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TJC

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About TJC

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  1. TJC

    Velocity plateaus in load testing: Why?

    Scott Satterlee is doing a course in the U.K.... https://m.facebook.com/roundhousefirearmstraining/
  2. It’s a debate. Enjoy it. You could be 100% right or I could be. What we can probably agree on is that neither of us will ever be able to prove it on the range. I’m certainly not a good enough shooter for it to matter.
  3. If it is basic and maths why do different apps account for it differently ? I love Brian’s work and follow him religiously but he’s saying we need a custom curve for bullet, he’s saying spin drift is more than many other ballisticians and he’s saying coriolis matters....and he’s selling software to measure and compensate for these. The truth is the best shooters in the word don’t use it and we all know in our sport everyone chases performance the the enth degree. If it made a difference at the enth degree shooters would embrace it religiously. You need to ask yourself why they don’t. PS I don’t they think are flat earth examples at all. They are simplistic for sure but they make sense don’t they ? The earths atmosphere moves with the earth. Outside of the atmosphere coriolis does exist, is extremely material but for the few seconds of bullet flight it doesn’t matter. Its super interesting but the reality is nobody has ever conclusively proved it matters for our sport. That in itself is interesting. There is argument and debate but if it is as simple, calculatable and basic physics as you say then why is there so much debate and discussion ? Is it because shooters have and haven’t seen the difference after firing billions or rounds downrange ?
  4. Jacob gives a very simple example of Felix Baumgartner, that guy who jumped from space. He took several hours to ascend to the edge of the atmosphere at 128k ft and then jump back to Earth in free fall for almost 5 minutes. Where did he land...pretty much exactly where he took off from. How is that possible if the earth is rotating around it’s axis at 1,000 MPH. The Coriolis Effect says he should have landed in the Pacific Ocean but he didn’t. In the two hours he took to go up the earth moved 2,000 miles (actually less because he wasn’t on the equator). Now think about a bullet. It doesn’t stay airborne for more than a few seconds and it doesn’t go that high either. The earth’s atmosphere moves with the rotation of the earth. If coriolis mattered and I wanted to travel from London you Cardiff I would hire a helicopter and hover. The 150 miles would close in 10 minutes or so and all I would have to do is hover 25 feet above the ground. If the earth moves at 1,000 mph how can an airplane travelling at 500 mph from say Madrid to Tel Aviv ever arrive ? It’s because the atmosphere is travelling at the same speed as the earth. If it wasn’t, we would have constant cyclones.
  5. Says most of the leading precision rifle instructors and top competitors. It’s actually common knowledge that most turn off this feature. Attend any high quality course and this topic comes up time and again. If you are genuinely interested have a listen to this podcast by Jacob Bynum who is widely regarded as one of the most respected instructors in the world. He gives some amusing examples why coriolis doesn’t matter in shooting. https://itunes.apple.com/gb/podcast/gear-tasting-radio/id1203483156?mt=2&i=1000433535484
  6. You shouldn’t account for it because ballistic apps grossly over-calculate the impact. That is why most shooters turn off the coriolis calculation on their Kestrels.
  7. It has no discernible impact in shooting sports.
  8. TJC

    Hornady 208gr BTHP in .308Win

    I tried the 208gr AMAX and it stabilised fine in a 1:12 but I ran into pressure signs before I could get enough velocity. Good accuracy but not enough velocity to take advantage of the high bc at distance.
  9. TJC

    65 creedmoor powders

    Agreed. I’m getting 2810 FPS with 43.3gr RS62 in Lapua SRP brass with the Berger 140gr and am getting low single digit SD in a 26”. 44.0gr gives me almost 2900 FPS.
  10. TJC

    Velocity plateaus in load testing: Why?

    Do the test 5 times with the same loads and then see if you have the same nodes or plateaus. Evidence from those who have tried it says no which basically suggests the 10 round process is not repeatable and is therefore statistically irrelevant.
  11. TJC

    Straight line recoil

    Pan works great for movers !
  12. TJC

    Hog Saddle Technique

    You can do either and it largely depends on the shot but more importantly the quality of the tripod and it’s ability to manage the weight of the firearm. Free recoil is increasingly being employed but it requires total confidence in your equipment and most importantly in your ability to use the trigger without subjecting the rifle to any movement whatsoever. Those doing this in competition are often using trigger weights at or under 1lb and with 6.5 and increasingly 6mm rifles that weigh 20lbs . If that’s not you, then being more physical with the tripod is the way forward. Try to remain square behind the rifle, apply the proper fundamentals and don’t fight the recoil / don’t load the tripod too aggressively and try to keep your legs locked - bend at the waist forward not at the knees. Tripod height for standing should be roughly at the bottom of your chest. Finding a comfortable spot for your non-shooting hand is often the challenge. Finally, dry fire...a lot.
  13. I’d be tempted to explore the 224 Valkyrie over the 6.5CM especially if you are shooting inside 600 yards and want a longer barrel life. Factory ammo is probably easier to obtain in the 6.5CM but 224 ammo is crazy cheap in the US so if you had some imported it would probably still be cost effective esp factoring in barrel life.
  14. TJC

    6.5 creedmoor and RS62 temperatures

    Me neither without RS60, perhaps someone else will chime in. Average for 6.5 CM should be 2500-3000 but if you’ve been pumping them out at 3000 FPS with N550 then that could be it, i bet you’ve got some throat erosion ? I’ve heard good things about the 147 but you have to put them down at 2700+ to get optimal stability from a 1:8 twist, 1:7 seems to be a popular option for this particular bullet.
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