223 Ladder Test

[Ajwilly96]

Today I shot a two shot ladder test from my 223 using N140 90gr Berger and CCI-450. These were my charge weights and velocity. I started with a clean barrel and fired five fouling shots.

23.3- 2644,2644
23.6- 2677,2684
23.9- 2708, 2712
24.2- 2738, 2735
24.5- 2774, 2783
24.8- 2788, 2791
25.1- 2849, 2821
25.4- 2838, 2848

Based on these charges and velocities I decided to load 25rds of 24.6gr all the same seating depth. I return and began to fire. Once I was finished. I had velocity ranging from 2788 to 2851.

I was pretty shocked by these results being that the velocity changes were so extreme. Has anyone ever experienced this before? I was not letting my barrel get super hot, it was not a gradual increase in velocity they were pretty sporadic.

I’m not really sure where to go from here.

The grouping at 100 yards is good but I plan to shoot at 1000, so I want to get my velocity under control

 

[Evan]

You can throw the kitchen sink at load prep and do better, but ultimately the 223 just never seems to get tight ES numbers like the 308 or BR cases. By tuning at distance, you may find you can get good grouping despite larger ES numbers.

What type of brass are you using and what have you done to prep/sort it so far?

 

[RegionRat]

Here is what that data looks like. I'm not sure what to do with the screenshot data?



I agree with @Evan that 223 is one of the most difficult cartridges to get a quiet velocity stat I know of.

That said, I don't need to lecture you about how difficult it would be to say anything at all based on these velocity numbers without the target data out at a fair distance to go along with them. You just can't make a decision based on two shot samples of these powder steps.

That chart would say the 25.1 step was bad, but if we had more shots on all of them, it could turn around and be the best for all we know.

I don't want to say ignore the chronograph, but I guess I am saying now that you have seen that data I would ignore it and focus on target data at a distance where the trajectory can tell you the story.

ETA: I don't think an SD of 16.2 is terrible for a starting point. I updated the chart to include the extra shots at 24.6 grains. If you now imagine the same amount of data fro all those other points, you can understand how it is nearly impossible to know anything from a "velocity ladder test" that uses two or three points per step.



That ES of 63 won't cut it at 1000, but would probably clean up with a little more work.

 

[Dave Zander]

This is why I tried N150 with the 90 g Berger. 24 grains with .010” jam really tightened up the extreme spread. On 6 shots I had 11 FPS. Spread. Velocity wasn’t great at 2740 but it grouped well. I was previously running N140. I have a 6.5 twist.

 

[markm87]

The best ES reducer I've had for 223 is the Wolf SRM primers. My new production CCI 41s which are the same as 450s give me the absolute worst SDs and ESs ever.

If it were me, I'd try a primer substitution.

 

[CharlieNC]

Did you shoot these on a target too? It should exhibit a charge weight range where the vertical poi varies little to none.

 

[Dave Zander]

The best ES reducer I've had for 223 is the Wolf SRM primers. My new production CCI 41s which are the same as 450s give me the absolute worst SDs and ESs ever.

If it were me, I'd try a primer substitution.

450’s sucked for me also
Federal 205 and 205 m gave better results. Didn’t seem to matter which Federal I used.

 

[chop house]

You can throw the kitchen sink at load prep and do better, but ultimately the 223 just never seems to get tight ES numbers like the 308 or BR cases. By tuning at distance, you may find you can get good grouping despite larger ES numbers.

What type of brass are you using and what have you done to prep/sort it so far?

i found this out also last summer. i asked around and that was the general consensus.

 

[chop house]

The best ES reducer I've had for 223 is the Wolf SRM primers. My new production CCI 41s which are the same as 450s give me the absolute worst SDs and ESs ever.

If it were me, I'd try a primer substitution.

thank you for the tip. i was pretty stuck on the 450's when i was messing around with this same issue

 

[Ajwilly96]

You can throw the kitchen sink at load prep and do better, but ultimately the 223 just never seems to get tight ES numbers like the 308 or BR cases. By tuning at distance, you may find you can get good grouping despite larger ES numbers.

What type of brass are you using and what have you done to prep/sort it so far?

Lapua once fired, skim turned necks, AMP annealed,

 

[Ajwilly96]

This is why I tried N150 with the 90 g Berger. 24 grains with .010” jam really tightened up the extreme spread. On 6 shots I had 11 FPS. Spread. Velocity wasn’t great at 2740 but it grouped well. I was previously running N140. I have a 6.5 twist.

I might have to try jam, right now they are .010 off. Trying to keep up with you and Randy at Rayners haha

 

[Ajwilly96]

Did you shoot these on a target too? It should exhibit a charge weight range where the vertical poi varies little to none.

I was messing with my tuner while I was shooting the 25 rounds that I posted. This was the 4 shot once I found my setting

 

[Evan]

Lapua once fired, skim turned necks, AMP annealed,

It’s laborious, but you can sort them by water capacity, and then uniforming the primer pockets will usually get you all you can get from the brass. As mentioned, I found jamming to help reduce vertical considerably at 1000yds. And then pressure. Hot loads that trash the brass do seem to shoot better, sadly.

 

[Evan]

Next question: is this on a known-good action? The firing system on rifles can be all over the place in quality, even on customs. If it has produced exceptional accuracy with a different barrel, then that helps narrow it down. Otherwise you should start checking firing pin fall, consistency of sound when you dry fire (diagnose pin drag/inadequately supported pin), etc. to ensure you don’t chase your tail on loading when the gun has an issue.

 

[Cfshooter]

Sounds pretty hot, what length barrel? I am assuming bolt gun? How many rounds down barrel? Something seems off.

 

[Ajwilly96]

Next question: is this on a known-good action? The firing system on rifles can be all over the place in quality, even on customs. If it has produced exceptional accuracy with a different barrel, then that helps narrow it down. Otherwise you should start checking firing pin fall, consistency of sound when you dry fire (diagnose pin drag/inadequately supported pin), etc. to ensure you don’t chase your tail on loading when the gun has an issue.

Brand new F-Class panda

 

[Ajwilly96]

Sounds pretty hot, what length barrel? I am assuming bolt gun? How many rounds down barrel? Something seems off.

30in barrel, bolt action, 141 rounds now

 

[Cfshooter]

30in barrel, bolt action, 141 rounds now

Could not have settled in yet. All same lot of brass? Prepped at same time?

 

[Ajwilly96]

Could not have settled in yet. All same lot of brass? Prepped at same time?

Yes

 

[Ned Ludd]

I don't think these results seem "off" at all. This is typical behavior for a .223 with heavies. Everything has to be "just so" and even then, 20-30+ fps ES values for 5 shots is typical. I would be very cautious about running charges of 25+ gr of N140 under a 90 VLD. Brass life already tends to be pretty poor in .223 Rem loads such as these. No need to make it worse for just a few fps more velocity. Once all the brass has been fire-formed, testing different primers and sorting cases by water volume (laborious), or by case weight as a surrogate for case volume (much easier, but less accurate), may help lower the ES/SD values. Finally, consistent/uniform neck tension is a necessity.