quick question re zeroing holosun 403c

[old lady new shooter]

I adjusted to a rough zero at home by looking through the bore at the target and then without moving the gun looking through the sight. Now I will finally be going to the range and need to properly zero it.

Being that this gun is for home defense, and the furthest distance I could be firing inside my house is just under 17 yards, with expected actual distance less than that, I want to zero it at 11 yards, selected because due to COVID considerations I have to go to an outdoor range that only has set defined target distances of which the first two are 11 yards and 25 yards.

The instructions say "Each left or right click is for one adjustment equivalent to 0.5MOA value."

The instructions on the sight-in target say "Scope graduations are usually 1/2 inch or 1 inch at 100 yards. For 25 yard range adjustment must be 4 times amount shown on grid. In a scope having 1-inch graduations you would have to move 8 graduations right and 24 graduations up to bring the sample three shot group [which is located at "2R" and "6U" on the grid] to the center of the target.

So first of all, in general I would like to know how "MOA" translates to inches?

Secondly, how many clicks do I need per grid square to zero at 11 yards? The grid squares are 1" by 1".

Thanks in advance.

 

[jmorris]

That’s very close for a zero with an optic that high over the barrel, it might have enough adjustment. Might just go to the end of adjustment and see if the impact is still low or not.

I would be more inclined for the 50/200 method and just count on being - sight height up close.

While I was at the range, with targets that close, I might just try a few rounds with the optic off, just to see if I could count on myself alone that close.

 

[Texas10mm]

I doubt you're going to be able to zero a RD at 11 yards. Is this on a handgun or something else?

All my centerfire red dot sighted handguns are zeroed at 25 yards. That provides allows me to hold on a 6" target at any range under that and stay on target.

My red dot equipped Ruger PCC is sighted in at 50 yards, my AR rifles in 223 at 100, the AR9 pistol at 25.

Anyway, at 11 yards you would need ~19-20 clicks per inch.

 

[bratch]

The instructions say "Each left or right click is for one adjustment equivalent to 0.5MOA value."

The instructions on the sight-in target say "Scope graduations are usually 1/2 inch or 1 inch at 100 yards. For 25 yard range adjustment must be 4 times amount shown on grid. In a scope having 1-inch graduations you would have to move 8 graduations right and 24 graduations up to bring the sample three shot group [which is located at "2R" and "6U" on the grid] to the center of the target.

So first of all, in general I would like to know how "MOA" translates to inches?

Secondly, how many clicks do I need per grid square to zero at 11 yards? The grid asquares are 1" by 1".

Thanks in advance.

At 11 yards 1 MOA is approximately .11” so 1/2MOA would be .055”. 18 clicks will get you .99” so pretty close to 1”.

 

[old lady new shooter]

At 11 yards 1 MOA is approximately .11” so 1/2MOA would be .055”. 18 clicks will get you .99” so pretty close to 1”.

Thanks bratch.

Jeff just told me .5 MOA means ½" at 100 yards, so my math came out exactly as you just said. Which means the question is whether there are enough clicks available to zero it at 11 yards. If not I guess I could zero it at 25 yards, I will just have to remember that if I want to hit exactly if push comes to shove in my house I would have to aim a tiny bit high.

 

[bratch]

Thanks bratch.

Jeff just told me .5 MOA means ½" at 100 yards, so my math came out exactly as you just said. Which means the question is whether there are enough clicks available to zero it at 11 yards. If not I guess I could zero it at 25 yards, I will just have to remember that if I want to hit exactly if push comes to shove in my house I would have to aim a tiny bit high.

I’d probably zero an inch low at 25 yds (gives a 50 yd zero) and call it a day. I believe you live alone so you probably won’t be taking any hostage shots to save a loved one where sight to bore offset actually matters. In that case you should be aiming COM and an inch up or down on a good COM hit won’t matter.

 

[old lady new shooter]

I’d probably zero an inch low at 25 yds (gives a 50 yd zero) and call it a day. I believe you live alone so you probably won’t be taking any hostage shots to save a loved one where sight to bore offset actually matters. In that case you should be aiming COM and an inch up or down on a good COM hit won’t matter.

Yes, no hostage shots, but that doesn't mean there might not be a need for a head shot. Honestly I hope the range is the only place I ever have to shoot any of my firearms but if G-d forbid that turns out not to be the case, I want to be as well-prepared as possible.

