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Long Range Rifle/Scope/PRS question(s)

Discussion in 'Rifle Country' started by Walkalong, Dec 21, 2018.

  1. Varminterror

    Varminterror Member

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    This
     
  2. Walkalong

    Walkalong Moderator

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    Two shots at 94 degrees were 2861 & 2867.
    Using scope height of 1.90. Mils, .1 clicks
    Berger 105 Hybrid. 1.256 long, .243, 105.0, 0.536 single BC
    zero offset
    1 in 7.5 twist, RH

    I did not write down what mils hit where, should have, IIRC 7.1 hit at 1K and 3.6 hit at 690.

    If I input 7.1 in the trajectory calculator it gives my 2690.3 FPS. Can't be.
    Then if I use Strelok/phone to calculate weather it it just dropped to 74 degrees, 2541 FPS & 8.2 mils. I have something backwards, Jeff from work was doing this the same way and having to use trajectory calculator and adjust giving him weird FPS.

    I watched a couple utube vids on Strelok but I must be missing something.

    There are two places to input fps, one on the page with bullet length/dia,weight,bc, etc, along with a line to input zeroing weather, offset, g1 or g7 ect.

    Tap that and a new page comes up with multiple lines to input fps vs speed, it says you can leave the fields zeroed except for the first two lines. I really only have data for one temp though. Fellow on utube put the same value on both lines, but he also was using trajectory calculator to fix it.

    I am having the same issue with Strelok and AB, so it has to be me. ;)

    Found the other weather input spot, tap the weather line ??F/?InHg?/?? to get to the "enable zeroing weather" page. Has a line for temp, pressure, humidity. You can tap the "metered" icon and use the phone to calculate the weather, then select "use these values". Then go back and calculate again.
     
    Last edited: Jul 4, 2019
  3. Nature Boy

    Nature Boy Member

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    Here it is with Ballistics AE

    F2B1DE40-7588-41AD-B429-C6A9BCF43478.png

    As an aside, I have my scope hight at 1.9” too.

    I have a 1k gong I shoot on at a buddy’s farm. Like you, my actual mils are less than what the calculator says but there’s an elevation drop from our shooting point to the target.

    In your case, either the target is a little shorter than 1k or it’s below you......or a bit of both

    This is why this crap ain’t easy.
     
  4. z7

    z7 Member

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    for corrections to software inside of 600 yds, tweak muzzle velocity, for corrections beyond that, tweak the bc value on the bullet, berger advertises a number, but that won’t hold perfectly true for your gun. Also the environmentals for the shooting day matter

    It’s ok to tweak the software so it tells you the truth, the gun doesn’t lie
     
    Last edited: Jul 4, 2019
  5. Varminterror

    Varminterror Member

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    @Walkalong - you have mixed BC units. If I put in 2680fps, .536, and use G7 calculation, I get 7.2mils hold for 1,000yrds from StrelokPro. No doubt in my mind, that’s the answer to your problem. That’s why truing your velocity backs you down to 26xx FPS - it thinks you’re shooting an exceptionally high BC.

    DA45E97F-4058-4FB5-83F6-729D71C62C85.jpeg

    If you’re at 2864fps with the Berger Hybrid, you should be ~4.4mils at 690 and ~8.5 at 1000. I shot 2800-2900 all last season with my Seekins and 105 Hybrids, and that’s consistent with my DOPE.

    Also supported by StrelokPro, Hornady 4DoF, and ABMobile:

    1CCA8244-09F1-4508-A983-032E75C4B8C7.png
    35E5DCC6-5D47-4EC4-B23F-7A2605B0D8A0.png
    DB49D43C-FBF0-4499-9295-F9CC501874EA.png

    49CF3218-E8F2-474A-B77C-4FF43DDE700D.png
    770C6A47-2A1D-4D9A-9415-D05286000405.png
    49DDC2E1-9791-4465-AF4E-29AB3B175902.png
     
  6. MCMXI
    • Contributing Member

    MCMXI Contributing Member

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    But he dialed up 7.1 mils, hit the target at 1,000 yards, then measured the MV to be 2,865 fps. That's the issue right? His app, just like everyone else's app shows somewhere around 8.2 to 8.4 mils needed for 1,000 yards but he hit the target with a mil less comeup. That's my understanding of the issue.

