Need a suggestion for a type of plastic for a project...

[SorryOciffer]

I want to make a prototype rifle stock. The material needs to be available in matte black or dyeable to black, dimenionally stable, strong, and machinable.

Delrin, Torlon????? Any others or better suited types? The actual stock will be about 1 ft long and about 1 1/4" wide.

Also, what are some good sources/vendors for industrial plastics that have it in bulk or blocks that can be machined?

Thanks,
S.O.

 

[patprimmer]

Cadillac Plastics In Silverwater carry a large range of Semi Finished plastic sheet.

If they have Polyethylene in black, kit would be a good choice, but it cannot be dyed.

If you cannot get black, do it in nylon, which can be dyed black.

Regards

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[CoryPad]

Do you know the forces involved? Military rifles use thermosets like phenolics and epoxies that have higher strength and stiffness than most thermoplastics, and some rifles use fiber reinforcements, which increases strength and stiffness even more. You may not have an appropriate material and dimensional selection at the moment.

Regards,

Cory

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[CorBlimeyLimey]

Have you considered a composite? Say a fibreglass (chopped or in-line) outer with a foam core.
Some thermo-plastics might get too brittle in very cold weather. As for colour, black could get uncomfortably hot during mid-summer days.

Are you thinking of including a recoil pad? ... or hoping the stock material selection will take care if that?


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[SorryOciffer]

No recoil pad. Won't be needed as it is only a 223/5.56mm. Are you talking about a foam core then expoxied with an overlayment of a kevlar/fiberglass type cloth? They make remote control airplane wings with that technique.... Probably doable but slow to produce. Definately would be stong and lightweight though.....hmmmmm.

It is a military rifle so the stock wont matter if it is black.

S.O.

 

[dwightdixon]

If you are making a show and tell sample for sales use, you could use anything. If you are thinking of making a working prototype, then you need to consider how and what material the final product will be produced in. Military rifle butts are used for alot of impact, not related to shooting. This thick a part would take a long time to cool in an injection molded process. You might want to hollow out the center to reduce the cycle. Using gas assisted molding might also be an opportunity. Do you have the financial resourses to see this project to a conclusion. Military approval can take years and big $$'s in testing. You might want to look for a experienced partner in the plastics business to share expertise and finances.

 

[ornerynorsk]

A glass-filled nylon spine or skeleton over-molded with TPR or similar would be my choice of materials on this. Don't underestimate the repetitive effect of .223 recoil, unless your action and barrel combination is over 6 to 7 pounds in weight. .223 is a medium/high velocity round, generating a fast shockwave, I would consider using a metal insert as a recoil lug molded into the stock.

 

[SorryOciffer]

Appreciate the input so far from everyone. This will not be put for for a military contract, it will be a reproduction of a stock that is no longer available. I think I may have found someone who can make molds for me after I send the original out to be laser scanned and reverse engineered. Not what I was hoping for but it will meet OEM specs unlike my previous idea.....