Amazing Engineering Breakthrough!
- Thread starter iain53
- Start date
Those sound like cavalry arms lowers. Were they one piece?
The lower is under stress only at the buffer tube extension, and at the front pivot point. I suspect these might hold up fine, but I suspect they will suffer from the same failures at the front pivot that the AR-180B experienced.
I'm skeptical, but who knows.
There has been a running thread about this lower on ARFCOM
I can see some people using this as a spare or on a .22 conversion.
I don't like the plastic FCG, I see the hammers have been getting quite a bit of wear.
I will stick with aluminum lowers. Here in the states machined from forging lowers start at $60.
I can see some people using this as a spare or on a .22 conversion.
I don't like the plastic FCG, I see the hammers have been getting quite a bit of wear.
I will stick with aluminum lowers. Here in the states machined from forging lowers start at $60.
Mystic Precision
CGN Ultra frequent flyer
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- Summerland, BC
A composite trigger group????
How the heck do you get plastic to survive the pressures of a sear/trigger under spring pressure? Are the springs plastic too?
Plastic can be a wonderful product but handling high levels of vibration/loads isn't one of its strong points - certainly no plastic that I have been able to come across.
That hammer is going to get slammed down hard.
The sear and trigger parts are going to want to tear themselves apart under spring tension.
I just don't see composite wearing well.
But there are new blends every day. I just don't see 'wears like heat treated steel' and dirt cheap in the same line.
Jerry
How the heck do you get plastic to survive the pressures of a sear/trigger under spring pressure? Are the springs plastic too?
Plastic can be a wonderful product but handling high levels of vibration/loads isn't one of its strong points - certainly no plastic that I have been able to come across.
That hammer is going to get slammed down hard.
The sear and trigger parts are going to want to tear themselves apart under spring tension.
I just don't see composite wearing well.
But there are new blends every day. I just don't see 'wears like heat treated steel' and dirt cheap in the same line.
Jerry
Is not the hammer assembly and sear on the Steyr AUG made mostly of composite polymers? How often do you read about them breaking (where they can be legally owned, of course
)?
F22_RaptoR
CGN Ultra frequent flyer
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- Edmonton, Alberta
HK has been doing the composite trigger groups int he G36/SL8 and UMP/USC for quite a while, and the G36 has an amazing service life record.
There are SOME steel components (like the strike face where the hammer hits the firing pin) but there is a scary amount of plastic in those trigger groups.
If PROPERLY engineered, there is no reason an AR15 trigger group wouldn't be able to stand up to the wear and tear, although its NOT going to be as accurate and crisp as a match trigger or anything.
Plastic in the trigger group is fine and for some components better due to the natural lubricity.
FYI the 180B used some pretty low end polymer in gun world terms which is why it failed as much as it did. The thing would probably have been fantastic if they had used a better polymer with a better filling and it likely would not have needed the steel inserts. The 180B is really a cheap gun designed to be cheaper to make then the actual 180 was.
IMHO a quality polymer lower is hot ### so long as the engineering is on point. Especially when your sitting in an ambush @ -35deg.
FYI the 180B used some pretty low end polymer in gun world terms which is why it failed as much as it did. The thing would probably have been fantastic if they had used a better polymer with a better filling and it likely would not have needed the steel inserts. The 180B is really a cheap gun designed to be cheaper to make then the actual 180 was.
IMHO a quality polymer lower is hot ### so long as the engineering is on point. Especially when your sitting in an ambush @ -35deg
.I agree that plastic can be used for FCG's and lowers. I would trust the big companies like FN to have top end engineers who would use the best polymers. I just don't have that trust with little companies especially when I have seen the wear the Plum crazy hammers get. Novelty is all I see with this one.
Meh so change the hammer out. Everything starts small. There's nothing more complex about polymers then there is with metals. I would bet that if the company is decently run they will work out all the bugs whatever they may be. Personally I think its a great idea.
Anyone know the weight savings on this lower over aluminum?
F22_RaptoR
CGN Ultra frequent flyer
- Location
- Edmonton, Alberta
I can tell you that a fully loaded (as in - including trigger parts) UMP trigger group is 329 grams or just a hair over 11.5 Oz. That's including the epoxy block installed to block the UMP sear, which would make up for the smaller magazine well.
The UMP lower is pretty similar dimension-wise compared to an Ar15 lower+grip, save for the mag well size on it.
Aluminum is more dependent on the heat treatment process (T6 which is the most common) for strength. From what I've read, 6061 T6 gets 80% of its strength from the T6 heat treatment process!
So as long as the metal GRADE was the same, theoretically you could get very close to billet or forged aluminum.
The PROBLEM with aluminum is that in order to cast it, it requires silicone added to make it flow easier, which also weakens Aluminum alloys... With pressure behind it (aka as what MIM would use, a big hydraulic ram to inject the aluminum) the 6061 may be able to be injected, as long as its not too complicated a shape. Aluminum also cools very quickly, which is why it is harder to use it with injection molding type processes.
This could be where the "engineering breakthrough" is, or it could just be my imagination!
Its not the weight of the trigger group I'm wondering about its the lower itself. Generally with a glass/carbon fiber filled polymer (ala G36) the weight savings is around 30% IIRC. I'm just curious what the actual numbers are with the poly lower.
6061-t6 is certainly softer then 7075-t6, In some cases the performance difference is quite significant. Also aluminum tends to flow under pressure (lots of pressure of course) I wonder what would happen if you made some sort of extreme pressure mold? That would be cool if you could just use extreme pressure to make a part...
6061-t6 is certainly softer then 7075-t6, In some cases the performance difference is quite significant. Also aluminum tends to flow under pressure (lots of pressure of course) I wonder what would happen if you made some sort of extreme pressure mold? That would be cool if you could just use extreme pressure to make a part...
