New bolt carrier material and background info-expertise needed.

[jaybirdritenour2]

I will throw my $.02 in here since I am somewhat a plastics expert. In the year and a half we spent looking and ultimately developing our plastic for our AR mags, and now our glock mags, I can tell you that we looked at everything from metal, carbon fiber, mineral, ect in reinforced plastics. Many of the high end thermo polymers can with stand extraordinary heat (for plastic anyway), and many of them once reinforced have extremely high tensile strengths (once again, for a plastic). However, once you add in all of the fibers to increase the overall tensile strength, you end up with a plastic that is pretty brittle. This is the reason we went with a non-reinforced plastic for our mags. We wanted a high level of impact resistance. That said, the bolt will have to withstand not only high heat, but extreme impacts, and do it for thousands of cycles.

In all of the plastics I have looked at and tested, I have yet to find one with more than half the tensile strength of a good steel. Also, nothing close with regards to fatigue numbers. I am not saying that a plastic can't be made to work in this application, but I seriously doubt what you would give up in performance compared to steel would equal what you will gain.

Did you guys look at carbon nanotube composites? We cant full achieve its full abilities yet but the material itself has the potential to be far stronger than any steel known to us as of now. I dont know how far we have gotten it yet. Or silica nanofiber composites? I believe they are the strongest materials known to man with the silica being the strongest and still the lightest out of the two. They can be used in reinforcement of common polymers.

[ETSGroup]

Did you guys look at carbon nanotube composites? We cant full achieve its full abilities yet but the material itself has the potential to be far stronger than any steel known to us as of now. I dont know how far we have gotten it yet. Or silica nanofiber composites? I believe they are the strongest materials known to man with the silica being the strongest and still the lightest out of the two. They can be used in reinforcement of common polymers.

Carbon nanotubes look very promising, but I feel it's a ways off from being main stream production ready. As for the polymers with reinforcement, we can surely improve their strength with stronger reinforcement materials, but there is another part to that equation...the plastic itself. The plastic molecules entangle themselves all around the reinforcement material, but you will still reach a limit in strength because it's still all held together with plastic. Now, the longer the reinforcement fibers, the more entangled everything becomes and the stronger the material is. Several years back it was long fiber, now days is very long fiber. So plastics are getting stronger and stronger, but I still don't foresee any plastic being even close in strength to steel no matter now it's reinforced.

[jaybirdritenour2]

Carbon nanotubes look very promising, but I feel it's a ways off from being main stream production ready. As for the polymers with reinforcement, we can surely improve their strength with stronger reinforcement materials, but there is another part to that equation...the plastic itself. The plastic molecules entangle themselves all around the reinforcement material, but you will still reach a limit in strength because it's still all held together with plastic. Now, the longer the reinforcement fibers, the more entangled everything becomes and the stronger the material is. Several years back it was long fiber, now days is very long fiber. So plastics are getting stronger and stronger, but I still don't foresee any plastic being even close in strength to steel no matter now it's reinforced.

Maybe even add some non nutonian fluid to the polymer. Might help in some impact damage to polymers also. So when it's dropped it becomes slightly hard. But that would probably hurt the normal ridgity. But could help tensile strength and other propreties.

[GH41]

"So plastics are getting stronger and stronger, but I still don't foresee any plastic being even close in strength to steel no matter now it's reinforced"

Many composites, FRP with CF comes to mind, are 3-4 times the strength of many steels pound for pound but I don't think the fact adds anything to this conversation. Not trying to jack this thread but... Are the aluminum carriers any quieter than the steel ones?

[rjacobs]

To the OP:

I see you are in Dallas, let me know if you get this thing going and want to test with some suppressed 300blk. I have a side business that deals about 90% with 300BLK and shoot a ton of it.