Ladder testing

[SlvrDragon50]

I just loaded my first 40 rounds of 223. I used IMR 8208XBR w/ Hornady 55gr FMJBT bullets. I loaded 4 different charges at 24.2gr, 24.5gr, 24.8gr, and 25.1gr. I expect the 25.1gr to perform the best based upon reading others load data, but I have a little bit of overhead at 25.3gr max. I did load slightly under the recommended COL at 2.1975" vs 2.2".

 

My question is how do I best test this ladder? Normally with my pistol loads, I could just chrono and then shoot groups if I wanted to (I usually just chrono.. and freehand groups). My problem with shooting out to 100 yards is that I am a new shooter, and I am 99% sure I'm not gonna be able to shoot a good group even if given the best ammo in the world. I shoot with a red dot. Would it be okay to shoot groups at a closer distance? 

[DesertTortoise]

My understanding with the ladder test is to use a single round each for each powder charge in order to find a sweet spot where the velocity is consistent despite marginal changes in the amount of powder used. You should see a more or less vertical string with (probably) the lowest charge round on the bottom and the highest charge on top. 

 

The accuracy guys use this test to speed up load development and determine if the bullet and powder are suitable. The next step is to test different seating depths by firing groups.

 

Im not sure about distance to the target and if 25 or 50 yards will show enough difference to get a result. Maybe a more serious rifle hand loader can chime in on that.

 

If if it were me in your circumstances I’d pick a distance I was comfortable with and shoot 2 groups of 5 rounds each for every load you made up. Testing loads for accuracy with a rifle can be frustrating, especially when you aren’t sure about all the variables. Even with a rest, shooting tiny little groups on demand isn’t easy. I have one rifle (243 bolt action) that starts throwing flyers after the barrel heats up and another (ar 15) that hates 55 grain bullets. And my 6.8 SPC Went from a 3 inch group to 1 inch at 100 yards when I seated the bullet 0.010 shorter. Frustrating. 

 

If you are just looking to roll your own instead of buying ammo, bring some factory ammo along and shoot that to compare. If your reloads get a similar result, I’d call that a win. I hope that helps!

 

Remember to look for pressure signs before moving up to the next charge weight. I sometimes get distracted with the semi auto and forget to pick it up and look.

[SlvrDragon50]

Okay, I don't think I'll be able to chrono my loads before I go on a short vacation, but I will return with some chrono stats and proceed from there. I picked my 9mm load based on meeting minor PF and minimal SD so it seems like a similar process.

[Old3GNR]

I've been reloading .223 for many years but just now am planning a ladder test.  You can chrono your loads without shooting for accuracy, just look for similar velocity within a group of powder charges.  Once you've selected a charge shoot at longer range.  A red dot will not be accurate enough and you should shoot at closer to 300 yards.  For .223, I'd vary the powder charge by .2 gr

[SlvrDragon50]

I've finally got around to chronoing my loads.

 

24.2gr - Avg 2749 fps - STD 30 - 151.2 PF

24.5gr - Avg 2771 fps - STD 27 - 152.41 PF

24.8gr - Avg 2846 fps - STD 20 - 156.53 PF

25.1gr - Avg 2872 fps - STD 17 - 157.96 PF

 

I'm not sure why there's such a big jump in fps between 24.5 and 24.8gr. COAL was the same for all four loads. Anyways, how should I proceed from here. Just group them all and pick based on best grouping? I didn't notice any real difference in recoil, and none of them had issues cycling. All four are above minimum USPSA 3 gun power factor.

[uewpew]

consistent muzzle velocities will result in consistent bullet drop (for long shots).  If the 25.1 or 24.8 loads group less than 2MOA i'd go with one of them.

[SlvrDragon50]

That's what I was thinking as well. I suspect there might have been improvement in reloading technique as well, but I'm not expecting super great STD since I'm not sorting by stamp and bulk trimming with a Tri Way trimmer.

