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All Springer/NP/PCP Air Gun Discussion General => Projectiles => Topic started by: Nvreloader on May 21, 2021, 03:52:33 PM

Title: Peek Rod = Pressure possible?
Post by: Nvreloader on May 21, 2021, 03:52:33 PM

Guys
I have to make some more pellet head forming dies, = round/domed and HP designs and
skirt forming adapters for various brands of pellets, in my HD sizing press etc.

I am wondering, if I could use PEEK 1/2" rod,
these adapters will be used for forming Pure lead pellets, being held inside a NOE sizing die.

Could Peek stand up to this pressure?

I have run out of steel rod, and have to wait for the shipping time to get here etc.
But I do have several short pieces of 1/2" diameter Peek stubs in the scrap drawer........... ;)

Your thoughts or suggestions................

Tia,
Don

Title: Re: Peek Rod = Pressure possible?
Post by: rsterne on May 21, 2021, 04:42:30 PM

PEEK has compressive strength of 17-18 ksi, way higher than pure lead, so I'm guessing it would work.... but I wouldn't spend a lot of time making them without testing it.... Drill a hole in some PEEK a whisker larger than a pellet, with an extractor pin in place, and tap it into place with a punch to swage it to fit the cavity, and then drive it out.... That should tell you right away if it will work.... Brass has a compressive strength of about 24 ksi.... I don't know if those values are to failure, or to a given % distortion....  ???

Bob

Title: Re: Peek Rod = Pressure possible?
Post by: Nvreloader on May 23, 2021, 02:24:44 PM

Thanks Bob

I'll be using NOE size dies,
these Peek rod punch will fit the inside bore diameter of the NOE dies,
forming a domed/round head and a tapered pin skirt that fits the inside dimensions of the pellet skirt,
and will fit my HD sizer press.

I'll build one in each caliber-22/25 to test.

Tia,
Don

Title: Re: Peek Rod = Pressure possible?
Post by: rsterne on May 24, 2021, 05:17:31 PM

Are you planning on making the head and skirt diameter the same?.... Commercial pellets always have the skirt larger, by about 0.005-0.010", depending on caliber....

Bob

Title: Re: Peek Rod = Pressure possible?
Post by: Nvreloader on May 24, 2021, 07:36:31 PM

Bob

Not at this time,
 
The NOE dies have a taper/funnel leading into the main straight sizing section,
I can see it, but I can't measure it, with the tools I have here.

I planned to set up the size dies to have the top funnel section fit the skirt taper, as close as possible,
then bump size the pellet heads to whatever diameter needed to shoot accurately in which ever rifle I am using etc,
and still have the skirts seal the bore, when finished sizing.
There is lots of adjustments for moving the pellet up or down in the press I am using

I have several NOE dies in various sizes to fit 22 and 25 cal, I need to open up the .172 dies to fit the .177 calibers,
since there is no NOE dies in this caliber.

Am attempting to find my Woods metal, so I can get a cast of the inside dimensions of the inside of the NOE dies,
then I can figure out where the taper section ends and figure the info needed for adjustments range etc.

Suggestions or Ideas and or Info will be greatly appreciated............ ;)

Thanks,
Don

Title: Re: Peek Rod = Pressure possible?
Post by: rsterne on May 25, 2021, 01:13:51 AM

I use a set of these....

(https://images-na.ssl-images-amazon.com/images/I/51nWaDdiSNL._SL1001_.jpg)

You adjust them until you just feel drag, remove and then measure with micrometers....

Bob

Title: Re: Peek Rod = Pressure possible?
Post by: Nvreloader on May 25, 2021, 09:41:50 AM

Thanks Bob

I have a set of ball mikes, but I don't have the small one to fit the .215" or smaller holes,
As I can't find it in the shop..........anywhere ::) 
I think my bench Gremlin has it hidden somewhere.

Don