More 124 chrono data with WW231

[Jmoser]

Reduced to 3.6 gr WW231 with Missouri coated 124 LSWC, 1025 fps in the SP-01;  accurate and reliable with 13 lb spring.  SD 10.8, 35 fps spread over 10 shots.  Mixed brass and Fed primers.

For comparison 3.8 gr was 1075

Wanted a bit slower but not worth the hassle to recalibrate sights and springs, gonna stick with this.

[Crawl]

Funny, I just tested 125gr LRN from Blue Bullets today with 3.6gr of Zip (adjacent to 231 on the burn rate chart). Avg 984fps, SD of 20, Spread of 71fps.

My loads aren't super consistent though, I'm using a Hornady Progressive, and Zip just doesn't flow that well. Still some of the most accurate stuff I've ever shot.

[Jmoser]

My SP-01 has extended bbl,  over 5".   Easily can explain 40 fps.  Also .0005" in bullet sizing will influence pressure, etc etc etc.  Think of it as 1000 fps +/- 20 fps not to mention 2 different powders.  Relative burn rate isn't enough to directly substitute data.  Never used zip.

[Crawl]

I was shooting them through an S2, so barrel length isn't a significant difference. I simply found it funny that you were testing a load so similar to what I was testing. Seems like Zip is pretty fast and produces more consistent loads when loaded hotter. I'm guessing this brun rate (Zip/231) is better suited to shorter COLs

[Jmoser]

I also load with WST which is faster, at 900 fps I get SD of 3.  Also got a lower SD at higher velocity with 231.
It's just finding the sweet spot in the pressure curve; 9mm case capacity  is so small that things change fast with .2 grains and .02 COL.

[Crawl]

What powder drop do you use? I've always heard that people love the Hornady one, and that's what I have. It seems to vary by +/-.2 grains, but I still get my best groups with these handload nonetheless.

[Jmoser]

All my 9mm is off a Dillon 550.  Most pistol powders meter quite well in most dispensers, it's the rifle stick powders that hang up [Varget.]

I throw 10 charges to get avg weight, below 3 gr use the XS bar.   We shoot a lot of powderpuff .32 and .38 with 1.3-2.5 gr;  bunch of us got brass bar stock, machined to dimensions and reamed fixed holes to set various charges.  Extreme I know but it works like a charm and 100% repeatable.  I have 5 or 6 bars like this.

[Radom]

Don't shoot mixed headstamps.  You'll see a dramatic improvement in performance, if only because the primer seating is more consistent (same case =same primer pocket).   

[Wobbly]

And use the template provided for reporting. That will remind you of things that help.

[Crawl]

And use the template provided for reporting. That will remind you of things that help.

I'm not 100% certain of what you're referring to.

[Crawl]

Don't shoot mixed headstamps.  You'll see a dramatic improvement in performance, if only because the primer seating is more consistent (same case =same primer pocket).

Even if my powder charges are two tenths of a grain different at times?

[painter]

And use the template provided for reporting. That will remind you of things that help.

I'm not 100% certain of what you're referring to.

https://czfirearms.us/index.php?topic=79410.0

It makes sure you provide all the relevant info.

[Crawl]

Fantastic! Thank you!

[Wobbly]

Even if my powder charges are two tenths of a grain different at times?

There's no need to report ANY of your data until your powder "drops" get far, far more accurate than that.  I highly suggest you sit down with your machine and drop 100 loads of powder. Weigh all the drops and plug that into Excel. You can then get a plot of your results and visually see where and when it happens.

BTW, you'll also need to verify your scale is repeatable and accurate, to do that exercise.

 

[Crawl]

I'm getting SDs around 7fps in 10-round groups. This is without sorting my brass. Is it reasonable to try to get the loads even MORE consistent?