Best dot size for a pistol mounted Red Dot?

Don't think so much about seeing the dot super clearly as seeing the target clearly. It's different than the iron sights most of us grew up with.

The smaller dot is more precise but you will see every tremor and wobble in your technique. When you pick up your pistol and it is not quite aligned with your eye, the red dot will let you know as you won't see it!

As far as dot size, what are you accuracy expectation or aspirations? If you want to shoot the wings off a fly, the smaller dot will be more conducive to that. If you want to keep you shoots within a desert or dinner plate size target at reasonable ranges, the larger dot might be easier to learn and quicker to acquire.

Whatever you pick, expect to have to practice and relearn how to shoot. It's not like going back to zero as the fundamentals of trigger control, stance, ... are the same but it's enough different that there is a learning curve.

Hang in there, put in the time and you will probably emerge a better and happier shooter. I say happier because your range visits will not feel so much like an eye test.

Best of luck. Let us know what you decide to do.

Size matters

It is not just the red dot size that matters, it is how does the size integrates with your setup and goals. How do you want to sight your gun? I sight mine to zero the red dot at a range that will result in a maximum POI error of +1.5 inches at ranges farther than the zero range. That, of course, is a function of your chosen ammo and your gun's performance and the height of the red dot above the bore. In my guns, that sets the zero at about 40 yds, but my Q5 is zeroed at 51 yds, but I do not use my Q5 for home defense. So, my home defense guns, zeroed at about 40 will result in a second zero (bullet on the way down) at about 60 yds. That is all based on the geometry of my Leupold DeltaPoint Pro optics, that I chose for field of view and the sleep mode.

Anything inside the zero range is going to require a holdover, and you can use the dot size to give you important hints. In my defense guns, with 2.5 MOA dots, the dot is essentially centered for ranges down to a little less than 30 yds. Inside of that, you aim high. How much? Never more that the height of your dot above the bore. The result for my Q4 TAC is that I can shoot a centered dot from zero to about 70 yds with no more than a 1.3 inch vertical error. That is better than I can shoot, so the red dot is not an error contributor to an extent that I need to think about it.

For a pistol, I believe quick acquisition is important. I use the Delta pro 7.5 triangle for my Q5 because I always calculate my holdoffs for a fixed geometry tactical range. But, as I said, I use the 2.5 dot on my defense guns. The dot size really becomes important when you are looking for aiming aids at longer ranges. In my case, I have configured my AR-15 with a 4 MOA dot. Why? Because a 100 yd zero occurs at the top of the dot. The center of the dot is good at 200 yds and the bottom of the dot is dead on at 300 yds.

The final consideration is your ability. I can shoot my Q5 at slightly better than 4 MOA standing, so I am not going to be better with my Q4 or P99 or CZ standing, which is the shooting position I assume will apply for all defense scenarios. So if I was interested ONLY in self defense, I could use a 4 MOA dot to cover the best I can shoot.

So there it is. I use the 2.5 MOA dot because I prioritized other aspects of a red dot above red dot size. I believe that if Leupold offered a 4 MOA Delta Pro, I would be a very happy camper.

kenkg said:

It is not just the red dot size that matters, it is how does the size integrates with your setup and goals. How do you want to sight your gun? I sight mine to zero the red dot at a range that will result in a maximum POI error of +1.5 inches at ranges farther than the zero range. That, of course, is a function of your chosen ammo and your gun's performance and the height of the red dot above the bore. In my guns, that sets the zero at about 40 yds, but my Q5 is zeroed at 51 yds, but I do not use my Q5 for home defense. So, my home defense guns, zeroed at about 40 will result in a second zero (bullet on the way down) at about 60 yds. That is all based on the geometry of my Leupold DeltaPoint Pro optics, that I chose for field of view and the sleep mode.