    @Walkalong, how did the Seekins shooting the 6mm CM correlate to your app data?
     
  7. MCMXI
    • Contributing Member

    MCMXI Contributing Member

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    @Walkalong, my approach would be to confirm every variable that I can reasonably measure. For instance, have you done a box test with that Bushnell scope to convince yourself that it's tracking properly? I know it was on the Seekins rifle and I remember that you took it out for some long range shooting a few weeks back, so did it perform as expected on that outing? Validating scope tracking should be one of the first tests for any rifle where dialing is expected. So many shooters just assume that it's good to go. Some shooters validate the scope by shooting at long range, but a 100 yard box test can be very helpful to get an idea of what to expect.
     
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  8. Varminterror

    Varminterror Member

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    The combination of .536G7 and 2690fps solves forwards what his “truing” did backwards. That doesn’t solve why he hit almost a mil higher than expected, but it does answer why his truing effort gave 2690fps for his MV.

    Think about it - if all of these calculators ran by different folks are showing ~8.4 with .536G1 and 2864fps, but he hit with 7.1, how could his BC input he used be correct if it tells him his true velocity is 200fps slower? Simple - the input wasn’t right. Putting .536G7 and 2690fps into the calculators lines up with his truing output. We know the BC of the 105 Hybrid isn’t .536G7, and we know he’s not getting only 2690fps.

    If 7.1 is correct DOPE for truing at 1,000, with a .536G1 locked in, then his MV trues to 3039fps (2900ft DA). Equally, the 3.6mil come-up at 690yrds would true to 3110fps.

    BF0543A3-FB5A-4E94-8340-9284540970E7.png


    @Walkalong - how big were your targets? And where on target were your impacts?

    I can tell you, just from my data book at the last match I shot a couple weeks ago, I have confirmed DOPE in my 6 creed, 7.5” twist, using StrelockPro running the 105Hybrid at 3083fps and a .275G7, 2/2 impacts at 702yrds with 3.7mil correction, 2/2 at 695 with 3.6, 2/3 at 964yrds with 6.3mil elevation, 3/3 at 952 at 6.1mils. (That would put me at 6.7mils at 1000). So 7.1 at 1,000 could be correct for a Dasher with the 105 Hybrid, but there’s no way your velocity starts with 28, and damned sure it doesn’t start with 26...
     
  9. Walkalong

    Walkalong Moderator

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    Yea, I need to shoot it with my range finder next time, and my guess is yes it is a bit lower. I did shoot other steel, but no the 1K. I would hope they got that one right.
    Let me check that.
    No, it is off too, meaning I am doing something wrong in the ballistic app.
    Both scopes are doing the same thing, but that is a good idea.
    I cannot see the impacts at 1K, at 690 we were dead on.
    My chrono showed two shots, 2861 & 2867 at 94 degrees. That seemed logical to me at a startingish/fire forming load, definitely not max load.

    I just looked up the Berger 105 hybrid, and when I switched from G1 to G7 in the App I did not change the BC to go with it *Sigh*, but I still get 8.2 at 1K if I input 2865 at 94 degrees. 4.4 Mils for 690.
     
    Last edited: Jul 4, 2019
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  10. Walkalong

    Walkalong Moderator

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    No matter what I do it doesn't come out at 7.1 fro 1K and 3.6 for 690, very frustrating. The program isn't very intuitive for me, my mind just doesn't work that way I guess.

    Like I can't play chess, I know how, but I couldn't beat a good ten year old. :)
     
  11. Walkalong

    Walkalong Moderator

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    Me too. If I change it to .275 at 2680, I get 9.6, which makes sense because 2680 is so slow. Change it to 2865 FPS and I get 8.2.

