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Bore Scopes-Teslong, Depstech etc.


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Printed out a few measured scales to test the scope cameras against. Turns out I still needed to do some other pencil marking, testing; and then math. But even with the initial angular testing; I was able to estimate the same numbers calculated in the end. 

The Depstech focal distance appears to be almost exactly 6mm - 7mm or 0.25", and slightly beyond. The Field of View appears to be 45 degrees.

The Teslong focal distance is wider, giving a focus between distances of 10mm through 13mm; 0.4" - 0.51". It also has a wider FOV angle; of around 75 degrees (maybe 82 degrees?).

Should be able to attach a simple printed measuring scale to the end of the scope if one wanted those capabilities inside a bore. Might just attach it to a piece of thin stiff wire. 

IMG_6686.JPG

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That is a cool experiment there Lane.

Somehow your idea entails holding some kind of printed scale out at the focal distance... First Focal plane BoreScope.

I might try a second focal plane transparency that sticks to the mirror.  The transparency thickness could screw up clarity.  Otherwise, I guess you’d have to share the object zone with the measuring scale, held out by a wire?  That is a simple idea though to spin off of, I have some cap/resistor or diode leads that I could measure.  Maybe there in the ball park of head space thickness .003 I think.  Bet the smallest wire  is actually more than that.  Could suspend a strand of course Golden Retriever or Gopher hair across the focal plane.  Either way, cool idea, getting your printer to print so small to investigate is good practice.  After you get paid huge dollars by the Med industry, make sure you deposit .003% into BeltFeds and my account. 

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6 hours ago, Lane said:

Printed out a few measured scales to test the scope cameras against. Turns out I still needed to do some other pencil marking, testing; and then math. But even with the initial angular testing; I was able to estimate the same numbers calculated in the end. 

The Depstech focal distance appears to be almost exactly 6mm - 7mm or 0.25", and slightly beyond. The Field of View appears to be 45 degrees.

The Teslong focal distance is wider, giving a focus between distances of 10mm through 13mm; 0.4" - 0.51". It also has a wider FOV angle; of around 75 degrees (maybe 82 degrees?).

Should be able to attach a simple printed measuring scale to the end of the scope if one wanted those capabilities inside a bore. Might just attach it to a piece of thin stiff wire. 

IMG_6686.JPG

You are definitely smarter than me! Interesting experiments 👍

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Ok Lane here are two pictures of my comparisons between a good headspaced bolt closed on a case and my Sharps bolt closed on the same case.  I took movies and tried to snapshot at the same spot on the rim... couple little nicks on case neck... I’m a little off on rotation but close.  If one picture measured ..003 “ closer, I’d be in trouble.  For Reference this brass is 2.004”

 

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8CE24B29-62ED-4135-9ABF-038AFEA58C4B.png

 

Edited by DustBuster
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Brand new Wilson Combat 260 Rem, it wasn't $200 on sale.

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Brand new BSF 6.5 Grendel barrel at over $600 msrp.

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I think the WC has had a bit of hand lapping as well as just a smoother all around look.

 

 

Edited by jtallen83
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3 minutes ago, Lonewolf McQuade said:

Tree rats build a nest in there?

A good thing, fibers left from the lapping process, gonna be a much easier break in cleaning for the Wilson. For over $600 you would think BSF could smooth up those edges a bit.

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17 hours ago, DustBuster said:

Ok Lane here are two pictures of my comparisons between a good headspaced bolt closed on a case and my Sharps bolt closed on the same case.  I took movies and tried to snapshot at the same spot on the rim... couple little nicks on case neck... I’m a little off on rotation but close.  If one picture measured ..003 “ closer, I’d be in trouble.  For Reference this brass is 2.004”

I don't think you can see a difference in headspace from that vantage point. I was planning to measure the max neck length I could cram in some 300 Blackout builds though; and that would be done with pictures like those you took (and ideally a measuring scale). 

Someone else is welcome to chime in on this. But headspace is measured between the bolt face and the datum line on the shoulder of the cartridge. Even if you ended up with a bolt that doesn't close on the cartridge; the borescope view should be the same, as the cartridge is jammed up against the shoulder inside the chamber already... So that distance from the tip of the neck to the ridge in the chamber is an allowance for longer case neck. Since they stretch over time. I'm guessing based on that picture that you could probably go a hair over max length (assuming what's inside is trimmed to min length already). Even with a headspace gauge in the chamber; I don't think you can see anything of interest with the borescope. 

This is a pretty garbage picture of a measuring scale attached to the scope mirror. Each dot is 10 mil on center, and the rows are offset by 5 mil. Unfortunately I had to turn down the scope illumination quite a bit to see the dots though.

Since it's made on a laser, I can make the dots darker, or punch all the way through; or maybe just use a different material. Kapton tape might work if it's not too reflective. I could try the laser printer again, but I wasn't fully sold on the quality of tiny printing when running yesterdays tests. I'll post back when I have a more functional setup. 

Photo on 7-18-21 at 5.49 AM.jpg

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