DIY close range focus dry fire tool question

[kayak-man]

Hey everyone,

I’m thinking of making one of those aperture’s that you put on the end of the scope to be able to focus at extremely close ranges inside for dry fire practice, like a DFAT or IOTA. Is there a reason why I can’t just buy a cheap scope cap and drill a hole in the center?

I’m asking because every tutorial I’ve seen, people use a different price of plastic that finds inside the scope, so I’m wondering if I’m missing something…

 

[Varminterror]

Hey everyone,

I’m thinking of making one of those aperture’s that you put on the end of the scope to be able to focus at extremely close ranges inside for dry fire practice, like a DFAT or IOTA. Is there a reason why I can’t just buy a cheap scope cap and drill a hole in the center?

I’m asking because every tutorial I’ve seen, people use a different price of plastic that finds inside the scope, so I’m wondering if I’m missing something…

I made a few of my own before I bought my first DFAT. Mine worked, but I wanted to understand why the DFAT and IOTA include a lens in their construction. After getting the DFAT, I can say, the light transmission on the DFAT is better than my kydex DIY versions. Their aperture plate is also thicker than what I had used - knowing what I know about the physics of light and photography, I'm not 100% certain that has any influence, but it seems like there would be a reason to use such thick material when something thinner would do the job.

The DFAT's and IOTA's are relatively cheap. Not as cheap as a sheet of Kydex or a scope cap, but they're cheap. Either way, regular dry fire practice is sufficiently RIGHT to overwhelm the slight difference in performance between the bought version and the homemade.

 

[kayak-man]

I ended up just buying the DFAT from Rifles Only. They had outstanding customer service, and even called me before shipping because I had accidentally ordered two of the same adapter rings to make sure I wasn’t buying an extra I didn’t want.