Horus Vision ASLI. It is any good?

Discussion in 'Long Range Hunting & Shooting' started by Michael Eichele, May 4, 2010.

  1. Michael Eichele

    Michael Eichele Well-Known Member

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    Last edited: May 4, 2010
  2. slewfoot

    slewfoot Well-Known Member

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    Cant beat it for the money, well made unit. Had small issue with sun glare at certain angles. The degree marks are easy to see. They come with a nice cover.

    Slewfoot
     

  3. LouBoyd

    LouBoyd Well-Known Member

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    This isn't a comment on the Horus Vision ASLI specifically, only on whether a rifle mounted elevation meter is needed at all.

    When taking any shot there are several variables which need to be determined. I'll assume the characteristics of the ammo and rifle are known. The more important variables are:

    1.Distance to the target. That can be line of sight or "map distance" but they're different.
    2. Wind deflection derived from the continuous wind vector and bullet drag over the trajectory. The hard part is determining the wind vectors.
    3. air density
    4. elevation angle to the target

    Less important (but maybe needed for very long range are cartridge temperature and azimuth.

    Before buying instruments it's worth considering how much each of those affects your accuracy versus distance and what equipment is needed to measure those with the necessary accuracy.
    For moderate range hunting (500 yards?) your senses and practice can be sufficient.

    Laser rangefinders can easily give the distance to the target to +/- 1 yard. Maximum range is just what you want to spend on the device. Visual estimation using stadia range finders (like mil-dot) may be practical if known sized objects are in the field of view but typically have a 10% or greater error. The needed accuracy increases with more the square of the distance.

    Wind speed at the shooters location can be measured with a pocket anemometer or estimated with practice by the "feel" of the wind but downrange winds are even more important than at the shooters location for shooting over about 600 yards. With lots of practice one can get fairly good at estimating wind deflection from mirage, plant movement, and windblown particles, but there are no affordable instruments which can measure wind accurately other than at the shooters position. Visual wind estimation is more difficult in mountainous terrain than on flat ground and also more difficult in low light.

    Those two measurements are the most important to accurate shooting.

    Air density measurement has become fairly simple to measure with electronic or mechanical devices which cost $100 to $200. But one can do a decent job of estimating air density by estimating the temperature, altitude and guessing at the barometric pressure based on the weather conditions then using a lookup table. Shooting accuracy is not as sensitive to air density as to range or wind deflection. Air density affects the drag on the bullet, but it's a secondary effect.

    Likewise, most people can estimate the target elevation angle within 5 degrees with a little practice. Since the data is only useful if you've memorized multi-variable ballistics charts (or enter it manually into a computer) is a scope mounted inclinometer the best way to measure angle? I use a LTI rangefinder which gives the elevation angle with each distance reading. That seems like a more sensible place to locate the inclinometer to me. For most shooting a 5 degree estimate is sufficient for the error to be smaller than wind estimation errors. For shooting on reasonably flat land elevation angle can be ignored to around 1000 yards.

    I've never considered that I need an elevation meter mounted on my rifle. If there was a "complete" scope based rangefiider that measured crosswinds downrange then the ability for the scope to also measure air density and target inclination angle would be useful for internal calculations by the scope's computer.

    I'll not be buying a Horus ASLI. I do have a Horus Falcon riflescope with the H37 reticle and like it very much. It gives accurate windage and elevation holdoffs with no knob twiddling or click counting.
     
    Last edited: May 6, 2010
  4. royinidaho

    royinidaho Writers Guild

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    I quickly plowed through the users manual to see if there are any deal breakers.

    Found non but had to laugh about about it being 'self-adjusting'.........like gravity doesn't work!:rolleyes:

    As LouBoyd mentioned if your LRF provides this info, then who needs one.

    But if your LRF doesn't provide the info this type of device is a must have in my book.

    This one seems sturdy enough though time will tell.

    I wasn't readily able to determine the weight of the device and have a bit of concern of how it is mounted to the three mounting options.

    It appears to slide onto the mount in a horizontal fashion with a friction type set screw to secure it.

    Would not it be better if it slid vertically onto the mount? I'm thinking of big boomers that may require two sets of rings to secure the scope.

    The only reason I don't have such a device at this time is the mounting concern.
     
    Last edited: May 6, 2010
  5. angus-5024

    angus-5024 Well-Known Member

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    Micheal Eichele,
    I purchased a ASLI about 2 months ago and love it. It is a very good unit for the money. I will admit a little bigger than I'd like, but at half the price of an ACI with a spirit level and mounts its a great peice of equipment. I shoot a 10lbs .338 RUM and it has no problems staying put thus far.
     
  6. WildRose

    WildRose Well-Known Member

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    Since we have someone currently looking at ASLI's I was doing some googling and found this thread so I thought I'd resurrect it.

    Yes your laser rangefinder (assuming you have the higher end models) can also give you the angle and cosine.

    Until it fails due to breakage or dead batteries.... .gun)
     
  7. angus-5024

    angus-5024 Well-Known Member

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    Im still useing mine. Even if i get a new LRF, i will keep it on. Just like i would never go on a hunt without knowing how to use my reticule to range. Electronics fail sometimes.
     
  8. WildRose

    WildRose Well-Known Member

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    Yep and usually it's when we need them most.
     
  9. liltank

    liltank Well-Known Member

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    I've got to be honest here. I've owned two. First was the picatinny mount (didn't fit), the second was a scope mount. I had to file off some teeth from the rail to get it to fit w/ low rings. Both would not hold a bubble on level. As soon as I changed vertical angle of the rifle (tilting up and down on the bipod), the bubble would go off level. I checked it against a torpedo level on the scope. The torpedo level would stay level horizontally, but the ASLI would change. I couldn't figure out why I always had to add more windage to the scope than what it called for on my solutions. I ended up ordering a level off this sight. It is a much better option. The angle/cos was off too. It is a sealed unit, so you can't calibrate it to your rifle. Savageshtr had one, and the machining was terrible. He couldn't keep it clamped tight because the screw bottomed out before it was tight enough to hold the ASLI.
     
  10. Outlaw6.0

    Outlaw6.0 Well-Known Member

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    I bought one several yrs ago.... came with the supplied pic rail clamp. The pic rail clamp would not hold (iddy biddy little screw) at any reasonable torque level on my 16lb braked 338 RUM. One trip to the range & it would slide forward.... the Unit didn't sit level in the clamp, which was annoying at worst. I ordered the ring mount thinking "it can't be worse, right?" Wrong, I open my reasonably priced package to find an aluminum, pot metal casting of a ring worm turd.... I think a mount made of Lego's would have been stronger:rolleyes: Then I find out that the clamp bottoms out before it engaged the dovetail of the ASLI.... to the DREMEL you go!! Yeah it worked, but after discovering the FlatLine Ops, the Horus has went down the road...

    The ASLI was pretty well made, the mounts on the other hand....
     
  11. Wile E Coyote

    Wile E Coyote Well-Known Member

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    I have one that is a couple years old and I don't use it. It has a rail mount that didn't hold very well AND setting the screw just dug a hole in my rail. When I tried to "adapt" it to another mount, I found it had a different dovetail. It would fit together but the machined angles were different.

    My preference is for the "Flatline Ops" products. They fit right and once setup properly, they don't move. I'm using them on several .223s, a 7mm RM, a 300WM, and a 308. All are where I originally set them including the 308 which experienced a bit of rough handling when I took a nasty tumble off an ATV last year. Character marks were added to the rifle, "road rash" applied to the operator and an ego was severely dented were the only wounds received. I don't think the plastic housing of the ASLI would have faired as well.

    my .02