[SlvrDragon50]

Finally grouped the loads. Not what I expected with the 24.5gr grouping the best followed by 24.2gr. I am a little unsure what happened on the higher loads. I don’t think this target worked well for a 50yd shot through an unmagnified optic. I guess it’s possible I wasn’t aiming in the same spot for the 24.8? It has a lot of left right spread. It was very windy today but I don’t think it should matter at 50 yards. I know when I shot the 24.8gr the optic was disturbed a lot more after firing and I had to reset the aim so maybe that explains why the POI shifted so much.

I think realistically all of these would work for 3 gun. I will probably go with the 24.5gr.


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[12glocks]

I would mount an optic, maybe even off another rifle on the rifle temporarily for accuracy testing at 100 and then 200.  When you find your most accurate load then you can run your dot again knowing definatively what is the accurate load.

 

Also, 55 grain FMJ's tend to have underwhelming accuracy for the majority of people.  I would suggest the 68/69 or 75/77 grain bullets.  They are markedly more accurate, as a rule.  I have had outstanding luck with 8208.

[SlvrDragon50]

Just now, 12glocks said:

I would mount an optic, maybe even off another rifle on the rifle temporarily for accuracy testing at 100 and then 200.  When you find your most accurate load then you can run your dot again knowing definatively what is the accurate load.

 

Also, 55 grain FMJ's tend to have underwhelming accuracy for the majority of people.  I would suggest the 68/69 or 75/77 grain bullets.  They are markedly more accurate, as a rule.  I have had outstanding luck with 8208.

Unfortunately I have no magnified optics. Developing these loads is one of the reasons why I'm considering buying a LVPO. I went with the 55gr since we pretty much never shoot beyond 100 yards. We do mostly 25-50 yd shots on 1/2 size USPSA targets. I think these should all group within the A zone on a half size..

[12glocks]

4 minutes ago, SlvrDragon50 said:

Unfortunately I have no magnified optics. Developing these loads is one of the reasons why I'm considering buying a LVPO. I went with the 55gr since we pretty much never shoot beyond 100 yards. We do mostly 25-50 yd shots on 1/2 size USPSA targets. I think these should all group within the A zone on a half size..

If those are your parameters just shoot any load.  Maybe you will like the way a minimum load feels or maybe the comp will work better with more gas from a hotter load.  

[Hi-Power Jack]

7 minutes ago, SlvrDragon50 said:

we never shoot beyond 100 yards. We do mostly 25-50 yd shots on 1/2 size USPSA targets.

 

Any of those 50 yard groups is fine for the type shooting you're doing.

 

And, so is the red dot.

 

If you start shooting more at 100+ yards, then you should move your

target back to at least the 100 yard line.     

[PhillySoldier]

Am I the only one that doesn’t think highly of “Ladder Testing”. Granite I use the term incorrectly often to describe any type of type of testing that that has incremental changes in it.  But in the terms of testing 10 rounds each at different charge weights looking for some supposed “flat spot” in velocity

 

First of all single round of anything I think is pretty useless. You cant confirm your results or even have anything to compare the results too. The more data you have the more you can compare the results.

 

As for the magical “flat spot/node”; lets face it if you are increasing your charge weights and the pressure you should also see an increase in velocity. So I fail to see what supposed “flat spot/node” everyone is looking for. There should always be a difference in velocity between differing charge weights. Just my thoughts but I would find it to be more of a problem if differing charge weights had the same velocities.

 

If we shot and chronoed 10 rounds of the exact same charge weight, how many will be the exact same velocity? We would still have seen a varying SD/ES let alone comparing varying charge weights.

 

And none of this shows and compares the actual results of the bullets accuracy or how tight the shot groups might be. Just that you can get away with some variance in powder weights and supposedly keep a low SD in velocity

 

[Jakobi]

On 7/31/2018 at 5:38 AM, PhillySoldier said:

Am I the only one that doesn’t think highly of “Ladder Testing”. Granite I use the term incorrectly often to describe any type of type of testing that that has incremental changes in it.  But in the terms of testing 10 rounds each at different charge weights looking for some supposed “flat spot” in velocity

 

First of all single round of anything I think is pretty useless. You cant confirm your results or even have anything to compare the results too. The more data you have the more you can compare the results.

