how to identify holes in ladder test

[dmax1800]

I'm going to be developing loads for 2 rifles in the very near future and for 1 rifle this spring. I'm going to use ladder tests at 200 yards to start with. It's my understanding that I should fire the complete ladder test and wait from 1 to 3 minutes between shots so that the barrel doesn't get too hot. I've done ladder tests in the past and have had trouble with shots overlapping each other, ie not moving continuously up with increasing powder. I would shoot 3 or 4 shots with colored bullet tips and then go identify them on the target. This would let the barrel cool down.

I don't have a spotting scope to keep track of each shot and I have a hard time identifying the close shots with my 4.5-14 rifle scope . I'm looking for ideas on how I can identify each different shot.

Thanks.

 

[crowsniper]

Set a camcorder close to the target and record the shots

 

[dmax1800]

Set a camcorder close to the target and record the shots

In addition to not having a spotting scope, I also don't have a camcorder.

 

[geargrinder]

I've heard that different color markers on the bullets will leave residue on the paper. Make a chart of the load v. color and have at it.

Can't hurt to try a few.

 

[farout]

I've done ladder tests in the past and have had trouble with shots overlapping each other, ie not moving continuously up with increasing powder.

Hey dmax,

I think this is actually what you are looking for in a ladder test anyway. So, eliminate the ones that are outside of that tiny cluster that you cannot identify and you will have the loads that are in the node.

I on the other hand have a camcorder that I can never find a use for. Now I have....lightbulb

 

[Mikecr]

You might consider one of these dealeos:
Amazon.com: Midland Consumer Radio XTC260VP3 High Definition 720p Wearable Action Camera with 2 Mounts (Black): Camera & Photo
Recording to 13-20min per GB of micro SD card. That's enough & under $100 total.

 

[rcairflr]

You simply take a large sheet of paper and put multiple targets on it. Don't shoot each round at the same target.

 

[jimbires]

here is a link to ladder testing . about half way down is a tanish color section that talks about color marking bullets . I think a trick to this is not getting color on the ogive , I think this is where I'm goofing up . I've tried to do this color marking but it never worked out for me . Jim


Long-Range Load Development

 

[Mike 338]

200 yards is probably to close to allow you to identify the separation or lack there-of. It's thought that 300 yds is bare minimum and more is better.

 

[varmintH8R]

200 yards is probably to close to allow you to identify the separation or lack there-of. It's thought that 300 yds is bare minimum and more is better.

+1, not much margin of error at 200.

 

[dmax1800]

Would it be a problem or not a good idea to shoot 4 (1 plain, 1 red, 1 blue and 1 green) and then go mark the holes on the target? Would the barrel cooling down between the groups of 4 be enough to invalidate the test??? I found out that my 270 shoots a lot better when the barrel is warm than when it's a cold bore.

These are hunting rifles, not bench rest rifles. So they may not be accurate enough to shoot at 300 yards for a ladder test. I may get too much spread just because of accuracy at 300 yards.

rcairflr, that is an idea to use 1 sheet with multiple targets. I think it would be easier to evaluate if all the bullet holes were together.

 

[varmintH8R]

These are hunting rifles, not bench rest rifles. So they may not be accurate enough to shoot at 300 yards for a ladder test. I may get too much spread just because of accuracy at 300 yards.

If this is the case, I would argue that you have the same issue at 200. Your ladder test is working to detect relatively minor POI changes at 200 yds to establish an accuracy node relative to charge weight. If the accuracy of the gun has more variation at 200yds than the difference in charge weights will produce, you are likely to not get a repeatable result.

You may look to just pick 4 charge weights (that you know are safe), shoot some groups to see what shoots best, and refine over time.

My 2C only

 

[varmintH8R]

Not sure what you are shooting, but here is an example:

A 7mm 168gr Berger VLD @ 2825fps will drop 2.7" at 200 yds (100yd zero)

Same bullet at 2600fps will drop 3.6" at 200 yds

So, at 200 yds -200 fps increases your drop less than 1". If your rifle is 1MOA, you have a 2" inherent variance at this range for any given charge weight. IMO It would take a lot of ladders to sort out the noise and get a strong idea of your true node.

 

[Mike 338]

If this is the case, I would argue that you have the same issue at 200. Your ladder test is working to detect relatively minor POI changes at 200 yds to establish an accuracy node relative to charge weight. If the accuracy of the gun has more variation at 200yds than the difference in charge weights will produce, you are likely to not get a repeatable result.

You may look to just pick 4 charge weights (that you know are safe), shoot some groups to see what shoots best, and refine over time.

My 2C only

That sounds right. For a ladder test to work, the rifle has to be intrinsically accurate with the components your using. You also need enough distance that as you work your way up in charge weight, there is a clear space of separation between the different charges until you find that sweet spot where everything is hitting in the same general vertical area.

If your rifle is throwing them all over the place at 300 yards or more, the ladder test maybe isn't the ticket for load development. Here's a different load development method that's been know to work well for hunting rifles. Use the menu bar on the left for more information.

OCW Overview - Dan Newberry's OCW Load Development System