QBZ-191 service rifle family

Iron Man · Feb 7, 2025

totenchan said:
They dovetail. What do you mean "gently caress"?

What deformation issues?

They "dovetail"? Again, dovetailing is the worst of both worlds, where it does not provide rigidity for structural support and does not allow free-floating for accuracy. There is literally zero reason for the barrel and the handguard to "dovetail". Please provide a photo of them dovetailing.

totenchan said:
When you need a handguard that long, yes, the polymer may have an issue with bending. When its a short and thick piece of likely reinforced polymer secured on both ends, as it is on the other two variants, I think its fine.

Well that's your opinion, sure. Some of us here think even shorter plastic rails are not "fine"; every other military seems to think the same way. BTW, the photo I provided is clearly free-floating. So you must think the DMR barrel is free-floating but the standard service rifle is not. Do you know of another example where a rifle type switches from non-free floating barrel to free-floating barrel because its barrel length was extended for the DMR role?

totenchan · Feb 7, 2025

Iron Man said:
They "dovetail"? Again, dovetailing is the worst of both worlds, where it does not provide rigidity for structural support and does not allow free-floating for accuracy. There is literally zero reason for the barrel and the handguard to "dovetail". Please provide a photo of them dovetailing.

I am going to give you the benefit of doubt and assume you misread and are not in fact illiterate or unable to read technical drawings. The front sight post piece dovetails into the gas block, and is secured by fasteners to the polymer handguard. I will not provide pictures because you can see this very clearly from the video your previous front sight image is from, and from any number of other pictures in this thread. As for a reason, dovetailing provides plenty of rigidity for both the front sight and handguard rail to hold zero, which was what started the argument in the first place.

Iron Man said:
Well that's your opinion, sure. Some of us here think even shorter plastic rails are not "fine"; every other military seems to think the same way. BTW, the photo I provided is clearly free-floating. So you must think the DMR barrel is free-floating but the standard service rifle is not. Do you know of another example where a rifle type switches from non-free floating barrel to free-floating barrel because its barrel length was extended for the DMR role?

Where did the free floated barrel come from? Weren't we talking about handguards? Regardless, it makes perfect sense for the DMR version to have a free-floated barrel and for the standard rifle to have a standard configuration. Why are you searching for examples when a change makes perfect sense?

Iron Man · Feb 7, 2025

totenchan said:
I am going to give you the benefit of doubt and assume you misread and are not in fact illiterate or unable to read technical drawings. The front sight post piece dovetails into the gas block, and is secured by fasteners to the polymer handguard. I will not provide pictures because you can see this very clearly from the video your previous front sight image is from, and from any number of other pictures in this thread. As for a reason, dovetailing provides plenty of rigidity for both the front sight and handguard rail to hold zero, which was what started the argument in the first place.

And yet after all this time you have provided no "technical drawings" or even photographs showing anything dovetailing into anything else. Also, rigidity is NOT for the front sight or handguard rail to hold zero, but for structural support such as during use of attached bayonets. Rigidity in the form of fixating a barrel to a handguard is positively BAD for "holding zero" since any force/movement/deformation on the handguard is immediately transferred to the barrel. This is the entire point of a free-floating barrel which you seem to not understand.

totenchan said:
Where did the free floated barrel come from? Weren't we talking about handguards? Regardless, it makes perfect sense for the DMR version to have a free-floated barrel and for the standard rifle to have a standard configuration. Why are you searching for examples when a change makes perfect sense?

Again, I asked you for ANY examples where a standard service rifle was somehow NON-free-floating but was subsequently modified to free-floating when a longer barrel was used, whether as used for DMR or not.

totenchan · Feb 7, 2025

Iron Man said:
And yet after all this time you have provided no "technical drawings" or even photographs showing anything dovetailing into anything else.

Or you could look at any number of other images posted in this thread.

Iron Man said:
Also, rigidity is NOT for the front sight or handguard rail to hold zero, but for structural support such as during use of attached bayonets. Rigidity in the form of fixating a barrel to a handguard is positively BAD for "holding zero" since any force/movement/deformation on the handguard is immediately transferred to the barrel.

Keeping the rail parallel to the barrel is "bad" for holding zero?

Iron Man said:
This is the entire point of a free-floating barrel which you seem to not understand.

The free-floated barrel, which we know that the base QBZ-191 does not have? And which many military assault rifles do not have? In fact, if you're using a strict definition, no gas operated rifle has a truly free floated barrel, so why exactly do you keep bringing it up?

Iron Man said:
Again, I asked you for ANY examples where a standard service rifle was somehow NON-free-floating but was subsequently modified to free-floating when a longer barrel was used, whether as used for DMR or not.

How is that relevant? What exactly are you trying to argue?

Iron Man · Feb 7, 2025

totenchan said:
View attachment 145149
Or you could look at any number of other images posted in this thread.

Oh that's good, a terrible low res photo. The tightest tolerances are maintained even with free-floating barrels, such that even a mm of free space is considered free floating, just like in the photo I provided of the DMR QBZ-191.

totenchan said:
Keeping the rail parallel to the barrel is "bad" for holding zero?

You clearly don't understand holding zero in this context, which is that for a non-free-floating barrel any pressure on the handguard, such as resting it on a surface during firing, can be translated into a deformation of the front end of the barrel, e.g. where the front sight post is, if the post is connected to the barrel directly or attached to the handguard, or both. If the pressure is sufficient, you 100% lose your zero, with the degree of your loss of zero in proportion to how much deformation the front end of your barrel experiences. How do you not understand the point of a "free-floating barrel" at this point in the discussion?? I would have assumed you would have looked it up by now.

totenchan said:
The free-floated barrel, which we know that the base QBZ-191 does not have? And which many military assault rifles do not have? In fact, if you're using a strict definition, no gas operated rifle has a truly free floated barrel, so why exactly do you keep bringing it up?

