Scope vs Red Dot vs Iron Sights - Expected Accuracy

[Charlie98]

Later purchased a red dot sight (my first) and found that aiming was easier but my groups remained pretty much the same as before.

From my experience, iron sights and red dots have about the same aiming error on the target, as most dots and front sights are about the same angular width

That's pretty much my spin on it, based on my own experience... comparing apples to apples. I built an AR as my 'DMR' rifle, it has a 1-8x scope on it... I can shoot rings around my other iron or red dot rifles with it. But that would not be a fair comparison, because it was a purpose-built rifle with premium components, shooting good handloads with match, or better quality bullets.

Observations:

1) I had a DPMS 16" carbine that shot pretty well off-hand, but really started to throw shots when rested, or even slung up. Cuprit: The barrel nut was hand tight from the factory. It now shoots as well as my other 16" carbines.

2) I do not expect anything better than 2 MOA accuracy from generic M193 or M855 ammo, or even my handloads with cheapo 55grn FMJ bullets. I get better accuracy with better quality bullets, which, right now, are 62grn Hornady BTHP or FMJ bullets. I consider any NATO-spec 5.56mm ammos to be MOBC ammos... or Minute of Body Cavity. In my opinion, that's what they are designed for; expecting them to shoot like Black Hills or FGMM is foolhardy. Garbage in, garbage out... if you want better accuracy, start with better ammos.

3) My Colt H-bar, with it's 1:7 twist barrel, pretty much hates everything 55grn that I've run through it. It is an anomaly, because my other 1:7" rifles shoot 55grn stuff well enough.

There are a number of facets to accurate shooting with an AR... like someone else mentioned, better sights (red dot or scope) don't help accuracy if there is a weaker link in the chain... improperly assembled rifle, poor quality ammunition, poor quality barrel... or any version or combination of those factors.

 

[CraigC]

I get terribly amused when folks try to defend iron sights (against magnifying riflescopes) by telling a person they must match their target to the distance at which they're shooting. I'm sure this is due to how I approach a rifle, or any firearm. I may, occasionally, shoot my rifles for groups on paper, but that is not why I have any of my rifles. Every one of them is a 'working' gun, or at most an NRL-type (PRS-type) play toy, too. So, the entire concept of asking an elk (or javelina or bear or squirrel or...) I may see out there to please move along and quickly send in another of a different size, that's better suited to how far away from me he is, is extremely amusing!

Methinks you totally lost the context of those comments.

 

[MZ5]

Maybe so. Or, maybe it's just that my mind goes in 18 directions at once, and makes connections all over the place that were not intended. My comments are in good fun, not attacking in nature. I had an actual grin on my face while I typed all that out.
(-:

 

[lysanderxiii]

Way back in the 1950s, Aberdeen proving Ground did a test to measure aiming error with various sight types, from the old fashion "bead-and-buckhorn" open sights to an 8X telescope and everything in between. The test basically took an image of the sight picture when the "shooter" decided the sights were on target. The shooters were all High-Power and Small-Bore Master or Expert rated. Some of the things they noted:

1. Learning. They found that while the least experience individuals had errors 2.6 times worse that the most experienced individuals, after three days of testing (dozens of ten-round "groups" per day), they had reduced the difference by a third.

2. Illumination. Iron sights are illumination dependent, optical sights, less so. Similarly, contrast between the target and background makes a bigger difference with iron sights than with magnifying optics.

3. Design. The most effective type and size of iron sights are dependent on the type of target. Aperture front sights are great for bullseye targets, but not great for game, and can be equally bad for bullseyes targets if the aperture is to big or small. Similarly, optical reticle type must be selected to be visible over a wide range of lighting conditions and not cover excessive amounts of the target.

4. Non-magnifying optics offer only a slight aiming error advantage over an optimized iron sight set-up.

5. Fatigue. Iron sights, especially under poor lighting conditions, cause more fatigue than optical sights.

 

[Snidely70431]

If you are only shooting paper targets in competition, then it may be important whether your firearm shoots 1 MOA or 2 MOA, but IRL even a 5 MOA firearm is more than adequate at realistic ranges.

Maj EGB Reynolds states the accuracy standard for the No. 4 Mk I was the same as the No. 1 rifle at 100 feet (five rounds had to be contained in a rectangle 1 inch wide by 1.5 inches high). That translates to 4.5 inches at 100 yards (4.5 MOA).
Mauser 98 accuracy acceptance standard was 4.6 MOA with 5 out of 5 rounds at 100 meters (328 feet). So it seems the acceptance standards for both rifles were near identical.May 7, 2019