Well, well, well - I do believe I'm there - after 2 years...

Well, well, well - I do believe I'm there - after 2 years...

This is a discussion on Well, well, well - I do believe I'm there - after 2 years... within the Defensive Rifles & Shotgun Discussion forums, part of the Related Topics category; This may be premature; I may be overly optimistic; I may be desperate , but I'm sayin' two great days at the range pretty much ...

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Thread: Well, well, well - I do believe I'm there - after 2 years...

  1. #1
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    Well, well, well - I do believe I'm there - after 2 years...

    This may be premature; I may be overly optimistic; I may be desperate , but I'm sayin' two great days at the range pretty much indicates I've found what I was looking for.

    Two days ago I shot some really good groups with a 14.5" BSF carbon fiber barrel (actually a pistol configuration) and did so for 25 shots. I used 77 gr SMKs (Sierra MatchKing) and 23.2 gr (max recommended load) of IMR 8208 XBR in Lapua cases with Federal 205M primers. I tried my best to make Varget work, but at its max charge, it was 137 fps slower than 8208. The SD and ES was pretty good too, 11.7 fps and 41 fps.

    Then today, I pushed the charge past the recommended max by 0.1 gr which set the charge weight at 23.3 gr. I chrono'd the first 20 of 25 rounds and got an ES of 30 fpa and SD of 8.9 fpa. There were NO pressure signs. And, of course, it will haunt me for the rest of my life that I didn't chrono the last 5 But, I have a good reason.

    I was shooting at 50 yards and I wanted to see what would happen at 100 yards. Well, my PRS buddy was to my right and he had a target set up at 100 yards. There was a ShootNC that someone had left from another time that my buddy wasn't using so I wanted to shoot the last 5 at it. My buddy was using his new LabRadar chronograph (everybody wants to be like me ) and I thought if I pointed my LR toward his target, we might get interference. But we wouldn't have because I had already changed the channel frequency on my LR, but that seemed to have slipped my senior mind So, I didn't chrono the last 5.

    I adjusted the ATN scope from 50 to 100 yards and fired a shot. We couldn't find it. I had adjusted the scope in the wrong direction and shot over the top of the target. I picked a lower spot and put the last 4 in a 0.8 MOA group. At 100 yards, even with a 20x scope, those target features look mighty small.

    So I think I'm there, ES/SD = 41 fps/11.7 fps one day for 25 shots and great precision. Then for 20 shots, an ES/SD = 30 fps/8.9 fps. The groups were a bit larger, but that's really on me. I could tell I was more interested in numbers than groups and I let my focus drift a bit. Not bad groups, but not what I want, but again, today was on me.

    OK, now that I've mastered reloading, I wonder if there are any good crochet clubs in my area???
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  2. #2
    Nix
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    Nice!

    (Try fly tying next......)
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    So what was the issue? I would like a summary report please.
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    How about you take up wiring DCC decoders in Z-scale locomotives.
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    Quote Originally Posted by sdprof View Post
    How about you take up wiring DCC decoders in Z-scale locomotives.
    Strange you should say that. For a microcontroller demo project, I and some students set up a model satellite control for a HO scale train. I machined out a "satellite" on my lathe and installed IR LEDs in it to transmit signals to the train. I used a 40kHz carrier to send PWM signals to the train. The satellite was hung way above the train, however we did use a cable as an "uplink" to the satellite.

    I designed an analog amplifier and decoder for the train and installed a photodiode in it glass top observation car. The train received pure DC from the rails but the motor was isolated from the rails and powered via a bipolar power switching transistor to which followed the PWM signal from the satellite. Boy that was a fun project!

    Ahhh, the memories!
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    in Gun Free Zones.

  7. #6
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    Quote Originally Posted by Struckat View Post
    So what was the issue? I would like a summary report please.
    I'll get back to you on that. Had to run a crisis mission for a friend that fell. Tomorrow we take off early for Knoxville on yet another crisis mission for my wife's brother. He has a number of health issues, including a deteriorating mind, and he's got a problem.

    Hopefully, while my wife tends to him, I can get on some WIFI somewhere and stay in touch. If not, it'll be Tuesday before I can get back on line.

    And I have an Aero Precision M4E1 Stripped Lower Receiver coming in tomorrow. I guess that will just have to wait.
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    We don't have a gun problem in the US, We have a people problem.
    The problem we have is people that want to kill large numbers innocent people
    in Gun Free Zones.

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    Quote Originally Posted by Tangle View Post

    OK, now that I've mastered reloading, I wonder if there are any good crochet clubs in my area???
    Up here in FFG at your alternate range, there is an active quilters guild - and a sewing machine embroidery group. I'm sure the ladies would love to have you join them!

