Working up a load

[3djedi]

What is the process for working up a load and selecting the grains of powder and OAL for PF and accuracy?

Or if you have a website or a book that describes the process that would be awesome.

Thanks!

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[Dirty Rod]

OAL is really gun dependent. You should pick an OAL that feeds reliably so I always recommend using the OAL for whatever factory load works well in your gun as a start. Once you have the process and loads down you can tweak the OAL but always start with an OAL for the type of bullet you are loading.

Working up a load is generally done by starting at the lower end of the powder range by loading 5 rounds at the low end of the scale, load 5 more increasing the charge by .2 gr, etc, etc until you find loads that are the most accurate while staying below the max charge listed and watching for pressure signs.

Once you get your most accurate loads you can then chrono for velocity and PF. Hopefully you have multiple reloading manuals to cross reference. If not, I'd recommend picking up the Lyman reloading manual and reading the ABCs of Reloading before loading any rounds.

Edited March 18, 2014 by Dirty Rod

[Dkrad1935]

Love the title of this thread. I'm just sayin

[3djedi]

I do have Lymans but not the abc book. I haven't found anything about the process of picking a load for PF and accuracy. What I have read said pick something in the middle of loading data and how to actually load on the press. I'm looking for info on competition specific process.

Do you test each powder charge through a chronograph. Pick the range that fits the PF and then test each of those for accuracy? And load data may say 1.15oal but your gun likes 1.10 How do you know how to adjust the powder in this situation?

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[3djedi]

Love the title of this thread. I'm just sayin

I'm workin' up a load right now.

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[Dirty Rod]

Do you test each powder charge through a chronograph. Pick the range that fits the PF and then test each of those for accuracy?

I find an accurate load and then chrono. IMO, if the load isn't accurate it doesn't matter how fast it's going and you also have a fair amount of variability in many powders. I shoot mostly 230gr .45 using 231 so hitting 165k PF means I only need to get the bullet moving 718fps. If you look at your Lyman book it's got a starting load of 5.2 estimated at 758fps so I'm already at the PF. Just for kicks I started at 4.8gr working up and found my most accurate load around 5.3 so that's what I use. The actual velocity I get doesn't exactly match the book but it's well over the PF I was trying to hit. My wife's was pretty much the same once I stropped trying to make a 115gr bullet hit PF out of a 3" barrel. I switched to a 147gr bullet and only needed to hit 850fps for a 125k PF.

I sometimes do a slightly different routine for rifle. I start with a ladder test to get at least in the ballpark and then start working up for accuracy. Saves a bit of powder that way.

And load data may say 1.15oal but your gun likes 1.10 How do you know how to adjust the powder in this situation?

If your OAL is shorter than what's listed just back down the starting charge weight. Unless you are loading close to max a .05 drop is not going to make a noticeable difference but drop your starting load to be safe.

Edited March 18, 2014 by Dirty Rod

[ttolliver]

Since we're all focused on competition, all of the recommendations for powder and bullet weights you get here are going to be setting you up for competition. Once you pick a powder and bullet weight to tinker with, just go ahead and follow the book recipes for normal load development with that combination and focus on coming up with a good accurate load for your gun. It's possible it might not make PF in your particular gun, but there's a good chance it will because you started with recommendations that are generally known to make PF.

For most powders the powder spread from the reloading manual will be fairly wide, say something like 3.4 to 4.2 grains. Load up around 20 of each charge weight in that range by .2 increments (.3 increments for really wide ranges, .1 for really small ranges like maybe Titegroup). That gives you enough to shoot 10 through the chrono and use the other 10 for accuracy testing (two 5 round groups is my favorite).

As a side note, even if you read time and again that everyone's favorite load is 4.1 grains, still do the exercise of 3.4 to 4.2. Your particular gun's sweet spot could be at 3.9. But if you take a shortcut and decide to load some at 4.0, 4.1, and 4.2 to explore immediately around the recommended 4.1 it'll take you longer to figure that out. So just be patient and run the whole range.

Generalizing, with any spread of powder charges you'll see the group size progress from larger to small and then start to get bigger again. Just made up numbers, say 3.4 was 2.5", 3.6 was 2", 3.8 was 1.75", 4.0 was 1.85", and 4.2 was 2". In that case it looks like the sweet spot is somewhere around the 3.8 to 4.0 grain neighborhood. At this point you already have chrono data on 3.8 and 4.0 to see where those loads fall with respect to PF. So if they're nowhere close you could make the call now that this isn't a load to pursue. Otherwise head back to the range next time with another batch of 100, this time maybe loaded as 30, 40, 30 of 3.8, 3.9, and 4.0 respectively. This trip is where you really focus in on which of those loads is the most accurate.

Good luck!

[practical_man]

Since we're all focused on competition, all of the recommendations for powder and bullet weights you get here are going to be setting you up for competition. Once you pick a powder and bullet weight to tinker with, just go ahead and follow the book recipes for normal load development with that combination and focus on coming up with a good accurate load for your gun. It's possible it might not make PF in your particular gun, but there's a good chance it will because you started with recommendations that are generally known to make PF.

For most powders the powder spread from the reloading manual will be fairly wide, say something like 3.4 to 4.2 grains. Load up around 20 of each charge weight in that range by .2 increments (.3 increments for really wide ranges, .1 for really small ranges like maybe Titegroup). That gives you enough to shoot 10 through the chrono and use the other 10 for accuracy testing (two 5 round groups is my favorite).

As a side note, even if you read time and again that everyone's favorite load is 4.1 grains, still do the exercise of 3.4 to 4.2. Your particular gun's sweet spot could be at 3.9. But if you take a shortcut and decide to load some at 4.0, 4.1, and 4.2 to explore immediately around the recommended 4.1 it'll take you longer to figure that out. So just be patient and run the whole range.

Generalizing, with any spread of powder charges you'll see the group size progress from larger to small and then start to get bigger again. Just made up numbers, say 3.4 was 2.5", 3.6 was 2", 3.8 was 1.75", 4.0 was 1.85", and 4.2 was 2". In that case it looks like the sweet spot is somewhere around the 3.8 to 4.0 grain neighborhood. At this point you already have chrono data on 3.8 and 4.0 to see where those loads fall with respect to PF. So if they're nowhere close you could make the call now that this isn't a load to pursue. Otherwise head back to the range next time with another batch of 100, this time maybe loaded as 30, 40, 30 of 3.8, 3.9, and 4.0 respectively. This trip is where you really focus in on which of those loads is the most accurate.

Good luck!

^^^^this is pretty good advice for the serious competitor. I use a variation on this technique when working up a load for a new gun, pistol or rifle. For shotgun I just follow the recipe from the powder manufacturer.

Of note, I have found that most powders are more accurate toward the high end of a given load range. Typically I get best accuracy somewhere around 80% of the total load range. EG, if the start is 5.6 and the max is 7.6, then total range is 2.0 grains. 80% is 1.6 grains. I expect best accuracy to be around 5.6+1.6 = 7.2, give or take a little. This could be an anomaly attributable to the relatively small number of powders I have used. Seems to hold generally true for me with 9mm, 45 ACP, 38 special, 44 Special, 223, 308, 9.3x62, and 6.5x55. It does not hold for 44 mag and 357 mag loaded with rifle powders. YMMV

I find OAL with dummy rounds. Once I have a starting OAL then I test for accuracy, then For power factor. Tweak OAL if required to get desired accuracy and power. Best accuracy is usually above PF minimums for me.

Hope this helps. Working up a load is interesting. More interesting now that I have been using quick load software as a starting point. Someday we will have reliable component supplies and can slow down this experimentation.