I have always wondered if I would like that auto adjust brightness myself - almost bought a Fastfire two or three times but held off. I put a TRS-25 on my son's .22 and he loves to shoot with it now; he even adjusts the brightness to suit the climate.

 

I've had a TRS-25 for 2 years now on my FAL and I love it. Cowitnesses fine, visible on dimmer settings, hasn't changed POI v POA since I initially sighted it in. Good stuff.

But... I just got a Primary Arms 2moa dot that is almost a clone of the TRS-25, just a finer dot. Initial impression is the only difference is brightness knob location (side vs. top) and the blob that holds the light isn't as visible on the PA dot. And of course, the smaller dot (2 v 3 MOA).

Will actually get some range time soon and do a proper review/comparison. I've got it mounted on my Ruger Mk II but I'll be wanting to swap the 2 around so I use them both on a rifle and both on a pistol. We'll see where they end up living afterwards...

 

Thanks for the feedback, catbird!

I've been contemplating putting a TRS-25 back on my Single Six or getting something like the Fastfire. I wanted to save bulk and weight, but the TRS-25 I have on another gun is still working great. And it's bright, too.

So, I think you have sold me on just getting another TRS-25. That'll save me a bunch of money, too.

 

The newer Fastfire III(3) has some significant improvements over the Fastfire II(2). One is that in addition to the auto brightness, it has three manual levels to choose from. While I find the auto brightness on the 3 to usually choose an appropriate brightness level, I still use the manual levels often and am glad they are there to choose from.

The other big difference is that the battery is removable from the top so there's no need to remove the whole sight to swap batteries.

These two features make the Fastfire III a considerably better overall sight than the Fastfire 2. I bought a 3 for a Charger build and was so impressed I bought a second one shortly after which now calls a Mossberg 500 home.