    Chrono lying to me? Primers showed zero pressure. I'll load some more and go chrono some this week.

    At 94 degrees

    2950 FPS gets me 7.6 at 1K

    3000 FPS gets me 7.3 at 1K & 3.9 at 690.

    3050FPS gets me 7.0 at 1K and 3.8 at 690


    With the Seekins I chronoed some 108 Gr ELD factory ammo at an average 2905 at 72 degrees

    If I use that in Strelok Pro

    2900 @ 72 degrees zeroing weather using 94 temp

    4.3 for 690 and 8.0 for 1K. I don't remember what we made hits at at 580 and 690 with it. *Sigh*

    Still very frustrated.
     
  12. Varminterror

    Varminterror Member

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    If you know you were centered POI on POA for your 690 targets, I would rely upon that for your mental truing, if not the real truing. Say you’re shooting an IPSC at 1,000, that’s a 30” target, 0.8 mils tall. If 7.1 mils held center mass on an IPSC hit bottom edge, which I know you’re solid enough in group size to deliver with that rifle, you might be .4-5 mils disjointed POI vs. POA, but getting confirmation on impact. Makes a pretty significant difference in your truing effort, and might explain why you don’t line up.

    If you’re shooting 1moa targets, then the above would be moot, but most 1,000yrd target steel is pretty generous.
     
  13. Varminterror

    Varminterror Member

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    If I understand correctly, we had two issues:

    1) His range data didn’t line up with the calculator, so he needed to true the curve.

    2) Upon truing the curve, his result was a nonsensical solution - 2690fps.

    The answer to #2 was a simple mistake to make in StrelokPro, mixing G1 and G7 profiles.

    The answer to #1 LOOKS like his muzzle velocities are higher than his chrony reading, but without knowing more on the load data, and confirming more at the range and with another chrony, that’s just a “most likely” on the list.
     
  14. Walkalong

    Walkalong Moderator

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    Fixing the G7/wrong BC didn't make as large a difference as I thought it would, I was hopeful that would "fix" it, but it made a small difference.

    I'll try to get to the 100 and 300 yard range soon and shoot, both to chrono and to get drop at 300.

    I guess I thought once I got velocities at a couple of temperatures (Only really have one with the Dasher) all would be well, but I guess the program can only do so much. So just like a varmint rifle, I need to go shoot it at different ranges and write this stuff down next time. More and better data and the ballistic program will work better, hopefully. :)
     
  15. Varminterror

    Varminterror Member

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    A couple shots on the chrony should have been enough to get in the ballpark to have you on steel as you walked out, even if it wasn’t center mass. Definitely wouldn’t expect it to be off by 200fps, up or down.
     
  16. Walkalong

    Walkalong Moderator

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    I have only fire formed 30 of the 100 brass so far, I haven't shot any of the formed and prepped brass at all, haven't even touched the 30 fire formed cases yet. Plus I am haven't figured out my dope. Yikes.

    I'm going to go fire form some more cases after work today, clean the rifle, FF the rest tomorrow, then clean/size/prep some cases, figure out what charge to use, and shoot them to see what FPS they run at. Then load up for the match. Then after I get my butt kicked/learn a lot, come back home, heal up, work up a load, practice, and be better prepared next time. :)

    I do have a chance to go shoot long range again next week after work, maybe even twice, the fellow I work with who has been bringing me signed up for the match on the 20th. Maybe it won't be too bad.
     
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  17. Walkalong

    Walkalong Moderator

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    I fire formed 30 more rounds after work today. I started out with the full sized Game Changer bag under the stock, but it is bulky high up around the stock and makes it tough to settle in. I ended up with the waxed pint sized GC sitting on top of cardboard pieces. That worked real well. I stopped holding the forend of the stock and just used my left hand to squeeze the GC. I like the waxed bag feel etc vs the standard with the synthetic material. I wasn't sure whether to get the light or heavy pint sized waxed GC, so I went with light. I was concerned to heavy might be too stiff. Dunno.

