What is this thing?
- Thread starter Awag1000
- Start date
Charlie tarac macro.
I put it on and my 100 yard zero becomes a 2400 zero
Might have to pick me up one of them.
True. Mine is a Montana hunting rifle that doesn't weigh all that much and beats the shit out of me. And for such an expensive rifle, the buttpad is a g'dam joke.
and the length of the barrel. Long barrels = spread out that recoil. In ELR game, no reason to "save a few inches" of barrel.
This is actually very good advice I hadn't considered. Thank you. Good stuff.
So something that has me really intrigued is first round cold bore hits at a Mile. What kind of weaponized mathematics goes into a shot like that?
I’ve done It a few times.
a sorted out kestrel and a lucky wind call aided with some experience really helps.
Knowing your load - especially what the MV is going to be. Then its Kestrel dialed in and wind call as @Steel head stated
Honestly, CBS impacts are why I have stayed in precision rifles for so long. I literally will fire one round and call it a day - if she hits
A pachmyer decelerator recoil pad would change your life. I have a win m70 featherweight in 30-06 that beat me up worse than my rpr 300wm. Slip on pad made it almost enjoyable.
To true the software to get to a mile CBS, what distances do I need to shoot?
My shooting spot close to home has steel at 530, 1130, 1525 and 1930 and I find if I get my kestrel sorted to those distances a mile is not problem depending on conditions that it can’t predict.
I occasionally get days with minimal winds and I like to use those as most of my locations get very interesting up and downdrafts and wonky steep valley winds.
You really should be recording every shot, it really helps you learn how conditions affect the shot.
I don’t always get CBS at a mile but it does happen and it’s a great feeling.
Your big inputs are MV, BC/Drag, and environment. These are the variables that don't change that much - at least compared to the wind which is changing every microsecond.
What is the BC you are using for your 198gr load (moving at 2900ish at MV)? Getting this correct is your first step. You can use Coefficient of Drag curves instead of BCs, but for 1 mile and this ballistic compound, a drag curve is more math than you need to worry about.
Next you need to get your environmentals correct... mainly, what the air density is. Most solvers use a model to estimate air density using pressure, temp, humidity and/or your elevation.
You can fine tune this solution with stuff like spin drift, coriolis efffect, and a few other minor variables. But the major variables are above and if these are correct, hits will follow.
Let me know the BC or Drag Curve you are using and I will have some comments (I helped Josh solve for the BC of this bullet, so I know quite a bit about it).
BC of these 198gr Flatlines are .838 (G1)
I had to cool the FPS down a tad bit. Flattened a few primers last time I went out. So it's around 2840fps now.
Other than a kestrel what else can I use to get environmental data?
@Awag1000
what powder and barrel length?
Also what twist rate?
2840fps is a slow MV for a 300WM and the Flatline. My 30" long action 308, 8.7 twist, moves them at 2770fps-ish (at 60*F) with 48ish grains of 2000MR.
Also, are you getting these bullets from Warner Tool or from Josh at PVA?
That G1 BC is for the bullet when it is moving at 2.5 mach (2850fps-ish). Your bullet is not going to be moving that speed for it ToF. To 1 mile, I think a better G1 is 0.812, or better yet, switch over to a G7 BC and use 0.408. I am using 0.408 G7 BC with hits out to 2100yds with that.
what powder and barrel length?
Also what twist rate?
2840fps is a slow MV for a 300WM and the Flatline. My 30" long action 308, 8.7 twist, moves them at 2770fps-ish (at 60*F) with 48ish grains of 2000MR.
Also, are you getting these bullets from Warner Tool or from Josh at PVA?
That G1 BC is for the bullet when it is moving at 2.5 mach (2850fps-ish). Your bullet is not going to be moving that speed for it ToF. To 1 mile, I think a better G1 is 0.812, or better yet, switch over to a G7 BC and use 0.408. I am using 0.408 G7 BC with hits out to 2100yds with that.
23.5" 1:9 5R
Hodgdon H1000
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Copy. OK, your MV looks good with that barrel length. Twist fine too.
So try my G7 BC and see if that helps get those bullets centered up on the vertical dimension.
Will do.
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