By way of an example, have you ever heard of the SCAR-17? I own two of them myself. How many rifles do you own, BTW? This rifle is absolutely both gas-operated AND free-floating. Multiple match-grade AR designs with gas mods are also absolutely positively 100% free-floating.

totenchan said:
How is that relevant? What exactly are you trying to argue?

It's relevant because rifles are either free-floating or not free-floating from the get-go, including the ones that have longer barrel options. Unless you want to claim that the QBZ-191 is the first rifle to do this.

totenchan · Feb 7, 2025

Iron Man said:
Oh that's good, a terrible low res photo. The tightest tolerances are maintained even with free-floating barrels, such that even a mm of free space is considered free floating, just like in the photo I provided of the DMR QBZ-191.

You are free to look up better pictures. There are plenty.

Iron Man said:
You clearly don't understand holding zero in this context, which is that for a non-free-floating barrel any pressure on the handguard, such as resting it on a surface during firing, can be translated into a deformation of the front end of the barrel, e.g. where the front sight post is, if the post is connected to the barrel directly or attached to the handguard, or both. If the pressure is sufficient, you 100% lose your zero, with the degree of your loss of zero in proportion to how much deformation the front end of your barrel experiences. How do you not understand the point of a "free-floating barrel" at this point in the discussion?? I would have assumed you would have looked it up by now.

Are you actually trying to argue that allowing the polymer handguard on which the rail is mounted to flex freely is somehow superior in retaining zero in comparison to giving up the free floated barrel and trying to ensure the handguard is rigid?

Iron Man said:
By way of an example, have you ever heard of the SCAR-17? I own two of them myself. How many rifles do you own, BTW? This rifle is absolutely both gas-operated AND free-floating. Multiple match-grade AR designs with gas mods are also absolutely positively 100% free-floating.

If I bend your gas piston, does your barrel bend?

Iron Man said:
It's relevant because rifles are either free-floating or not free-floating from the get-go, including the ones that have longer barrel options. Unless you want to claim that the QBZ-191 is the first rifle to do this.

Considering the 191 changes the handguard design completely across variants, I don't see why this is so hard for you to accept.

Iron Man · Feb 7, 2025

totenchan said:
You are free to look up better pictures. There are plenty.

I've looked them up. None of them show anything touching anything.

totenchan said:
Are you actually trying to argue that allowing the polymer handguard on which the rail is mounted to flex freely is somehow superior in retaining zero in comparison to giving up the free floated barrel and trying to ensure the handguard is rigid?

You are talking like you think there is no point in having a free-floated barrel. If that is the case, what do you think militaries and competition shooters are going for when they require free-floating barrels?

totenchan said:
If I bend your gas piston, does your barrel bend?

The answer is no. You should look up the schematics of the barrel and gas assembly for further details. Here's a hint:

totenchan said:
Considering the 191 changes the handguard design completely across variants, I don't see why this is so hard for you to accept.

The point is that rifles are designed to be free-floating from the beginning, or not, i.e. the design makes a commitment to tight tolerances and machining standards meant to ensure a certain degree of accuracy, or not.

tygyg1111 · Feb 7, 2025

Realistically it's mostly flashlights and foregrips that will be attached to the front handguard; and you're not going to see fancier stuff in widespread usage in the PLA regulars.

Where it does matter, like PAP / SWAT equivalents, there are aftermarket rail systems that were designed for running additional accessories.

Saru · Feb 7, 2025

Wrought said:
Small arms are of marginal importance to any kind of serious conflict. I'm fine with them cutting corners here so long as they don't skimp on high-end platforms; having the latest and greatest rocket artillery matters a lot more than the latest and greatest assault rifle.

They could've just stayed on the Type 56 if they needed to.

The whole point is to make Rifles more lightweight, Modular and Cheap. Armies sorted to Polymer because it was less resource intense while attaining the effectivity of per day a Firearm fully made out of Metal and Wood yet it proved that it was superior being able to absorb recoil more effectively, more resistant to rough factors while remaining more light weight.

People don't realize how much more expensive older guns were to make than your typical polymer gun. That doesn't stop them from making them overpriced in the civilian or foreign market.

Mostly metal or Fully metal doesn't mean good, Sure it's more Durable and Solid but not worth over the mentioned factors.

While the Type 56 was great and all It is not reliable long term use, and it's parts isn't gonna be cheap to replace either.

totenchan · Feb 7, 2025

Iron Man said:
I've looked them up. None of them show anything touching anything.

If the pictures available aren't enough to convince you, clearly nothing short of getting your physical hands on the rifle will.

Iron Man said:
You are talking like you think there is no point in having a free-floated barrel. If that is the case, what do you think militaries and competition shooters are going for when they require free-floating barrels?r not.

I think there is no point in having a free floated barrel when you have a flexible polymer handguard that has a rail and the alternative is letting that rail flex freely. I think having a metal handguard that has minimal contact with the barrel would be preferable purely for performance, but there were clearly other considerations.

Iron Man said:
The answer is no. You should look up the schematics of the barrel and gas assembly for further details. Here's a hint:

View attachment 145162

Pressure on the piston would put pressure on the barrel. A "true" free floated barrel has nothing on the barrel that contacts any other part of the rifle, but no one actually uses the term like that, hence why I said "strict" definition.

Iron Man said:
The point is that rifles are designed to be free-floating from the beginning, or not, i.e. the design makes a commitment to tight tolerances and machining standards meant to ensure a certain degree of accuracy, or not.

If they wanted that degree of accuracy out of the base QBZ-191, they would have used a metal handguard.

QBZ-191 service rifle family

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