 

[bratch]

Yes, no hostage shots, but that doesn't mean there might not be a need for a head shot. Honestly I hope the range is the only place I ever have to shoot any of my firearms but if G-d forbid that turns out not to be the case, I want to be as well-prepared as possible.

Here are various ballistic tables for an 11yd, 25yd and 50 yd zero. You can look at the inches off and try to decide what looks the best to you.

 

[9mmepiphany]

IIRC Holosun expects their 403/503 series of sights to be close at 50 yards.

Because of the additional offset (height over bore), as opposed to their 510 series, I have my doubts that there is sufficient adjustment to zero it as close as 11 yards. If you go with a 25 yard zero I think you'd be better served

 

[old lady new shooter]

Here are various ballistic tables for an 11yd, 25yd and 50 yd zero. You can look at the inches off and try to decide what looks the best to you.

View attachment 936641 View attachment 936642 View attachment 936643

Wow, thank you, that is very useful!!!

 

[old lady new shooter]

IIRC Holosun expects their 403/503 series of sights to be close at 50 yards.

Because of the additional offset (height over bore), as opposed to their 510 series, I have my doubts that there is sufficient adjustment to zero it as close as 11 yards. If you go with a 25 yard zero I think you'd be better served

You might be right. I guess I'll find out.

And then when I get a different sight I get to do it all over again.

Well, learning...

 

[9mmepiphany]

And then when I get a different sight I get to do it all over again.

If you get another Holosun, get one with the 65MOA ring around the 2MOA dot. You can use the pips on the ring for your offset at closer distances

 

[old lady new shooter]

If you get another Holosun, get one with the 65MOA ring around the 2MOA dot. You can use the pips on the ring for your offset at closer distances

Part of my brain is thinking the problem with the 403c for my purposes seems to be the light sensor, in which case maybe one without that feature would be OK.

The other part of my brain is thinking about an Aimpoint H-2. For which I have to get past thinking it's expensive, i.e. maybe it's worth it to get 100% definite reliability.

 

[old lady new shooter]

If you get another Holosun, get one with the 65MOA ring around the 2MOA dot. You can use the pips on the ring for your offset at closer distances

By any chance do you have a picture of what that looks like?

 

[old lady new shooter]

Because of the additional offset (height over bore)

They actually supplied a second mount which I think has little or no offset. I didn't try it or even look at it carefully.

There sure are a lot of moving parts to learning a whole new platform when the only thing a person ever shot previously was revolvers, which are the epitome of simplicity, the major reason I gravitated to them to begin with.

 

[JohnKSa]

Yes, no hostage shots, but that doesn't mean there might not be a need for a head shot. Honestly I hope the range is the only place I ever have to shoot any of my firearms but if G-d forbid that turns out not to be the case, I want to be as well-prepared as possible.

If it were I, I'd go with the 50 yard zero. Zero it about 1.3" low at 25 yards.

Why? Because then all the shots will be about the same distance below the aiming point over the distance you're interested in.

Look at the 11 yard zero in the tables bratch has provided. Between the muzzle and 17 yards, the point of impact will change from 3.0" below the point of aim to 1.6" above the point of aim. That's a change of 4.6" in elevation point of impact over the range you intend to use the gun. If you're worried about precision, you've made your life difficult. If you don't estimate the range right, you could easily be a couple of inches off from where you want the bullet to hit. And the bullet could hit either below or above the aiming reticle depending on the range.

Look at the 50 yard zero. Between the muzzle and 17 yards, the point of impact will change from 3.0" below the point of aim to 1.8" still below the point of aim. That's a change of only 1.2" in elevation point of impact over the entire range you intend to use the gun. That's a reduction of almost 4x in the elevation change over the range that's important to you.

With a 50 yard zero, you can always hold your reticle 2.4" above where you want the bullet to hit and the bullet will always hit within 0.6" in elevation of where you expect it to, regardless of range (out to 17 yards). Yes, it will never be dead on--it will always hit lower than the reticle, but you won't have to correct for distance at all, as long as you're satisfied with hitting about a half inch higher or lower than you expect to hit and as long as you practice holding 2.4" above where you want the bullet impact to be.

An additional benefit is that if you ever do want to take longer shots with it, a 50 yard zero is pretty useful for that, while an 11 yard zero is going to be nearly useless.

 

[old lady new shooter]

If it were I, I'd go with the 50 yard zero. Zero it about 1.3" low at 25 yards.

