MantisX Live Fire Unreliable

[D.B. Cooper]

Anyone using their Mantis device in actual live fire at the range?

I used my MantisX in live fire mode for the first time running the dot torture drill yesterday, and I was not impressed. I got a lot of "91-99%" and "good shot" and "great shot" results, but my rounds were all impacting left or low and left of the targets. (Seven yards, which is the minimum my range allows.) I shot pretty good groups, but very few of them hit the targets. I didn't do the full dot torture drill; I fired every string as though it was dot #1-basic, two-hand hold, untimed.

Has anyone else had a similar experience in live fire? Any idea of the cause? (My only thought is that I'm using the magazine adapter to mount the Mantis device, and perhaps the magazine or adapter isn't square to the bore axis.)

Lastly, is this even a concern? Should I just say "My groups are tight and consistent, my shooting is good" and move on?

 

[Shawn Dodson]

MantisX doesn't know where your bullseye is located in space, it doesn't know if your sights are aligned, and it doesn't know if you have a proper sight picture.

MantisX is just a couple of accelerometers that measure movement of the pistol immediately before and after the shot.

Apparently you aren't moving the pistol very much when you work the trigger, which is why it's reporting "good shot" and "great shot".

IMO, where your bullets are landing on the target is either a problem with your sights (the bullets don't hit where the sights are aligned) or shooter error.

 

[JohnKSa]

Yup. It sounds like your trigger technique is very good (which is all that the MantisX measures) but the sights are not properly regulated.

 

[D.B. Cooper]

IMO, where your bullets are landing on the target is either a problem with your sights (the bullets don't hit where the sights are aligned) or shooter error.

I'm inclined to believe it's shooter error, but I'm having trouble diagnosing it.

Yup. It sounds like your trigger technique is very good (which is all that the MantisX measures) but the sights are not properly regulated.

I dunno. Factory stock Beretta 92. If I put it on a bench with a sand bag under the barrel and under the grip, it shoots dead on. I don't think those sights are even adjustable, are they? Blazer brass ammo but it's from different lots as I've been accumulating it for a while.

 

[JohnKSa]

The MantisX is telling you that you are not moving the gun around while pulling the trigger. That pretty much eliminates flinch/anticipation as the cause of the POA/POI mismatch.

That means either you are not aiming where you intend to or the gun is not hitting where you are aiming.

I don't often run into shooters who don't aim where they mean to aim in slow fire shooting. Sometimes if they are trying to go fast then they will forget to watch their sights, but when shooting without time pressures, people are generally very good about aiming where they want the bullet to hit.

So that suggests that the sights aren't regulated properly.

If you are saying that when benched it is shooting to point of aim, then that gets us back to the idea that you aren't aiming where you want the bullet to hit. That seems unlikely, but with the other possibilities eliminated...

 

[D.B. Cooper]

The MantisX is telling you that you are not moving the gun around while pulling the trigger. That pretty much eliminates flinch/anticipation as the cause of the POA/POI mismatch.

That means either you are not aiming where you intend to or the gun is not hitting where you are aiming.

I don't often run into shooters who don't aim where they mean to aim in slow fire shooting. Sometimes if they are trying to go fast then they will forget to watch their sights, but when shooting without time pressures, people are generally very good about aiming where they want the bullet to hit.

So that suggests that the sights aren't regulated properly.

If you are saying that when benched it is shooting to point of aim, then that gets us back to the idea that you aren't aiming where you want the bullet to hit. That seems unlikely, but with the other possibilities eliminated...

Agreed. I'm definitely aiming dead on. Sight adjustment would be the easiest solution. That would make a huge difference out past 25 yards. (At 25+ yrds, rounds start missing the left edge of a 12" steel plate; at 15 yrds, all rounds impact the left half of the 12" steel plate.) I don't have this problem with my carry gun. (Also a da/sa 9mm)

 

[JohnKSa]

The rear sight on the Beretta 92 is drift adjustable--but they can be really tight in the dovetail. You may want to find a gunsmith with the proper adjustment tool.

Shoot a careful group with a clearly defined point of aim on paper at a known distance (the longer the better) and that can be used to determine exactly how far the sight needs to be drifted.

 

[lemaymiami]

One other possibility is actually the shooter's eyes when things go south... If you haven't visited your eye doctor in a few years you might want to get them examined properly to see if there's any issues on that side of the equation. I just made a choice to upgrade my own eyecare after years of only using discount "cheapie" vision outfits. The results were surprising but at age 74 and still working on the water I hadn't noticed the changes at all...

 

[Jeff White]

Agreed. I'm definitely aiming dead on.

Maybe you aren’t. Astigmatism and other vision issues can cause you to be actually looking at the sights on an angle. One technique I’ve used to diagnose the problem in students is to use a blue gun that I filed the rear sight notch in. I have the shooter grip and aim as he normally would and I look at the alignment between the sights and the shooters eye.

You may be slightly canting the weapon to one side to get the “dead on” sight picture you see.

 

[Odd Job]

I'd let another shooter try that same setup.

 

[D.B. Cooper]

Maybe you aren’t. Astigmatism and other vision issues can cause you to be actually looking at the sights on an angle. One technique I’ve used to diagnose the problem in students is to use a blue gun that I filed the rear sight notch in. I have the shooter grip and aim as he normally would and I look at the alignment between the sights and the shooters eye.

You may be slightly canting the weapon to one side to get the “dead on” sight picture you see.

Interesting hypothesis. Another way I might try to prove that is using the laser cartridge that I use with the Mantis. Definitely worth considering.