Material Matters (Machining Internals)

[Sheepdog]

I would like input on the following topics for anyone who has experience and expertise, and would like to chime in. This mostly pertains to different materials used for machining internals.

• What are the most common materials and grades of material used for making internals by the major manufacturers?
• Does anyone have experience using different materials?
• What materials would be recommend for making parts. (303/316 Stainless, Brass, Mild Steel, Titanium Etc.)

Would love to hear what you guys think.

Thanks

[jokers]

Coolness factor, use Titanium. "I have a titanium autococker cocking rod!" Sounds so much cooler then "I have a steel , brass, or other material autococker cocking rod."

[Sheepdog]

Thanks for the input Jokers. Coolness factor is def a part of the process. I am considering Ti although i is a very difficult material to work with.

[Ecapnation]

Generally speaking...

6061-T651 aluminum
316 or 18-8 stainless
Brass 360 alloy
And....
delrin
Nylon 6-6
or acetal copolymer

[Sheepdog]

About what i expected. Pretty run of the mill stuff. Any thoughts on 416 or 17-4?

[Ecapnation]

Ain't nobody in paintball with fancy alloy money

[Sheepdog]

Fair enough. 😂

[Ecapnation]

The only outlier would be the NXT shockers were made in 7075-t6 not sure if that's continued to the newer ones but I highly doubt it.

[Sheepdog]

Wonder what the justification for the x3 price in raw material over 6061 was?

[superman]

agd used 7075 also for the ule bodies.

[flyweightnate]

I heard early shockers were 2024, thus the "wet erase marker" levels of dye permanence in the ano.

[DocsMachine]

What Ecap said, with a bit more info:

Generally speaking, you can make almost an entire marker- like a CS1- out of 6061 aluminum. That's by far the most common machined/machinable alloy, available in a wide variety of shapes and sizes, etc. If you went to a metals supplier and asked for three feet of 1" round- you'd get 6061. If you wanted some other alloy, they'd probably have to special order it.

That said, other alloys are occasionally used. The old '03 Shocker (the first generation after the "shoebox") was 2024, which is in some aspects stronger than 6061, but doesn't take anodizing as well. The original WGP Autocockers used a different alloy for the vertical ASAs, probably also due to strength concerns. (And probably also 2024.)

In the very early days of 3rd-party 'Cocker bodies, one of the first ones available- Air America, maybe?- made theirs out of 7075, which was also a stronger alloy than 6061.

In other materials, most of the stainless you're going to find is 303, since that's considerably easier to machine than 304 or 316. A lot of the rod you'll find (pump rods, cocking rods, etc.) is 304 or 316.

There'll be things like 'Cocker triggers and sears, which in the old days were some flavor or another of a common tool steel (A2, O1, etc.) which was then nickeled or chromed, and today is generally something like a 17-4 or 18-8 stainless.

Things like blowback hammers and sears could be anything from 4140/4150 to 1045 steel, usually heat-treated to the 50+ Rockwell C range.

Machined plastics will almost always be some flavor of Delrin (Ecap's 'Acetal copolymer'- Delrin is a copyrighted product name) with anything clear or translucent being an acrylic.

And that pretty well covers it. Apart from injection-molded plastics, molded rubber/silicones, Buna-N or Polyurethane O-rings, urethane seals or bumpers, and of course things like screws, pins or clips, that's almost all you're going to see in a typical paintball gun.

Doc.

[Sheepdog]

Doc,

Thanks so much for the reply. You are indeed an unbelievable wealth of paintball knowledge.This helps tremendously. I have already made some parts for my Rainmaker project out of 6061. Machines so nicely. Going to try and take on some steel and Delrin soon. I'm sure most of what could be done, has been done. Never the less, i'm excited to build.

Thanks again.

Sheepdog

[$L!mBo]

this post should get stickied

[DocsMachine]

What it should be is vetted, expanded, corrected and then stickied.

I don't, for example, know exactly what the alloy of the old WGP VASAa were. I know it always tended to anno a different tone than the rest of the gun, but it was only an educated guess on the alloy. (2024 is generally assumed to be very close to mild steel in strength, and so I could see it being used for a stressed part like an ASA.)

I do know about the Shocker bodies, as I have a machinist industry trade magazine from back then, that covers Smart Parts at the time. I recall specifically it saying they used 2024, but I don't recall if they said why.

We can also just about guarantee that if something is brass, it's 360- that's by far the most common alloy. And moving to something else would greatly increase the per-part cost, without a significant improvement in strength or wear. (Making a "Naval Bronze" 'Cocker valve, for example, would gain you nothing but marketing-hype points. )

Doc.

[Spider!]

While 7075 is significantly stronger than 6061, I recall both AGD and PTP writing that it is hard to work with in machining and ano.

"Free machining" metals really are nice. Besides 303 SS, 360 brass, I've come across some 404 SS that is crazy easy to cut.

If you're making one part, it's hard to be picky. Only use mild steel where you can (will) take care of it (clean and lube).

[Morgenstern]

Years ago I was researching material for making aftermarket bolts and came across Ertalyte TX PET. Better dimensional stability, wear resistance, sound dampening and friction reduction than anything used in paintball. I used to have a couple rods of it I bought to experiment with but never got around to finishing anything. Seemed like great stuff, very hard and slippery compared to Delrin.

[Sheepdog]

Pretty high dollar stuff, but defiantly an option. Thanks for the input Morgenstern!

[DocsMachine]

Pretty high dollar stuff, but defiantly an option.

-That's a big part of the equation, right there.

For aluminum, 6061 is by far the most common as far as typical extruded bar stock. And as such, it enjoys 'economy of scale'- basically, because the foundries make so much of it, it's less expensive per pound than many other alloys.

Therefore, unless the part requires other or superior features (hardness, toughness, wear resistance, etc.) you go with 6061.

7075 can cost considerably more per pound, so you only want to use it where it's needed, not "just because it's better".

Which means, given that the manufacturers aren't generally going to spend money they don't have to, we can make a pretty good educated guess on most of this stuff.

Doc.

[Sheepdog]

Doc,

Fortunately I work in a shop that has some pretty wild off cut "scrap" that is up for the taking. Trust me, I'm grateful for the benefit. Learning some 7075 at the moment. Just trying to get smarter on all things especially material and its appropriate uses.

Many thanks again!

Sheepdog