Chronograph Results with W231

[shortround451]

After posting last night asking what W231 loads everyone was using with 38 Spl I was able to chronograph my loads today. I got some interesting results. The loads were fired from a 3" Model 65. I fired two five round strings with each powder charge and bullet combination. Cases were mixed, both nickel plated and brass, and have been fired numerous times. :

4.2 grains W231 with Hardcast 158gr LSWC
1st string- 681 avg.FPS, ES- 125, SD- 45, High/Low- 734/608
2nd string-701 avg. FPS, ES-93, SD-38, High/Low- 749/655

3.9 grains W231 with Hardcast 158gr LSWC
1st string- 707 avg. FPS, ES- 24, SD-10, High/Low- 718/694
2nd string- 712 avg. fps, ES-29, SD-11, High/Low-724/694

4.2 grains W231 with Hardcast 148gr BBWC
1st string- 785 avg. FPS, ES-49, SD-21, High/Low- 807/757
2ns string- 795 avg. FPS, ES-27, SD-10, High/Low- 807/780

3.9 grains W231 with Hardcast 148gr BBWC
1st string- 772 avg. FPS, ES-24, SD-9., High/Low- 780/755
2nd string- 784 avg. FPS, ES-30, SD-16, High/Low- 803/773- This was a 3 round string as I ran out of ammo.

I am a little confused with the numbers from the 4.2gr/ 158 SWC load. The ES and SD were a little extreme and the average velocity was lower than the lighter load. My experience has shown that a high or low SD don't always show how accurate the load will be but I'm not sure what is going on with this load. The other numbers for the rest were about what I expected. I didn't shoot any groups but all loads shot well and seemed to shoot to point of aim.
I'm planning to load up some more and repeat this to see if the numbers hold up, and check accuracy, but in the meantime lets hear what ya'll think.

 

[Fkimble]

From the numbers, it looks like you may have had one very low reading. If you threw out the lowest reading on the 4.2 1st string, what would the average be?

 

[Rule3]

Two things.

How did you measure your powder charge. Was each individual charge weighed?

Also, to have a statistically valid sample you need more than 5 samples. 10 is a minimum. With only 5, a small difference in one charge can skew the whole results by a lot.

To be really consistent, the brass should all be the same.

 

[Wheelgunner840]

OCD1;135861316]Two things.

How did you measure your powder charge. Was each individual charge weighed?

This was the first question that came to my mind.

The second thing that I was reminded of was that the rds. need to go through the chrony in pretty much the same place every shot, I set mine up with a downrange target viewable through the sky screens. I shoot from the same position (usually off my range bag or a rest) and aim to the same place on the target.

Your extreme spreads seem to be a bit spaced out.


WG840

 

[alwslate]

I have chronographed a great many cast bullet handloads with a variety
of powders using varying charge weights in 38spl. Quite a few factory
loads as well. The frustating reality with the 38spl is that with typical
charge weights there is lots of air space in the case. Most powders are
position sensitive and two shots may vary by more than 100fps when
the powder is back against the primer or forward near the base of the
bullet. I have seen factory loads differ by 150fps or even more when
the gun is pointed up or down to position the powder before firing.
Try this yourself. Wad cutters seat deeper and reduce the air space.
Some powders are worse than others and 231 is probably about
average in this tendency. Easy to ignite fast burners like Bullseye
do a little better for me. Win 452AA actually shows the opposite effect
in my loads with higher velocity when the powder is against the
bullet. I have seen this many times in my handloads. I told this to a
Hodgdon rep on the phone and he basically called me a liar. Anyway
to compare loads you need consistancy so tilt your barrel up before
each shot is fired. Also be at least 10-12 ft from your start screen.
And if your using a Chrony don't expect too much. I gave up on mine
for handgun loads and use another brand.

 

[OKFC05]

lets hear what ya'll think.

I use HP38 all the time, in large quantities in .38. The results are not typical of anything expect poor technique, either in loading or using the chronograph. Without more information, it is impossible to way which, as at least half a dozen possible problems come to mind: inconsistent powder charges, too close to chrono, sun in chrono, varying powder position with gun tilt, varying distance, sample size too small for statistical significance.

 

[Skip Sackett]

To be really consistent, the brass should all be the same.

Exactly. Mixing brass and expecting results to be consistent is kind of silly. I have chronographed a bunch that way too but I kind of expect wide swings when I do.

