Personal Design Project

[SqueakH]

I am working on a design for a bolt carrier in a semi-automatic rifle. I want to make a prototype and put it through extensive testing and if I see improvement over standard design then I would like to start producing it as a "drop-in" carrier replacement kit.

The bolt carrier in mind tends to torque during operation causing wear. My design modify the bolt carrier slightly to allow a polymer sleeve to be installed on it reducing wear in area where the carrier tends to drag during operation. My question is what type of polymer would be recommend for this purpose and how can I get a small quantity for the prototyping phase and then large quantities for production? Due to the high cost of injection molding I plan on milling the parts.

Keep in mind the polymer must be able to withstand tens of thousands of cycles in the firearm at the very least.

Thank you to anyone who can assist me in this endeavor.

 

[patprimmer]

Do you want to give us a slight clue as to maximum temperatures, surface speed of the bolt against the wearing surface, nature and finish of the surface and load pressure between the bolt and wear surface.

Is hardened polished steel currently failing?

Regards
Pat
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[SqueakH]

Sorry for the delayed response. It is a piston system so the hot gasses are not dumped into the chamber keeping the bolt carrier cool to the touch. Max speed would be about 7-9 mph. The wearing surface is the buffer tube which is anodized aluminum.

 

[ornerynorsk]

MPH ?????

Is it the bolt carrier wearing out the inside of the buffer tube? Perhaps on an "AR" series rifle?

Personally, I would not expect to see any improvement in service life by attempting to polymer coat the bolt carrier. Where you might see a marked reduction of wear is to try improving the surface finish of the bolt carrier, and perhaps even doing a carbonitride or titanium nitride of its surface, and doing a substantially thick hardcoat anodize with teflon fill of the ID of the buffer tube.

Running dry vs the "slightest" amount of lubrication will make a tremendous difference, as well.

Just my 2 cents. I have never tried the above but that would be my benchmark to start from.

Good luck on the project.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[SqueakH]

Thanks.