    My first shot was about 7 clicks low at 100 yards. Dang??? Next shot went in the same hole. I had to adjust 7 clicks to get it right. I don't know for sure how I screwed this up, but I have a real good idea. Anyway, I started over after getting back on at 100. I set the zero stop, and then zeroed out the turret. Then I shot a nice three shot group with three cutting each other in a tight wad. After that I dialed up 9 mils and held down 9 mils and put another one in the group. Then I dialed back to zero and it did not go in the group but it cut the edge of it.

    So I guess I have it right at 100 yards now.

    I ran the first twenty over the chrono at 5 yards. It read 18 of the shots.

    Hi=2855...Lo=2824...Avg=2840...ES=31...SD=9

    I will tumble, size, trim, chamfer/deburr, and load a few of the fired cases and chrono them. I need to go up on the charge a bit. I still have 40 rounds to fire form this weekend. Will bump up the charge a hair to fire form next time. Maybe 31.5 Grs RL-15. I need to figure out what charge weight to go with in the formed cases. Hopefully a little more pressure/velocity will bring the ES down some.
    20190712_161518.jpg 20190712_172304.jpg
     
    Last edited: Jul 12, 2019
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  18. Walkalong

    Walkalong Moderator

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    Magneto Speed chrono question.

    What do you get for the extra cash with this one (On sale) vs this one, doesn't look like $200 more. Anyone what what the differences are?
     
  19. Varminterror

    Varminterror Member

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    I bought a Sporter 2yrs ago, then traded it in to Magnetospeed for a V3 after about a year with it. After a year with the V3, I’d say the price difference is well worth it to me, but the Sporter DOES work.

    I bought the Sporter first because I thought the same as I expect you are right now - is the V3 really worth double the price? An extra $200? After a year with mine, and considering the fact I shoot AR’s and suppressed rifles as much as I do, it was well worth the price to upgrade.

    The V3 computer can hold more strings, but most guys probably won’t notice that particular difference. The interface with the V3 computer is much easier than the Sporter, but the Sporter is serviceable. I had to read the instructions several times over a year to remind myself how to clear a string. Again, not a huge deal, but a deal nonetheless.

    The biggest difference for me is the versatility for mounting. The Sporter cannot be used with suppressors not with tubular handguard which nearly reach the end of the barrel. Nor with handguns (have to have a pic rail on the pistol, so this one is NEARLY a non-difference).

    You CAN buy a V3 bayonet for use with a Sporter computer, and Magnetospeed seemed flexible to trade a Sporter Bayonet for a V3 Bayonet, which would end up something like $75 cheaper than just buying a V3. I chose to replace my entire unit, trading in to Magnetospeed.

    Magnetospeed is a great company to work with, and Ryan’s a great guy. I wanted to trade my Sporter in, but had matches too close together to complete the trade - so I called them. They sent me a loaner V3, I mailed in my Sporter, then I traded in their loaner for my NIB V3 in person at a match we both happened to be shooting a few weeks later.

    If you’re only planning to use it on braked or bare muzzle rifles, and not with suppressors or stub-nose AR’s, then the Sporter works for what you need, and is a lot cheaper. If you own a can, or an AR with less than about 6” of barrel sticking out of the handguard behind the brake, then you’ll likely need a V3.

    BTW - There are a few folks out there making extension struts to hang the V3 from a pic rail or ARCA rail on the stock, instead of from the muzzle. A guy can then shoot the V3 for speed without the POI shift we see when mounting to the muzzle/suppressor. Smaller and less expensive than a LabRadar, and portable, with less aiming issues. I love the LabRadar, but I always use the V3 with my precision rifles because I can pack it along easier and set it up faster and easier to check speed the day before at the match range. The downside has been the POI shift, but with these struts, it’s gone.
     
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  20. taliv

    taliv Moderator

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    Got a link to an arca rail strut?
     
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  21. Varminterror

    Varminterror Member

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    MKM’s Gen 3 has a double clamp, pic & ARCA, currently a pre-order item.

