Got a Burris Fastfire II fixed red dot, the same thing you are looking at
mounted to a Marlin 30-30, well it used to be

now it's just my fun gun.
Overall size looks like this to your eye
Red dot looks like this.....but bigger when you're closer to it.
Have a look around and find the crispest dot you can get, ask that question, how crisp is that red dot? It matters. The Burris is the only one I've fired so there may be better
Extremely quick acquisition of targets is what these are all about.
Notice in the down the line picture you can clearly see outside the sight. If there is any movement on your left or right side you'll see it.
Looking through a zoom scope restricts your field of view.
You can get on target super quick and track a target with 140 degree field of view.....bottom line, it's just like a video game.
Accuracy at:
50 yrds - Superb.
100 yrds - Very nice
150 yrds - Good
200 yrds - Adequate (starts to loose out as the dot becomes 1/2 the size of the target. Can get torso grouping with a very rare bull)
300+ yrds - Spray and prey (it's a fkn craps game. 50/50 of hitting the target. The point quickly becomes to just hit the target...period)
Fit and finish is superb, mounted to a weaver, slick, no problems.
Has never come loose and must have sent close to 5000 rounds through her in the year I've had it on.
Battery life is....don't know. I've never changed it and it gets used a lot. I've left it on for weeks by accident, but still it goes. I've heard they can go for years. Comes with a replacement battery as well.
It's calling card is 50-150 yrds.
Within that yardage it's unbeatable for rapid fire and ultra quick target allocation.
Hope that helps before you dole out you're hard earned cheddar

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One of the last sets