Anything inside the zero range is going to require a holdover, and you can use the dot size to give you important hints. In my defense guns, with 2.5 MOA dots, the dot is essentially centered for ranges down to a little less than 30 yds. Inside of that, you aim high. How much? Never more that the height of your dot above the bore. The result for my Q4 TAC is that I can shoot a centered dot from zero to about 70 yds with no more than a 1.3 inch vertical error. That is better than I can shoot, so the red dot is not an error contributor to an extent that I need to think about it.

For a pistol, I believe quick acquisition is important. I use the Delta pro 7.5 triangle for my Q5 because I always calculate my holdoffs for a fixed geometry tactical range. But, as I said, I use the 2.5 dot on my defense guns. The dot size really becomes important when you are looking for aiming aids at longer ranges. In my case, I have configured my AR-15 with a 4 MOA dot. Why? Because a 100 yd zero occurs at the top of the dot. The center of the dot is good at 200 yds and the bottom of the dot is dead on at 300 yds.

The final consideration is your ability. I can shoot my Q5 at slightly better than 4 MOA standing, so I am not going to be better with my Q4 or P99 or CZ standing, which is the shooting position I assume will apply for all defense scenarios. So if I was interested ONLY in self defense, I could use a 4 MOA dot to cover the best I can shoot.

So there it is. I use the 2.5 MOA dot because I prioritized other aspects of a red dot above red dot size. I believe that if Leupold offered a 4 MOA Delta Pro, I would be a very happy camper.

Click to expand...

All Good stuff!

I have been shooting red dots for awhile. People say "Get a bigger dot for easy dot pick-up " Well, I find that the size of the dot for recognition simply doesn't matter. The dot is either there... or it isn't. A shiny red orb will be there if you are pointed right.

A smaller dot is Much better if you have an astigmatism. Those of us dealing with astigmatisms get to view all sorts of fun shapes. It can be managed, but you have to choose a portion of the blob to use.

As for sight in range, I use 10 yards. My dot rests .9 inches above my barrel. With a 10 yard zero, I am within an inch all the way out to past 50 yards. A 3 MOA dot covers 3 inches of target surface at 100 yards. At 50 yards, 1 1/2 inches. At 10 yards, 1/3 of an inch. Sighted this way, from 7 yards, all the way out to beyond 50 yards, the bullet will land somewhere inside your dot picture.

The key here is knowing how big your dot will appear on your target at the distance that you are shooting. Then, knowing where you have sighted in, you can use the top/middle/bottom of the dot for aiming purposes if you are looking for precision. All easier with a smaller dot, and again, for acquisition, my contention is that dot size doesn't matter.

For reference, I use RMR's, Sig Romeo's, Vortex Vipers and Venom.

Just my 2 cents.

Previous two post are excellent.

But to just add a few more thoughts. Most shooters probably already know, but for those that don't......

All bullets/projectiles fly an arc....whether its a battle ship firing 16" shells or a measly little ole 22. One has to understand and 'know' the ballistic profile of the round they're shooting.

The following charts are based on a 9mm using Speer GDHP 124 gr ammo and a sighting line 1" above the bore. Four charts, depicting a 'zero' at 16, 50, 75 and 100 yards.

Don't let the exaggerated arcs throw you....look at the left side for the height (in inches) and the bottom for distance (in yards).

First off, 16 yard zero.
Bullet comes out and is climbing...intersecting line of sight (aim) at 16 yards. Bullet continues to climb (yes, its flying an arc) reaching a peak of about 1/2" high at 32 yards, then starts back down...again intersecting line of sight at about 46 yards and is about 6.5" low at 100 yards.


Next, a zero at 50 yards.

Wow, the 50 yard 'zero' looks so much like the 16.


75 yard zero.


And 100 yard zero. Only 3.5" high at peak arc.


What does all that mean? Zero your pistol at any distance you like.....aim for center mass at your typical SD/HD ranges (50 feet or less) and if you did your part...meaning didn't flinch....you'll get a hit.

As for dot size.....for HD or SD...IMHO, how cares....it'll happen so fast you surely won't care.