    MKM Magnetospeed strut mount Pic + ARCA

    They also sell ARCA adapters for their previous Gen I. Same site if you already have their Gen 1, or can’t wait for the new version to drop.

    Here’s the Gen 3:
    D4110A0D-2184-4BD7-A38B-273A4BA06BF6.jpeg
    81646E52-DB75-469E-9EDD-D8A01CE36D95.jpeg
     
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  22. Walkalong

    Walkalong Moderator

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    I tumbled and sized 30 fire formed cases (Lapua blue box 6 BR brass). It took some time to sneak up on the right spot for the Wilson threaded FL bushing sizer. The fire formed cases were at 0.00 to +.001 on the Whidden Case Gauge, and -.001 to 0.00 after sizing. I could have just made a button like I have for other calibers, but I couldn't resist the Sirens song with this gauge. It works really well and is super easy to use. Great stuff.

    The sizer reduced the body by .002.

    I bought Wilson .266 & .267 bushings and used the .267. The cases are tumbling now. I measure one of the sized cases and it was 1.556, so I need to research and decide what to trim them to. 1.550 sound right? I bought a case holder for them for my Wilson trimmer.
     
    Last edited: Jul 13, 2019
  23. Walkalong

    Walkalong Moderator

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    Loaded up the 30 cases with 32.0 Grs RL-5 and backed off the seater .035. Got to the range and started to unload when the hospital called, 1 South cannot hear anyone calling in on the nurse call system. At least the range is only about 15 minutes away.

    I get to work, fix the nurse call (Easy fix - Woohoo), then realize I had not clocked in, so I clock in and here I sit killing some time before clocking out and returning to the range.

    The seating pressure felt real good using the .267 bushing, not nearly as heavy as using the factory brass as is, but heavier than I used to use for Benchrest. Felt good, and consistent.

    I will shoot five and see what they do, chrono them, make sure I am on at 100, and save the rest. Then I need to fire form the last of the cases in the batch of 100, tumble, size, trim, load, then use a few (Have to save 80+) to get on steel at a couple of known distances, cross my fingers and go to the match Sat. :)
     
  24. Walkalong

    Walkalong Moderator

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    Cleaned the barrel (Two wet patches, let soak, on wet patch, two dry patches.

    The first target are the 5 fire forming rounds I had shortened getting the new OAL. Still 31 Grs RL-15, CCI-450 primer, Berger 105 Hybrid, but just off the lands now instead of jammed. I chronoed them and they were a bit slower than the fire forming rounds that were jammed into the lands. So not being into the lands lost a little pressure/velocity. Avg=2813 FPS, down from 2840 in the same temp give or take a degree.
    The wet spot is from sweat dripping off everywhere. I kept wiping my face with a towel, but the sweating was constant.
    It was 95 to 97 while I was there, 46% to 52% RH.

    Shot # 2 is hanging out.
    Sight In Before My First PRS Match Pic 1.jpg

    Then I shot a group with 5 of the fire formed cases, now loaded with 32 Grs RL-15, CCI-450 primer, Berger 105 Hybrid just off of the lands.

    Left another one hanging out.
    Sight In Before My First PRS Match Pic 2.jpg

    The I needed to sight in the Seekins again because I did not read the scope directions and did not get the zero stop set. It is actually a very good system, just need to read the directions as it is a bit different.

    I bore sighted it the old fashioned way by looking through the bore. The first shot hit paper, then I eyeballed the reticle to see how much to dial it over and down. Next shot hit right next to the aiming spot in the middle of the paper. Then I shot a five shot group lower left. Left one hanging out again. I am the king of four in and one out today. Then I made another small adjustment and fired a shot at the lower middle target. Good enough. Sam's handling of the rifle vs mine might make more difference than that.
    Sight In Before My First PRS Match Pic 4.jpg


    Now I need to go shoot it at long range and make some good notes for the match next Saturday. (Oh, and load the rest of the brass I fire formed today.)
     

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  25. taliv

    taliv Moderator

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    dang good shooting!

    i take it you're not feeling any buyer's remorse with that impact/foundation lol
     
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