Interpreting Velocity Data Points for Load Development

[Unknown Munitions]

We get asked often about load development and what it all means. Terms like optimal charge weight, ladder test, barrel harmonics, bullet jump, Base to Ogive, Cartridge overall length, etc. often cloud this space with technical terminology not often understood by most shooters just trying to do their best in the field and in their loading room. We take a unique approach to load development here at Unknown Munitions. We have created a visual representation of velocity data points to help our customers understand what is happening and remove some of the mystery behind the process. Below you will see data fed back to us from a ladder test ammunition box sent to one of our customers, he shot this test himself and emailed velocity numbers back. You'll notice a unique node wave form across .9 grain increments. But what do you do with this data? Let's use this thread to discuss opinions and hopefully debunk some myths and mysteries behind this load development process.

 

[BuckSnort]

Load #5 is money...

 

[Unknown Munitions]

Load #5 is money...

Heck yeah, that’s where we settled. Now sending him a jump test to get it tightened up


Sent from my iPhone using Tapatalk

 

[Muley Buck]

Did he shoot paper while doing this? If so, what did the groups look like? Especially load #5?

 

[DRUSS]

So how much does this service costs? Having you load up a ladder and jump test for a guy to try out? I am getting ready to start loading my 300 Rum with 230 Berger or my 28 Nosler with 195 Berger? Could PM if you prefer also?

 

[Unknown Munitions]

Did he shoot paper while doing this? If so, what did the groups look like? Especially load #5?

I'm sure he shot paper, but I don't have any specs on group size from him.

 

[Unknown Munitions]

So how much does this service costs? Having you load up a ladder and jump test for a guy to try out? I am getting ready to start loading my 300 Rum with 230 Berger or my 28 Nosler with 195 Berger? Could PM if you prefer also?

We have both 300 RUM and 28 Nosler in stock along with your bullet selections. The ladder test charge is $39 additional when you purchase a box of ammunition. We can set the test up however you'd like to any spec. Give me a call anytime time to discuss.

 

[DRUSS]

Thanks, I will give you a call this week.

 

[Muley Buck]

I'm sure he shot paper, but I don't have any specs on group size from him.

Gotcha. I was just curious to see what they were printing at that stage of the development process.

 

[HuntnPack]

#5 ....That is some;
Data Driven Performance Ammunition
Right there.

 

[Brendan]

Going to bump this thread because I'm working at home, ranges closed, and a hunting trip postponed...

Looking at your graph above, I'm assuming that at this stage you're just looking at minimizing ES? So - customer shoots all your test rounds through a chrono, logs speeds, calculates the minimal ES.

Next step - play with bullet jump to minimize group size? And, if you can't get it where you want, try a different velocity node? (Next up looks to be load 8?)

 

[Unknown Munitions]

Going to bump this thread because I'm working at home, ranges closed, and a hunting trip postponed...

Looking at your graph above, I'm assuming that at this stage you're just looking at minimizing ES? So - customer shoots all your test rounds through a chrono, logs speeds, calculates the minimal ES.

Next step - play with bullet jump to minimize group size? And, if you can't get it where you want, try a different velocity node? (Next up looks to be load 8?)

Yes sir, that’s exactly right

 

[Low_Sky]

@Unknown Munitions , if a barrel speeds up or slows down in the first few hundred rounds of life, do these nodes tend to change during that process? Say you and the customer settle on load #5, can you count on having that low ES at that charge weight through any changes in the barrel's speed as it breaks in?

I'm a less-than-1-year reloading starting over with a new barrel in my Tikka, so this topic was timely and really helpful for me. Thanks for sharing your method.

 

[HuntnPack]

Tagging for response to Low_Sky

 

[Cahunter805]

@Unknown Munitions , if a barrel speeds up or slows down in the first few hundred rounds of life, do these nodes tend to change during that process? Say you and the customer settle on load #5, can you count on having that low ES at that charge weight through any changes in the barrel's speed as it breaks in?

I'm a less-than-1-year reloading starting over with a new barrel in my Tikka, so this topic was timely and really helpful for me. Thanks for sharing your method.

Normally a barrel will settle in around 100 rounds or so. Most will actually speed up also. I normally get a decent powder charge and then test for seating depth while I try to get to 100 rounds. Once 100 rounds is reached I fine tune my powder and seating depth to find my rifles node and then validate drops/velocity.

 

[ericwh]

Since it looks like you are initially only chasing flat spots in velocity and/or low SD/ES, what are your thoughts on the ladder tests that chart the height of impact, which charges impact together, and/or vertical spread and usually involve discussions on barrel whip and so on?

 

[Unknown Munitions]

@Unknown Munitions , if a barrel speeds up or slows down in the first few hundred rounds of life, do these nodes tend to change during that process? Say you and the customer settle on load #5, can you count on having that low ES at that charge weight through any changes in the barrel's speed as it breaks in?

I'm a less-than-1-year reloading starting over with a new barrel in my Tikka, so this topic was timely and really helpful for me. Thanks for sharing your method.

You definitely want to make sure your barrel is done picking up speed before starting load development!

 

[Unknown Munitions]

Since it looks like you are initially only chasing flat spots in velocity and/or low SD/ES, what are your thoughts on the ladder tests that chart the height of impact, which charges impact together, and/or vertical spread and usually involve discussions on barrel whip and so on?

I think barrel harmonics and positive compensation are fascinating topics. Chasing the upward momentum of the sinusoidal wave pattern to allow faster bullets to exit when the barrel is straight on and slower bullets to exit above those only to have them meet up down range is awesome!

 

[Muley Buck]

I think barrel harmonics and positive compensation are fascinating topics. Chasing the upward momentum of the sinusoidal wave pattern to allow faster bullets to exit when the barrel is straight on and slower bullets to exit above those only to have them meet up down range is awesome!

That's awesome! I never thought about that before.

Physics is a helluva thing!

 

[menhaden_man]

We get asked often about load development and what it all means. Terms like optimal charge weight, ladder test, barrel harmonics, bullet jump, Base to Ogive, Cartridge overall length, etc. often cloud this space with technical terminology not often understood by most shooters just trying to do their best in the field and in their loading room. We take a unique approach to load development here at Unknown Munitions. We have created a visual representation of velocity data points to help our customers understand what is happening and remove some of the mystery behind the process. Below you will see data fed back to us from a ladder test ammunition box sent to one of our customers, he shot this test himself and emailed velocity numbers back. You'll notice a unique node wave form across .9 grain increments. But what do you do with this data? Let's use this thread to discuss opinions and hopefully debunk some myths and mysteries behind this load development process.
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@Unknown Munitions , do you have any advice on tradeoffs between ES, velocity, and group size?