
Cabbage said:
Dual oblique extractor springs – Patent number CN210533167U – Applied 2019-09-30
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This patent states that on traditional AR15 designs, the single extractor spring placed perpendicular to the bolt has a few disadvantages. First, it’s length is limited by the fact that there is a firing pin channel right beneath. This limit in length limits the force that this spring can generate. Second, the traditional AR extractor spring only puts tension on the extractor in the radial direction (i.e., perpendicular to the axis of the bolt). This means that the extractor still has “slop” in the axial direction, where it is allowed to slide back and forth along the length of the bolt a miniscule amount due to the tolerances between parts. This leads to inconsistent ejection. However, the patent also recognizes the benefit of AR extractor designs in that it allows the bolt head to be very small in diameter, leading to a more compact weapon, as opposed to AK extractors that require a large bolt head.
View attachment 81333
Below are the diagrams of the dual oblique extractor springs proposed in the patent:
View attachment 81334
The benefits stated in the patent are:
  • Two extractor springs provide a stronger clamping force, leading to better engagement of the extractor on the cartridge rim.
  • They don’t interfere with the firing pin channel, so they can be much longer
  • The oblique orientation of the extractor springs put forces on the extractor in both the radial and axial direction, effectively eliminating all slop, leading to more consistent ejection.
Additional information that can be inferred from this patent: The bolt head is AR-style, but with only 4 locking lugs. The lengths of the locking lugs (in the axial direction) are not uniform, for unknown reasons. There is also no plunger ejector, so the ejector is fixed. This conclusion can also be supported by the fact that there is a visible slot on the bolt & bolt carrier in the diagram below, taken from one of the other patents posted earlier in this thread (patent CN111426234A):
View attachment 81335
The usual disclaimer applies: these are only patent drawings so there are no guarantees that these features are applied to the actual guns identically to how they’re drawn here. However I am more sure about some features than others. The 4-lug bolt looks pretty reasonable, since the orientation of the top bolt lug matches what can be seen in the following screenshot:
View attachment 81336
The fixed ejector is also a fair assumption, due to the ejection pattern and what looks like two rivets on the left side to mount a fixed ejector to the upper:
View attachment 81337
Currently I don’t think there is any media that confirms the implementation of the dual oblique ejector springs.
Click to expand...
I just had an epiphany but if the AR-15 had this kind of bolt, wouldn't that mean it no longer needs the forward assist since this would solve the problem with the bolt not being fully chambered? Or I might just be completely wrong here since I had this idea literally pop up in my dreams.
 
C

Cabbage

Just Hatched
Registered Member
Aniah said:
I just had an epiphany but if the AR-15 had this kind of bolt, wouldn't that mean it no longer needs the forward assist since this would solve the problem with the bolt not being fully chambered? Or I might just be completely wrong here since I had this idea literally pop up in my dreams.
Click to expand...
I'm not entirely sure, but I believe if an AR is clean enough, the only reason the bolt would not fully chamber is when you ride the charging handle forward, and the BCG does not have enough momentum to snap the extractor over the case head in the chamber. This can happen on any weapon with a push feed bolt as well, not just AR15s. The added strength of the extractor springs in the 191 will increase the likelihood of this occurring, but then again, one is supposed to release the charging handle, not ride it forward. Or are you referencing another feature of the QBZ bolt that I'm not thinking of?
 
O

ohan_qwe

Junior Member
Aniah said:
I just had an epiphany but if the AR-15 had this kind of bolt, wouldn't that mean it no longer needs the forward assist since this would solve the problem with the bolt not being fully chambered? Or I might just be completely wrong here since I had this idea literally pop up in my dreams.
Click to expand...
Reciprocating charging handle have its pros like not needing the forward assist but have cons in it's moving when shooting. Nothing special here it works like an AK when in comes to forward assist.
 
TerraN_EmpirE

TerraN_EmpirE

Tyrant King
Aniah said:
I just had an epiphany but if the AR-15 had this kind of bolt, wouldn't that mean it no longer needs the forward assist since this would solve the problem with the bolt not being fully chambered? Or I might just be completely wrong here since I had this idea literally pop up in my dreams.
Click to expand...
Eugene Stoner famously didn’t design the AR15’s forward assist plunger in the original design. The original AR15 lacked such and for most of the potential problems one might encounter with the AR15 many view the AR15’s Forward assist as an unnecessary if not more of a problem. It was the US Army whom required the addition of the AR15’s forward assist.
In function a forward assist can solve an issue, but only under set circumstances. In example last year a certain Young man in the United States had to defend himself from 4+ assailants with an AR15 rifle. During the series of assaults that befell him he was knocked to the ground. In that instance apparently the bolt was left partially open so when the next assailant came with a gun of his own. The Forward assist was used to close the bolt.
This same situation could have been remedied by cycling the bolt ejecting the round and clambering a new one. The latter is actually the better solution, as most cases where the bolt has failed to close are not like that that was described above. They are normally when the rifle has failed to feed or the round is out of spec. In the Vietnam era the problem happened more often as the chamber of the rifle was damaged or the gas pressure was out of spec by the US Army’s insistence of using improper ammunition powder creating bolt bounce. In the case of Bolt Bounce closing the bolt won’t help as in the bounce it probably tripped the hammer so the gun is basically a dud.
 
