Cosine gages

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Paul Wyatt, Jan 3, 2005.

  1. Paul Wyatt

    Paul Wyatt Well-Known Member

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    I'm relatively new to this game, but have been reading posts daily for a month or so and have a question. There have been quite a few discussions about useing cosine indicators; the consensus being that the gages are good, but they lack sufficient detail in reading the cosine to be depended on for long range shots (extrapolation is necessary). If I am reading posts correctly, most shooters are using a PDA with a ballistics program to get corrected come ups/downs, and that the cost of the cosine gages is somewhere in the neighborhood of 90 - 100 dollars.
    My question is why not go with a digital incline instrument that reads the angle to the nearest .1 degree for $100 (http://store.yahoo.com/ascscientific/smardigclin.html). A PDA is being used anyway and the cosine of the angle could easily be fugured using it.
    Give me some help before I do my typical thing and spend $100 only to find that what I did was bass-ackwards.
    Brassbender
     
  2. CAM

    CAM Well-Known Member

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    Brass Bender
    Most PDA programs that I have seen and used only require the known angle not the cos.(program knows the cos)
    Anyway you find the angle will work!
    after you know the angle plug it into the program.
    I think most of the debat is that "the cos X the known distance" WILL NOT WORK AT LONG DISTANCE
    You need to field verify your comeups with the program to know if the info is right for you or adjust the bullet BC to get the program to match your actual drop.
    CAM
     

  3. Mikecr

    Mikecr Well-Known Member

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    I don't see why it wouldn't work just fine. But how you gonna use it in the field?
     
  4. goodgrouper

    goodgrouper Well-Known Member

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    Brass Bender,
    Your link to these digital incline/angle insruments didn't go through. Tell me more about them please, I have not seen them. Where do I get one and how do they work? Also, do you have to attach them to the gun?
    Thanks for your reply in advance! /ubbthreads/images/graemlins/wink.gif --goodgrouper
     
  5. Paul Wyatt

    Paul Wyatt Well-Known Member

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    Goodgrouper;
    The instrument is an ASC scientific model and can be found on their site. Here's what their post has to say about the device:

    The SmartTool digital level is a durable field tool that can be used as a level, plumb and clinometer. It digitally displays angles in degrees, percent slope and pitch (inches of rise or fall per linear foot) to an accuracy of 1/10 degree.
    Controls include:

    ON/OFF - automatic shut-off if left idle for 6 minutes
    HOLD - freeze or unfreeze display readings
    LISTEN & LEVEL AUDIO - beeper will sound at level and plumb
    CALIBRATE - simple two-step calibration procedure (recommended once per day)
    Deg.,%,IN/FT - select display units
    UP/DOWN ARROWS - show direction of tilt to reach level or plumb
    LOW BATTERY - low 9V battery indicator
    Dimensions are 6" x 1 1/2" x 2". Weight 7 1/2 oz. Housed in environmentally sealed polycarbonate housing. 9 volt battery provides up to 120 hours of continuous use.

    BTW, we are from the Provo area, and will be back there in about 10 months. Like to meet you and do some shooting.
    Brassbender
     
  6. goodgrouper

    goodgrouper Well-Known Member

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    Brass Bender,
    thanks for the post, and I would love to go shooting with you when you get back!
    Could you post me the website address for the product?
    Also, I helped a guy this fall with a cool gun (nesika bay rifle) and he said he had parents living in Russia. You wouldn't be part of the Legas family would you??
     
  7. Paul Wyatt

    Paul Wyatt Well-Known Member

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    Goodgrouper;

    You don’t by chance work at Sportsman’s Warehouse in Provo do you? If so, I think you know my son-in-law.

    You have basically the same questions that I have on this whole thing. I think that I have decided to purchase the Smart Tool Digital Inclinometer and not mount it on a rifle – it is small and light and won’t add that much to the pile of stuff that I will be packing along. I have a Hewlett Packard iPAQ PDA that I am installing Exbal on. My plan is to use the inclinometer to read the angle of incline to the nearest .1 degree, enter the information into Exbal on the PDA, and go from there.

