SD ??
- Thread starter chet
- Start date
you can try switching primers, that can sometimes help tighten the ES
But first thing to ask is what will be the max range you will be shooting at ? Using the BC of the 140 ELD and 2750 FPS as a high and 2700 FPS as a low the POI would only be 1.2 lower at 500 but around 14 inches lower at 1000.
Unless you are shooting 800 and 1000 I would not sweat it
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The chronograph you use makes a big difference too. I had a cheap one and it gave me fits with extreme spread. Numbers just didn’t make sense for the amount of effort and attention to detail I was putting in. Bought a magnetospeed and shot over a Labradar and the numbers make more sense. Group is the most important. Don’t get too hung up on the numbers. I watched one of my friends shoot a 200-18x at 600 yards on an F-class target and the extreme spread was around 23fps for 20 shots. Trying to chase numbers with any of them will take years off your life.
If you are testing that many bullets, I don't know how you can gather any hard data. Pick one you think you may like and make it work.
If bullets leave the muzzle axis on its upswing at the right place, slower ones will leave at a higher angle from the LOS compensating for their greater drop at target range.
Weights on the muzzle adjust back and forth to "tune" the muzzle axis ertical vibration frequency to make that happen. Groups at half range will have greater angular spreads so the tuner can be adjusted for best drop compensation at that range.
Weights on the muzzle adjust back and forth to "tune" the muzzle axis ertical vibration frequency to make that happen. Groups at half range will have greater angular spreads so the tuner can be adjusted for best drop compensation at that range.
Dusty Stevens
Shiner
The target matters unless youre entering into a chronograph match (which i think is the end goal around here sometimes)
What Dusty said!
Find your load at 100 yds. Go test it at the max distance you plan to shoot with it. The target is the final arbiter. I use a chronograph primarily to watch for pressure since speed = pressure. This may be blasphemy to some, but you can get too technical in your process. When my chronograph and target don't agree, I will always trust my target then test at range. There have been many examples on this forum of loads that shot well at range that had larger than expected SD for the way they performed. When reading some of the newer publications on shooting/reloading you have to remember that much of what you read is theory. Knowledge of how things work based on theory can be good, but is not necessary. Many good loads were developed before chronographs became affordable for the average shooter.
Find your load at 100 yds. Go test it at the max distance you plan to shoot with it. The target is the final arbiter. I use a chronograph primarily to watch for pressure since speed = pressure. This may be blasphemy to some, but you can get too technical in your process. When my chronograph and target don't agree, I will always trust my target then test at range. There have been many examples on this forum of loads that shot well at range that had larger than expected SD for the way they performed. When reading some of the newer publications on shooting/reloading you have to remember that much of what you read is theory. Knowledge of how things work based on theory can be good, but is not necessary. Many good loads were developed before chronographs became affordable for the average shooter.
I'd tweak a few things first, neck tension, seat depths etc.. But if you want to switch powders, RL 16 the closest to H4350. RL 17(good) but different beast.
Please explain, "Groups at half range will have greater angular spreads so the tuner can be adjusted for best drop compensation at that range".
I think hes saying that half way to the convergence point (target) will be the largest divergence /the highest point has the largest gap between fast and slow.
Adjusting the tuner can move harmonics so that the convergence point is where you want it to be instead of just the distance it was previously set up for.
Adjusting the tuner can move harmonics so that the convergence point is where you want it to be instead of just the distance it was previously set up for.
Post 12 had the answer.
People have been observing this since the early 1900's or sooner.
http://www.geoffrey-kolbe.com/articles/rimfire_accuracy/tuning_a_barrel.htm
Chech out the link to Al Harral's website then click on tuners' for details.
I think hes saying that half way to the convergence point (target) will be the largest divergence /the highest point has the largest gap between fast and slow. Thanks, I understand positive compensation, it was just not clear that was what Bart B. was referring too. All is well.
Adjusting the tuner can move harmonics so that the convergence point is where you want it to be instead of just the distance it was previously set up for.
I understand "positive compensation". It was not clear to me that was what you were saying. All is well.
what croney?
how are your groups?
how are you weighing your powder?
have you played with seating depth?
i don't even use a cronograph during load development. run a OCW or ladder test to find a charge weight and then play with seating depth. let the target tell the tale.
after load development then i see what my magnetospeed tells me. usually i am pleasantly surprised. that data can then be used in a ballistic calculator
what i have found to reduce SD's is accurate powder charges and playing with seating depth.
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