TerraN_EmpirE

TerraN_EmpirE

Tyrant King
Additionally by adding the AK style charging handle Norinco has traded off a proper dust cover. The AR15’s dust cover was one of the design characteristics that was inspired from the STG44 but didn’t find a place on the AK series. It helps keep debris and detritus from entering the receiver which is a major boon in reliability of the improved AR15 series. Once the Chambers and barrels were chromed and the guide rod was replaced with a buffer weight to negate the effects of Ball ammo which was the cause of the issues on the early M16.
 
B

Boneroyalx

New Member
Registered Member
Looks like the SWAT dudes's accounts deleted some of their QBZ-191 videos. Good thing i downloaded them. I'm going to speculate it's about how those videos poorly censored the serial numbers (It also might be why the most recent video is so blurred.)
 
Aniah

Aniah

Senior Member
Registered Member
Boneroyalx said:
Looks like the SWAT dudes's accounts deleted some of their QBZ-191 videos. Good thing i downloaded them. I'm going to speculate it's about how those videos poorly censored the serial numbers (It also might be why the most recent video is so blurred.)
Click to expand...
Really? I can still see them on my end.
 
RedMetalSeadramon

RedMetalSeadramon

Junior Member
Registered Member
Cabbage said:
Dual oblique extractor springs – Patent number CN210533167U – Applied 2019-09-30
Please, Log in or Register to view URLs content!


This patent states that on traditional AR15 designs, the single extractor spring placed perpendicular to the bolt has a few disadvantages. First, it’s length is limited by the fact that there is a firing pin channel right beneath. This limit in length limits the force that this spring can generate. Second, the traditional AR extractor spring only puts tension on the extractor in the radial direction (i.e., perpendicular to the axis of the bolt). This means that the extractor still has “slop” in the axial direction, where it is allowed to slide back and forth along the length of the bolt a miniscule amount due to the tolerances between parts. This leads to inconsistent ejection. However, the patent also recognizes the benefit of AR extractor designs in that it allows the bolt head to be very small in diameter, leading to a more compact weapon, as opposed to AK extractors that require a large bolt head.
View attachment 81333
Below are the diagrams of the dual oblique extractor springs proposed in the patent:
View attachment 81334
The benefits stated in the patent are:
  • Two extractor springs provide a stronger clamping force, leading to better engagement of the extractor on the cartridge rim.
  • They don’t interfere with the firing pin channel, so they can be much longer
  • The oblique orientation of the extractor springs put forces on the extractor in both the radial and axial direction, effectively eliminating all slop, leading to more consistent ejection.
Additional information that can be inferred from this patent: The bolt head is AR-style, but with only 4 locking lugs. The lengths of the locking lugs (in the axial direction) are not uniform, for unknown reasons. There is also no plunger ejector, so the ejector is fixed. This conclusion can also be supported by the fact that there is a visible slot on the bolt & bolt carrier in the diagram below, taken from one of the other patents posted earlier in this thread (patent CN111426234A):
View attachment 81335
The usual disclaimer applies: these are only patent drawings so there are no guarantees that these features are applied to the actual guns identically to
Click to expand...
Fascinating. 4 lug bolt, AR style extractor, AK positioning, fixed ejector.

Wonder why the bottom lug is larger than the other 3:

balancing purposes for the extractor?
strengthening to compensate for the ejector channel?
Something to do with the feed ramp?

not so often u get something that's quite different from the two dominant strain of bolt faces, cant think of any other than Tavor and SAR21.
 
O

ohan_qwe

Junior Member
RedMetalSeadrmon said:
Fascinating. 4 lug bolt, AR style extractor, AK positioning, fixed ejector.

Wonder why the bottom lug is larger than the other 3:

balancing purposes for the extractor?
strengthening to compensate for the ejector channel?
Something to do with the feed ramp?

not so often u get something that's quite different from the two dominant strain of bolt faces, cant think of any other than Tavor and SAR21.
Click to expand...
Maybe for feeding from dual feed magazine. AR uses 2 lugs depending on left or right.
 
Aniah

Aniah

Senior Member
Registered Member
Some really nice close-ups on the QBU 191. We got what I would believe would be the best video showing the front barrel of the DMR and the photoshoot for the QBZ thumbnail from the previous pages. Note, the videos are both in 4K but they will take some time to fully process.



 
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