I for one would like to see how you do with brass that is more segregated.

 

[m657]

For my own experiments at attempted science of ballistic performance, the hypothesis resulting from that effort, pointed to the notion that 'experimental variability' was beyond my capacity to control.

This was further demonstrated by the reality my own hands-on performance of accuracy varies more widely than the components of the handload.

In reality, my need for accuracy is that of "minute of grapefruit" at under 25 yards.

I have achieved that with all my various loads, and I no longer chase those entertaining numbers about on the chronograph. It has become enough that all my loads ignite to launch the slug downrange without causing a KaBoom.

YMMV.

 

[Rule3]

For my own experiments at attempted science of ballistic performance, the hypothesis resulting from that effort, pointed to the notion that 'experimental variability' was beyond my capacity to control.

This was further demonstrated by the reality my own hands-on performance of accuracy varies more widely than the components of the handload.

In reality, my need for accuracy is that of "minute of grapefruit" at under 25 yards.

I have achieved that with all my various loads, and I no longer chase those entertaining numbers about on the chronograph. It has become enough that all my loads ignite to launch the slug downrange without causing a KaBoom.

YMMV.

You owe me a keyboard as I just spewed coffee all over mine!

My personal expectations are very similar only I use "minute of paper plate (large)

 

[ArchAngelCD]

Last time I checked I was getting an average of ~700 fps from a charge of 4.0gr W231 under a 158gr LSWC from a 4" barrel. That's my favorite load like I said in the other thread made by the OP.

Those look like typical results, thanks for taking the time to post the data "shortround451".

 

[acl864]

Some old data of mine for reference:
38 Sp./148 Gr. TVB DEWC/CCI 500/3.7 Gr w231/S&W M19 2 1/2" Barrel/Temp. 75 F/ 5 MPH SSW/ 10 Shot String
Low-716/Hi-746/Avg- 731/Spread- 29.99/SD- 11.22

38 Sp./148 Gr. TVB DEWC/CCI 500/3.7 Gr w231/S&W M642 1 7/8" Barrel/Temp. 70 F/ 5 MPH S/ 8 Shot String
Low-683/Hi-730/Avg- 705/Spread- 46.6/SD- 15.8

 

[cjw3]

After posting last night asking what W231 loads everyone was using with 38 Spl I was able to chronograph my loads today. I got some interesting results. The loads were fired from a 3" Model 65. I fired two five round strings with each powder charge and bullet combination. Cases were mixed, both nickel plated and brass, and have been fired numerous times. :

4.2 grains W231 with Hardcast 158gr LSWC
1st string- 681 avg.FPS, ES- 125, SD- 45, High/Low- 734/608
2nd string-701 avg. FPS, ES-93, SD-38, High/Low- 749/655

3.9 grains W231 with Hardcast 158gr LSWC
1st string- 707 avg. FPS, ES- 24, SD-10, High/Low- 718/694
2nd string- 712 avg. fps, ES-29, SD-11, High/Low-724/694

4.2 grains W231 with Hardcast 148gr BBWC
1st string- 785 avg. FPS, ES-49, SD-21, High/Low- 807/757
2ns string- 795 avg. FPS, ES-27, SD-10, High/Low- 807/780

3.9 grains W231 with Hardcast 148gr BBWC
1st string- 772 avg. FPS, ES-24, SD-9., High/Low- 780/755
2nd string- 784 avg. FPS, ES-30, SD-16, High/Low- 803/773- This was a 3 round string as I ran out of ammo.

I am a little confused with the numbers from the 4.2gr/ 158 SWC load. The ES and SD were a little extreme and the average velocity was lower than the lighter load. My experience has shown that a high or low SD don't always show how accurate the load will be but I'm not sure what is going on with this load. The other numbers for the rest were about what I expected. I didn't shoot any groups but all loads shot well and seemed to shoot to point of aim.
I'm planning to load up some more and repeat this to see if the numbers hold up, and check accuracy, but in the meantime lets hear what ya'll think.

I don't really see anything especially wrong or odd with what you have. The results are pretty similar to some that I have gotten, but you might get a better idea of how things are if you will use 10-shot strings.

SD is just one part of what makes up accuracy and can easily be negated by a number of other things. Consistency in all things is best, but I also don't care to obsess too much about it for my own use.