 

As for the magical “flat spot/node”; lets face it if you are increasing your charge weights and the pressure you should also see an increase in velocity. So I fail to see what supposed “flat spot/node” everyone is looking for. There should always be a difference in velocity between differing charge weights. Just my thoughts but I would find it to be more of a problem if differing charge weights had the same velocities.

 

If we shot and chronoed 10 rounds of the exact same charge weight, how many will be the exact same velocity? We would still have seen a varying SD/ES let alone comparing varying charge weights.

 

And none of this shows and compares the actual results of the bullets accuracy or how tight the shot groups might be. Just that you can get away with some variance in powder weights and supposedly keep a low SD in velocity

 

 

Go read this for a good explanation of ladder loading and the mechanics of what it is accomplishing.

 

I shoot at 300 yards/meters when I'm ladder testing.

Edited August 22, 2018 by Jakobi

[Dwbsig]

There is two different types of ladder tests that I have used some may call them something different.

1. Load five each of different powder charges and shoot five shot groups at 100 yds looking for the best group.

     After finding the best charge work the oal the find the most accurate oal.

2. Load one powder charge each about three tenths of a gain each for 223 and shot at three hundred yards.

     That this point you are looking for three or four loads that has grouped fairly close together.

      That will be the sweet spot for that powder and the hormontics of your barrel.

[T-Free]

On 8/22/2018 at 2:25 PM, Dwbsig said:

There is two different types of ladder tests that I have used some may call them something different.

1. Load five each of different powder charges and shoot five shot groups at 100 yds looking for the best group.

     After finding the best charge work the oal the find the most accurate oal.

2. Load one powder charge each about three tenths of a gain each for 223 and shot at three hundred yards.

     That this point you are looking for three or four loads that has grouped fairly close together.

      That will be the sweet spot for that powder and the hormontics of your barrel.

I use the #2 method and feel its the quickest way to work up a new load. If the max is 73.5  I will load up 7-8 rounds in .5 increments to max. Ex- 70,70.5,71,71.5,72,72.5,73,73.5 all loaded to the same length. I fire this at 100 yards but 2-300 is usually recommended. Somewere in that group of different powder charges I will get 3-4 bullets in a nice group, say 71g (2,790fps) to 72.5 (2,850fps). If i dont get a good group i try another powder but with that data I will choose 71.8 and start playing with seating depth.

[gmantwo]

I’m just curious as to why you would spend so much time trying to find the best possible combination of components for a dot/short distance usage? If you’re hunting, the accuracies displayed are all more than adequate for any distance/game you would use a  red dot sight on. If you’re shooting steel, same thing. Paper punching at any distance pretty much precludes the use of a magnified optic to need any tighter groups, so.....?

 I understand it’s your time and I would not try to tell you how to use it, but I would use it to put more rounds down range, lol

[Jakobi]

Ladder testing with method 2 (described above) and a red dot or irons is probably not going to be that useful (at least in my experience as the aiming device is too imprecise given what you're trying to accomplish). I would use the first method to find a load that gave acceptable groups and would probably be happy with 2 MOA (depending on dot size). I've seen rifles easily go from 4 to 2 MOA shooting with irons or a dot just based on the ammo/load.

Edited December 18, 2018 by Jakobi

[Dwbsig]

1 hour ago, Jakobi said:

Ladder testing with method 2 (described above) and a red dot or irons is probably not going to be that useful (at least in my experience as the aiming device is too imprecise given what you're trying to accomplish). I would use the first method to find a load that gave acceptable groups and would probably be happy with 2 MOA (depending on dot size). I've seen rifles easily go from 4 to 2 MOA shooting with irons or a dot just based on the ammo/load.

Yeah the #2 method is meant for precision scoped rifles.