Thread: Why plateaus in velocity graph

read up on Dan Newberry's Opitmum charge weight, and Chris Longs's optimal barrel time

OCW Overview - Dan Newberry's OCW Load Development System
Optimal Barrel Time Paper

velocity "usually" flattens out at the accurcy nodes...but not always so go figure!

1000yd tuning, positive compensation, ladder tests, ladders for seating depth...
So many theory's so little barrel life.

Originally Posted by sneeze

1000yd tuning, positive compensation, ladder tests, ladders for seating depth...
So many theory's so little barrel life.

Truth...

Do it this way, don’t do it this way, try it yourself. All I know it works most of the time quickly. The odd projectile or rifle takes a little more tweaking. At the end of the day everyone would arrive at the same load with the same rifle however you do it. This way is just the quickest, least hassle, least rounds and least barrel life used.

I had a guy come out to see me to do load development on a creedmore. 35 rounds later he had gone from 2350 FPS to 2500 FPS and was still at least 200 FPS off his target velocity. Like watching grass grow. Took about an hour and a half by the time he let the barrel cool between strings.

I have tried it. After shooting the first string I shot a second, the plateau from the first string wasnt there in the second. I could have shot the second string first, or third. It did give me an idea of where max might be but that's about all. I posted similar results here https://www.nzhuntingandshooting.co....38/index2.html
Iv Had a good look at barrel timing and that comes with its own set of issues. I ran some of my best loads through the theory and got noting but random results. Trying to use QL to determine the exit time is hopeless, its just computer modeling and there are to many variables to expect any consistent level of accuracy from it. That shows in the random outputs compared to real worl results as well eg fro my 243ai its right on the money but the 280ai its not within 150fps with any of the loads I tried.
The OCW I think works ok but its not far off a what Id call a stanard work up.
My opinion fwiw is these techniques are mostly smoke and mirrors that become accepted through a combination of confirmation bias and to small test samples.
But its little more than an opinion so ..

I have worked up loads for a lot of rifles over the years and find the Dan Newberry OCW quite helpful but experience usually lets me spot the load that's going to work in each rifle. It's a bit like when your hunting a new area and you move into a spot and it just screams an animal is here! I know this doesn't help someone who has done little load development but thats just how it is.

Sneeze, I saw your results. 1/2 grain is too much. You’ll never see flat nodes. .2 to .3 to get accurate node data. But what ever do it your way, I’ll do mine. If your going to shoot 3 shots at each you might aswell shoot groups.

The example from the other thread is a large 7mm. .5gr is smaller than your .3 in a creedmore in percentage terms. When I tried it I used .2 in 222 rem. I’m not saying there is no flat spot but statistically you can’t find it from one shot per charge. Think about the variation you get from one three shot group. It can easily be 30fps. You don’t know if your single shot is the high value low or close to the average. The high from one followed by a low from the next and it will look flat but reverse that and it will show a the opposite. In order for the theory to work every single shot would need to be close to the average. It won’t be so it becomes random.
But yes by all means we are free to believe in anything we want .or not. If it’s working for you and is repeatable the 👍