    (OUCH!!!!)
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  9. #8
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    Quilting - hmmm, now there's something one could get into!
    We don't have a gun problem in the US, We have a people problem.
    The problem we have is people that want to kill large numbers innocent people
    in Gun Free Zones.

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    Congratulations! I know you have been chasing this for some time.
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    That is good news! Hopefully you can repeat those results. Of course if you do you'll have to find the next challenge!
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  12. #11
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    Quote Originally Posted by Struckat View Post
    So what was the issue? I would like a summary report please.
    @Struckat , after you asked that, I did a lot of thinking about it. My conclusion is, I don't know for sure.

    Where the breakthrough came, if it proves to truly be a breakthrough, was when I decided to load 20 rounds with 77 gr SMKs at the max load for whatever powder I chose and use Hornady, Sig, Lapua, and Winchester cases and see what happens. What happened is numbers looked good. The accuracy looked good, but that was of secondary interest - the numbers was what I was focusing on. The Winchester cases produced a significantly lower velocity than the other three, but the numbers looked pretty good.

    Lapua won the test - but not by much. So, I loaded up 25 rounds with 77 gr SMKs and Lapua cases. It just happened! Good numbers, good accuracy and the second test produced very similar results so I was seeing repeatability.

    I think now, I'm going to shoot at least two more sets of the "magic" load to see if the numbers/accuracy hold. I'm just a bit nervous about this as I've seen good go bad many times. But what's different about the last two tests is the number of shots per charge. Twenty shots pretty much tells the truth.

    As a matter of fact, being the incessant number cruncher I am, I did something that produced some profound results! Upon review I recalled I had 25 shots of the 23.2 charge and only 20 of the 23.3 charge, nonetheless, the first 25 that looked so good, was shot on 11/22/2019. Two days later, 11/24/2019, I shot the same components but with a charge of 23.3 gr - 0.1 gr higher. Here's the stats for the two tests - not to the profound part yet:

    Vavg high low ES SD
    11/22/2019 2567 2586 2545 41 11.7
    11/24/2019 2583.7 2596 2566 30 8.9

    I wondered what would happen if I did the stats on the entire 45 shots as a group??? Given the lower charge would produce lower velocities and and hence a lower average velocity than the higher charge, if this were going to make any sense I would have to "normalize" the groups. I found the difference in the average velocity was 16.3 fps. So, I added 16.3 fps to each of the 25 lower charge velocities. Did I mention I am an incessant number cruncher??? I then calculated the average velocity for the adjusted group. It was 2583.7 fps. Nothing special in and of itself, but look at the average for the higher charge in the table below and the average of the adjusted group - they are exactly the same! I honestly don't know how that could be, but I've checked and rechecked for an error, although I am not that familiar with the term , I don't see anything wrong! The average of the higher charge group and the adjusted average of the lower charge group are the same!

    Well, that's part of the profound, in fact, that's 99.9% of it.

    Now that I have adjusted velocities I can calculate the stats for the adjusted set and the combined set, here's that looks like.

    Notice, of course, the averages are the same, but the highs and lows are different; the ES of the combined group takes on the exact value of the lower charge group, and that doesn't necessarily happen. More likely combining groups will increase the ES; it's worth noting that combining groups can NEVER reduce the ES. Have I mentioned I am an incessant number cruncher????

    Then notice that the combined SD falls between the SDs of the two individual groups, but it is NOT the average of the two individual groups. Rather, it is a separate calculation of the total 45 velocities.

    Vavg high low ES SD
    11/22/2019 adjusted 2583.7 2602 2561 41 11.7
    11/24/2019 2583.7 2596 2566 30 8.9
    combined 2583.7 2602 2561 41 10.5

    So what do we get from all this?

    One, amazingly close results! I'll be awake half the night trying to figure out how the adjusted velocities, that BTW produced entirely different velocities than the higher charge set it was adjusted to, could possible be so "the same".

    Two, two groups, one 25 shots, the other 20 shots, shot two days apart produced incredibly similar stats. This STRONGLY suggest a very high level of consistency of velocities.

    Three this strongly suggests that 20 shots tells the truth about the load and gun.

    Four this strongly suggests these results should be repeatable. I'll be awake the other half of the night wondering if it will repeat.

    Actually, I won't; I'll run the same charge today and see if it repeats - this is makin' me nervous.
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    We don't have a gun problem in the US, We have a people problem.
    The problem we have is people that want to kill large numbers innocent people
    in Gun Free Zones.

  13. #12
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    Congratulations! I know how this has haunted you over the last 24 months.

    Now, would ya' tighten up those darn groups?!?!?!?!?!??!!?

    Be careful on the road too.
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