    I have arrived at this conclusion because from all that I have read, it seems that the software programs give the best (most accurate) results. Even “W” who manufactures the ACI recommends the use of Exbal. The ONLY criticism of the ACI that I have seen on these posts is that it reads out to the nearest 5 degrees, which some folks claim is not accurate enough for really long ranges. I think that you could site along the top surface of the digital inclinometer and get a reading much more accurate than that, especially when considering that military snipers used to use a protractor and string in the same way. The clincher for me is that the digital unit is essentially the same price as the ACI gage. It just seems to me that in long range shooting there are so many variables to contend with that tightening the degree of accuracy in any area has to improve chances of success.

    Thanks for the chance to talk shooting with you.
     
  8. goodgrouper

    goodgrouper Well-Known Member

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    Brass Bender,
    I do know your son-in-law! He is a great guy. I had him out hitting my gong at 1000 yards before he had shot his first box of ammo with that Nesika! He thought it couldn't be done twenty minutes earlier.
    I was sorry to hear about how his guide wouldn't let him take that trophy muley at 600 yards. He would have drilled it perfectly and actually quite easily! /ubbthreads/images/graemlins/grin.gif
    Yes, I do work at SW in Provo.
    I agree with you on the digital clinometer and a pda with Exbal. Seems like the easiest and most accurate way to go. How do you like your pda? How much is that one? I have a palm pilot, but its old and kind of slow. Need one of those pda's. /ubbthreads/images/graemlins/wink.gif
     
  9. CAM

    CAM Well-Known Member

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    GG
    The link worked for me, you just have to copy between the parenthesis.
    http://store.yahoo.com/ascscientific/smardigclin.html
    BB
    you might could mount it onto your spotting scope or scope stand.
    one other point, when you sight down the top trying to hand hold this thing you might want to tape a straw to the top as a sight line.
    This would look like a POS mounted to your gun!!
    I checked my progam and put in .1 deg just to see if it worked and it changed the clicks at 2K.
    good luck and post back on this thing!
     
  10. Paul Wyatt

    Paul Wyatt Well-Known Member

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    My PDA is really expensive, but you wouldn't need one with everything I have. I have seen some references to some good units on some of the links that you should check out. I bought this one before we came to Russia because I need a lot of storeage and BlueTooth functions.
    Say hi to Tad. I'm sure he will be contacting you to go shoot again.
    Actually the guide that was with him was his brother-in-law (oldest daughter's husband) and he didn't think there was any way the shot could be made. Tad had been shooting well at that range, and I wish he had gone ahead with the shot. Oh well live and learn!
     
  11. goodgrouper

    goodgrouper Well-Known Member

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    Thanks Cam. I got on it now. Nice to see another Utahn on here! What town are you from?
    That's a good idea with the straw, I'll try it!
     
  12. CAM

    CAM Well-Known Member

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    Goodgrouper
    I'm in Bountiful
    Where is your 1K range?
    I've shot with SR90 also on this board out to 1K several times out in the desert.
    He has shot out to 1 mile but I was out of town.
    Do the Orem police use your range?
    Talk with you later
    CAM
     
  13. Paul Wyatt

    Paul Wyatt Well-Known Member

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    Goodgrouper;
    call my son-in-law, he will be getting some stuff that I ordered and had sent to him that you will want to see/try out.
    Brassbender
     
  14. goodgrouper

    goodgrouper Well-Known Member

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    Cam,
    I have several 1k ranges in Santaquin, Elberta, and Mona. My 1400 yard range and my mile range west of Elberta. My 3000 yard range is southwest of Elberta and that's where I plan to unleash the .338 Lapua mag improved this winter.

    No, the police don't use my ranges. They are all on BLM land except the 1400 yard range which is on a cattle rancher's land. He will let me or anyone who agrees to close the gate shoot there!