Why? Because then all the shots will be about the same distance below the aiming point over the distance you're interested in.

Look at the 11 yard zero in the tables bratch has provided. Between the muzzle and 17 yards, the point of impact will change from 3.0" below the point of aim to 1.6" above the point of aim. That's a change of 4.6" in elevation point of impact over the range you intend to use the gun. If you're worried about precision, you've made your life difficult. If you don't estimate the range right, you could easily be a couple of inches off from where you want the bullet to hit. And the bullet could hit either below or above the aiming reticle depending on the range.

Look at the 50 yard zero. Between the muzzle and 17 yards, the point of impact will change from 3.0" below the point of aim to 1.8" still below the point of aim. That's a change of only 1.2" in elevation point of impact over the entire range you intend to use the gun. That's a reduction of almost 4x in the elevation change over the range that's important to you.

With a 50 yard zero, you can always hold your reticle 2.4" above where you want the bullet to hit and the bullet will always hit within 0.6" in elevation of where you expect it to, regardless of range (out to 17 yards). Yes, it will never be dead on--it will always hit lower than the reticle, but you won't have to correct for distance at all, as long as you're satisfied with hitting about a half inch higher or lower than you expect to hit and as long as you practice holding 2.4" above where you want the bullet impact to be.

An additional benefit is that if you ever do want to take longer shots with it, a 50 yard zero is pretty useful for that, while an 11 yard zero is going to be nearly useless.

I did not yet study bratch's tables carefully, although I immediately saw how useful they are.

You make a good point. I will think about it.

If I did want to zero it at 50 yards, that is one of the fixed target distances at the range, I wouldn't have to kludge it from 25. (Assuming I could even see the target from 50 yards away, but that's a separate issue.) The whole list is 11, 25, 50, 100, 200, 300.

 

[JohnKSa]

Because bullets can't fly in a straight line due to gravity, zeroing is always a compromise except when shooting competition where the target will always be at precisely the same distance. The goal is to choose the compromise that is best for your application. In some cases it can make sense to pick a compromise where the line of sight and the bullet path never coincide over the range of distances that the firearm will be used. It is counterintuitive, and it can be sort of irksome if you're the kind of person who likes things to work out very neatly.

If you can zero effectively at 50 yards, that's probably the best way to go vs. doing it at 25. If you have trouble with the 50 yard target, you're really not hurting yourself much at all by zeroing at the closer distance of 25 yards with an elevation offset to make the effective zero 50 yards. Then just do some shooting at the closer ranges to double-check the gun is hitting where you expect it to.

 

[old lady new shooter]

just do some shooting at the closer ranges to double-check the gun is hitting where you expect it to.

If I'm only using the outdoor range, the only distances I can shoot at are the ones I listed above. I can't practice at say 7 or 15 yards.

 

[9mmepiphany]

By any chance do you have a picture of what that looks like?

 

[9mmepiphany]

Part of my brain is thinking the problem with the 403c for my purposes seems to be the light sensor

Turn it off

 

[benEzra]

If you get another Holosun, get one with the 65MOA ring around the 2MOA dot. You can use the pips on the ring for your offset at closer distances

I used to have an Eotech optic on my AR (loved it) which had the same reticle as the ones 9mmepiphany posted, and shot many CQB matches with it. With the dot zeroed at 50 yards, at across-the-room distances the bottom center of the ring was spot-on; as the range opened op, the point of impact would rise to match the dot at 50 yards, be an inch or two high at 100, and drop back to the dot at 200.

At any reasonable distance, the point of impact would always fall on a line between the bottom center of the ring and the dot; past 25 yards, simply putting the dot on the target was good out to 250 yards or so.

 

[benEzra]

Also, if the optic has never been zeroed before, it’s good to start at 11 or 25 yards to get it pretty well aligned (shoot a couple of rounds while aiming at the center of the target and see where those rounds hit, adjust the optic to move the impacts toward the center or a bit below center, then repeat). Once you’re roughed in at close range, move the target back to the desired range and repeat, shooting 3 rounds and then fine-tuning the adjustment at the desired range.

There is nothing more frustrating when zeroing than to start too far away and have your rounds missing the paper in some unknown direction.

 

[old lady new shooter]

View attachment 936658

Thanks.

 

[old lady new shooter]

Turn it off

If you mean manually turn on battery operation, I tried that.