Thread: Machining Needed - UHMWPE Polymer Stock / Chassis

Hey Guys,

I am a little tired of waiting for the Howa Mini EXCL Lite Chassis to arrive.

Constant delays on arrival in NZ and lack of these being advertised in the US makes me question if they are even in production yet.

Soo, I am thinking I might start measuring up a Howa Mini and throw together a design using CAD.

My question is, if I supply CAD files and a Block of UHMWPE Polymer, can anyone here help with the machining etc?

Paid of course!

Doesn't have to be UHMWPE, however my understanding is, this is light weight, strong and rigid, so should do the job on a low recoiling rifle such as the Howa Mini.

Might aswell make it out of aluminium, machining cost would be much the same.


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@MSL I suspected as much! But main difference is price of the aluminium.

Have you priced up the uhmwpe?


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@MSL I have not, I was under the (possibly wrong) impression that its around 1/4 the price if Alum.

Happy to come up with a design, if price isnt drastic, Alum would be the preference.

End result, I want the lightest weight option.

You wont find much that is worse than uhmwpe for thermal expansion either. I wonder how a composite/sheet metal design would go

@Chilli_Dog, bugger! Maybe I will just bite the bullet, and go with Allum. @MSL was on the right path.
Have just picked up my new 6.5G Barrelled Action, so will start measuring and designing.

Not sure what material you are thinking of, but unfilled UHMWPE is 1/3rd the density of aluminium. I still wouldn't make a stock out of it for preference.

hey mate. i have a cnc mill. but my work area is pretty small. 395mmx245mm. pm me if ya like

UHMWPE is great for many thing's but I wouldn't build a stock from it myself....a magazine maybe but not a structural componant that must retain dimensional stability threw pretty extreame temperatures.
Also soft and floppy.

Originally Posted by mimms2

All the delrins (MWPEs) are pretty cunty to machine.

I always thought Delrin was supposed to be pretty good to machine? (can't recall doing a piece offhand). UHMWPE - especially filled - can certainly have it's challenges.

I don't think Delrin is actually a MWPE, or any kind of polyethylene for that matter.

There are already plenty of ali chassis around for the howa, and most are pretty heavy.

I got sick of being dicked around re the delivery date of a stock I paid for last June, kinda glad I went and got my money back now.

I really wish we could get carbon stocks for the howa here