Biggest reason? At some point it has to integrate with metal, and that joint historically becomes a problem. The first carbon fiber BMX bikes ALWAYS failed as the pipe ends where they transitioned into metal.
On the AR handguard at some point you have to have a metal nut. how you join the composite to the metal is the weak point in the system. The old carbon fiber tube handguards weighed more than a 4-rail aluminum system because of that big-ass nut.
That would actually be a great idea. Something purpose built.
If the nut has to be aluminum couldn’t the receiving threads on the rail be incorporated as a solid pieces of rod like aluminum running the whole length of the rail kind of like rebar in concrete?(like dylan said)
It would have added weight from that but the overall weight would be much lighter.
maybe I just dont know but id buy something like that, I hate heavy rails.
You made a valid point. I want to points out that carbon fiber is simply one of many many many composite materials. There are many amazing new composite materials (PlumCrazy composite lower come to mind) would be perfect for this purpose.
As for the joint issue, why not design a aluminum cup that would encapsulate one end of the composite rail, the aluminum cup would be function as a reinforced bridge between the receiver and the composite rail. It could be even design in a way that the aluminum cup simple secure the composite rail in place using nothing but pressure, friction or other means without the needs of any screw holes on the composite rail system.
Nowadays we see all rail systems are based on a simple one piece design made by a single material of Aluminum alloy. I think why not a more complex design that would utilize both Aluminum and composite materials to create a rail system that could achieve the best of both world (with the properties I mentioned in the first post).
Why does everything have to be composite or polymer (don’t say plastic!)? I don’t see what will be gained once you add a few rails, as the cost will likely be up there with all of the currently available rails now.
10–M4 Product Improvement Program (PIP) - Forward Rail Assembly Solicitation Number: W15QKN-11-R-F012
The forward rail assembly kit will seamlessly integrate with the M4/M4A1 Carbine without negatively impacting or affecting the current performance or operation of the weapon. The kit shall be compatible with current M4/M4A1 ancillary equipment with no modifications to the ancillary equipment and/or the equipments mounting brackets. This ancillary equipment includes but is not limited to approved 40mm grenade launchers, accessory shotgun systems, optics/sights, aiming/pointing devices, training devices, bayonets, slings, and rail covers. All forward rail assembly kit surfaces must conform to MIL-STD-1913
I don’t know about “everything” but I can tell you why I am interested…
first, however, a nit to pick which is that while I tend to agree that “polymer” is a fancy way of avoiding saying “plastic”, “composites” are something else entirely.
I like the idea conceptually because as hand-guards get slimmer, trimmer, and more modular, they also get closer to the barrel and thinner and therefore get hotter, faster. non-metallic materials may help in shielding the shooter’s hands from that heat.
I’m also not sure if they have to cost as much or not, or weigh as much. It really all depends on that joint I mentioned earlier.
I think a heat shield could be made pretty easily with the room we have in most current tubes.
As for cost, I don’t see the end cost to the consumer being any less than what we have now. In terms of production costs, the TRX Extreme tubes are pretty cost effective and they are ~$200. I don’t see how adding multiple materials and a more complex joint keeps it under $250. My grasp on the production end of that may not be as good though.
I’m not sure a heat shield in an existing, TRX Extreme to use your example, is going to be effective, and it’s obviously also going to increase the cost. Yes, you can bubba something in there for the price of a sheet of scrap at Home Depot, but for a production system it’s going to require a way to better affix it. Will it push it to the price of a composite system? I have no idea, but until we know what the composite systems retail at when they hit the market it’s all just conjecture. You project higher, I project lower, but it’s all just a guess.
I don’t see the downside to companies pushing the envelope of tube design. When the JP tube was competing against four-rail designs everyone thought it was stupid, and now we have Samson, Troy, and MI all producing variations on that theme.
I’d like to play with one of the tubes Lancer posted, and I’m interested to hear the answers to the questions I asked as well as cost. I have some concerns about the choice of carbon fiber as the material but applaud them for trying something different in any event.
