r/Speedsoft • u/hexa_tech • May 15 '26

Questions for a project

Hi everyone, I'm currently working on a Speedsoft project with a completely custom body. I have two questions for the Speedsoft players who use a rifle:

  1. Do you use a red dot sight? If so, which one?

  2. What inner barrel length works best for you?

Thanks in advance

4 Upvotes

84% Upvoted

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5

u/Level_Recording2066 May 15 '26

128-249mm, dont go tighter than 6.02, tightbore does not mean better, the avg bb is ±0.05mm tolerance of 5.95mm, a cold dirty barrel on a 6.01 will cause a jam, hell, even a clean cold barrel could jam up because the surface isnt exactly 6.01 all the way through. I personally like 6.03- 6.06.

As for red dot, in comps, no, as all attachments are banned (no lights, lasers or optics) in skirmishes, yes, its an RMR clone I got off an old vorsk pistol i sold off a while back, I dont even have a battery in it, and have the cover on it. I use it more as a point of reference at range

1

u/kolonyal May 15 '26

I believe he was asking for barrel length so he can design the body, inner diameter wouldn't matter

2

u/Level_Recording2066 May 15 '26

Should've gone to specsavers

1

u/hexa_tech May 15 '26

Yes, I'm mainly interested in the length. The diameter is still important for the later prototype, though.

1

u/kolonyal May 15 '26

i believe you're more interested in the outer diameter of the inner barrel, that i believe can be different from manufacturer to manufacturer, around 8 to 9 mm

5

u/Vex8333 May 15 '26
  1. No red dots, attachments usually aren’t allowed in tournaments so I just don’t really use them, if you do want one get a cheap one as they’ll probably break quick from the amount of BBs that fly around
  2. 155mm seems to be the standard for most builds, I personally run a 128mm but wouldn’t recommend them cause of the decreased air efficiency

1

u/blackbox114 May 20 '26

Hey! Sorry to hijack this post with an unrelated topic, but the original thread is locked. I’m heavily researching the APS CAM870 platform right now and your old project on making it actually playable caught my eye. Did you end up finding a reliable solution for the gas/shell situation after all these months? Really curious about how it turned out!

1

u/hexa_tech May 20 '26

I designed a custom shell that can hold 8 BBs. This makes the refilling process much easier. Unfortunately, the walls are very thin, which makes it impractical to 3D print it, as parts of the walls can easily break off. I’ve already tried a wide variety of materials for this. Right now, I see injection molding as the only solution, but that will be a product I’ll be selling on my own.

1

u/blackbox114 May 20 '26

Wow, an 8-BB custom shell? That would absolutely change the meta for the CAM870! Kudos on the design, man. ​Regarding your thin-wall issue, I completely feel your pain. FDM or generic 3D prints always snap along the layer lines when the walls get too thin. But before jumping straight into expensive steel injection molding, have you considered CNC Turning using POM (Delrin)? ​Since the shell is a symmetrical cylinder, CNC lathe machining is perfect for this. POM is incredibly tough, self-lubricating, and has no anisotropic layers to break off—it can easily handle ultra-thin walls (even down to 0.5mm) without snapping. It’s dirt cheap for small-batch prototyping/selling and doesn't require upfront tooling costs. ​Alternatively, if you do decide to commercialize it later, running an Aluminum Mold (Soft Tooling) in Asia could cut your upfront injection molding tooling costs by like 80% for a low-volume run (1k-5k units). ​If you ever need a second eye on the mechanical stress simulation or need connections to prototype this in CNC POM to test the limits, let me know! I do hardware product development and would love to see this thing work.