Spreadsheet for reloading

[twocan]

I've built a couple of spreadsheets that I think are handy so I thought that I would share them with the reloading community here.

I use one for documenting my load when I use a chronograph. It calculates the following for a 1 to 10 shot group for 7 different loads:

Number of shots
Lowest velocity
Highest velocity
Average Velocity
ES
Energy in ft. lbs
SD (note- Standard Deviation is a statistical value. 10 data points is the least number recommended by most chronograph mfgs and a very small sample. Statisticians will tell you that SD is only as good as the number of samples and they generally wrinkle their nose at a sample as small as 10. If you have less than 10 data points the spreadsheet will still calculate a result but it's probably not of much value)

Just fill in the blanks that you can before you go to the range and add the velocity and atmospheric data once you get there and start shooting. I take a printed copy with me but it will load on to a PDA (I loaded it on my Dell Axim 50). Once you get home you can type in the recorded values and do file Save As and save a copy specific to a particular test.

I also use the sheet when I don't use a chronograph. It's handy for keeping track of what loads that I've tried. I also have columns to record atmospheric data as well as data about the load that I am testing (caliber, BC, powder, bullet, etc.). The spreadsheet is protected to prevent accidental over writing of a formula. If someone wants the password I will gladly give it out. For that matter, if Len wants to include it when he edits the post that's fine with me. Who knows, maybe someone will get froggy and change the calcs to handle a larger sample size

I use the other spreadsheet to give me an overview of what charges I will use for a specific cartridge. When I go to the loading bench all I take with me is one sheet of paper rather than the manual. Once the loads are built I put the printout into the cartridge box with notes on which row contains which load. This doesn't sound like it would be that handy but I list every powder that I have on hand and I have a tab for rifle and a tab for pistol. I know this is going to make some long time reloaders wince a little but we have a lot of new to reloading people out there (that's a good thing). By listing all of the rifle powders on one tab and all of the pistol powders on another the likelihood of accidentally loading a rifle powder in a pistol case or vice-versa should be diminished since the "recipe" is for a specific powder is right there. Another benefit is that I only have load info for the powders that I have on hand. I don't have to worry about weeding through all of the other data. I thought about breaking it into caliber specific tabs but decided it would be more useful to more people if I did it this way. To tweak it to your liking just remove the powders that you don't have and add the ones that you do.

If Len posts the sheets that I sent him then they will already have data points entered in a couple of columns. Just delete the blue and red colored info. BTW- I used red to indicate max or over max charges in.

Feedback is appreciated but not necessary.

Thank you, Mike.

 

[Mike6158]

Man a lot has changed in my reloading steps since this post, It's gotten easier. Easier doesn't = cheaper. More shooting, more research, more understanding. I recently did an SD test. You know that old tootsie roll owl commercial where he tries to find out how many it takes to get to the center of a tootsie roll. I did a test to see how many shots it takes to get a useful SD. One day, when I'm shooting at 1,000 I'm going to shoot 30 to 50 for groups and record the velocity. And if/when I post the data someone will probably say that's not enough shots to get a useful SD value. I've used the sheet to test primers as well as seating depth. It can calculate the temperature at which a subsonic round is subsonic.

Here's a screenshot a the short version of an SD test I included in the overall test. Column 3, 5 shot group at 35 grains. Column 10, 5 shot group at 35 grains labeled sighters that I loaded with the loads in column 3. Column 9, combined both 35 grain groups.

This is my preliminary takeaway from the results

5 shot groups will identify a group that I can cull based on SD. Ie they'll never get better than what's in the 5 shot group, if it's not mid to low single digits I can look elsewhere. The second 5 shot group of 10 (column 10) was worse than the first one (column 3) and the combined was worse than either one. So shooting 5 shot groups isn't worthless but it doesn't tell the whole story either. If there's time, shooting 10 is better than shooting 5.

I have versions of this sheet for a lot of calibers. I usually have the bushing and mandrel size in the notes section. It's probably in one of the other tabs. There are multiple tabs of the same caliber. The sheet above has 7 different tabs (subs and subsonic). Note that these rounds were NOT subsonic in a shooter friendly environment (see bottom row).

Here's a different version of the same sheet. It's a friend of mine's 6.5 PRC. This sheet has a group size calc in it. To save a row I made it so you have to manually add the measured group size to each cell. I could make it so you have a row for measured size, a cell for distance shot, and a cell for bullet od and let it calculate group size in inches and moa.

We'll reshoot column 4 before the end of they year. At least 10 rounds just to confirm the SD wasn't a fluke. Column 8's group is legit but I doubt if it would repeat. It would be kind of funny if it did considering the ES/SD values. Merry Christmas everyone.