Finding "Nodes" on your rifle

[dariof]

How do you guys go about finding the nodes on your rifle, and how do you adjust for them when reloading.

I understand what a node is, but have no idea how to locate them.

 

[Darkside-Six]

How do you guys go about finding the nodes on your rifle, and how do you adjust for them when reloading.

I understand what a node is, but have no idea how to locate them.

There are to different ways of doing this.

Either ladder testing
Long-Range Load Development

or OCW (Optimal Charge weight)
OCW Overview - Dan Newberry's OCW Load Development System

 

[atlsniper6.5]

I perform a ladder test. Zero the rifle at 100 and put a large target out at 400-600 yards. Load the charges that you want to test from .2 to .5 grains apart. Fire 3-5 shots of each and note where they land on the target. Some will result in a vertical difference on the target. Some will group together. The ones that group together are your accuracy nodes.

 

[Sniper Uncle]

There is another option for predicting nodes

Optimal Barrel Time Paper

If you have a version of QuickLoad, a computer program which calculates internal ballistics for different powders, etc, this method seems to work well. I have used and am using it for getting close on load info for my rifles before I reach the range.

 

[dariof]

There is another option for predicting nodes

Optimal Barrel Time Paper

If you have a version of QuickLoad, a computer program which calculates internal ballistics for different powders, etc, this method seems to work well. I have used and am using it for getting close on load info for my rifles before I reach the range.

I've been told I should buy QuickLoad. I've been on their web site. I may just get the program.

 

[TwoGun]

http://precisionrifle.files.wordpress.com/2012/07/incremental-load-development-method.pdf

You kind of need to know your maximum load and work backwards and you need a chronograph. Max. load -.2gr to -.5gr increments backwards for 20 shots. You'll probably have 2 nodes in those 20 shots, 3 to 4 rounds with small variance in velocity across different charges. The nodes will also be closer to or at your x-axis which means the barrel is somewhat at rest at the 6 or 12 o'clock position as the bullet leaves the barrel.

X-axis consistency over elevation and consistent velocity over a small variance in powder charge is the ticket.

You should be able to find the nodes in 20 shots with a decent chronograph and at least a 300 yard range.

 

[rcamuglia]

This is the best...

Ladder testing at 1k- Detailed article and video - Page 3 - Long Range Hunting Online Magazine

 

[atlsniper6.5]

http://precisionrifle.files.wordpress.com/2012/07/incremental-load-development-method.pdf

You kind of need to know your maximum load and work backwards and you need a chronograph. Max. load -.2gr to -.5gr increments backwards for 20 shots. You'll probably have 2 nodes in those 20 shots, 3 to 4 rounds with small variance in velocity across different charges. The nodes will also be closer to or at your x-axis which means the barrel is somewhat at rest at the 6 or 12 o'clock position as the bullet leaves the barrel.

X-axis consistency over elevation and consistent velocity over a small variance in powder charge is the ticket.

You should be able to find the nodes in 20 shots with a decent chronograph and at least a 300 yard range.

It is worth mentioning that with a custom built rifle, 300 probably won't be far enough. A lot of them still keyhole at that range. Excellent advice on the working backwards. I am going to have to give that a shot next time out.

 

[rcamuglia]

It is worth mentioning that with a custom built rifle, 300 probably won't be far enough. A lot of them still keyhole at that range. Excellent advice on the working backwards. I am going to have to give that a shot next time out.

Keyhole?

 

[atlsniper6.5]

Keyhole?

LOL - slang for very tight group.

 

[Sniper Uncle]

Keyhole?

LOL - slang for very tight group.

Not to nit-pick, but Brian Litz uses the term "keyhole" in his book to refer to a tumbling bullet, making an oblong hole or keyhole. That is probably the source of the confusion....

 

[atlsniper6.5]

Not to nit-pick, but Brian Litz uses the term "keyhole" in his book to refer to a tumbling bullet, making an oblong hole or keyhole. That is probably the source of the confusion....

Good to know... I will be more mindful of my range slang in the future

 

[Darkside-Six]

I actually do both a ladder test and an OCW test when narrowing down my nodes. I start first with my ladder test and fire 1 string from low to high in .5 grain increments. I'll usually get 3-4 shots that group nicely. When I find my range....say 42-45 grains then I will load up in .3 grain increments and run an OCW test.

For me, that is the best way as I do not necessarily look for the best grouping but the best shots on center. From there I will experiment with seating depth.

 

[Punisher29073]

I do the ladder test at 300yds in .3 gr increments, usually loading 2-3 different powders and 2-3 different bullets creating 6-7 ladder tests to run at the same time. Once this is I find the 2 shots on each target with the least vertical disparity between them and load 5 rds each in .1 gr increments creating 20 rounds for each combo that looks promising. I then go shoot these for group size at 100yds. Taking the best of these I start playing with seating depth and tune it shooting groups at different depths in .005"s increments. That is what has worked best for me.

Ryan

 

[RonHam]

Good to know... I will be more mindful of my range slang in the future

For the most part everyone recognizes "keyholeing: as a tumbling bullet, now I've heard of tight groups referred to as bug holes before so maybe a misheard term?

 

[atlsniper6.5]

For the most part everyone recognizes "keyholeing: as a tumbling bullet, now I've heard of tight groups referred to as bug holes before so maybe a misheard term?

I probably heard someone use it incorrectly one time and it stuck.


Sent from my iPhone using Tapatalk

 

[samnev]

Since I like to find nodes on the lower end of the velocity range if possible I start near the low end with various powders and projo's and increase each load by 0.2 grains. It's tedious but pays off in the long run.