General Rule of Thumb

[topclass2017]

As a basic rule of thumb...

If I have a bullet for which there is no load data (for example using an older manual that doesn't show newer bullets), as a starting point would I use data for the next lighter bullet or next heavier?

I know, invest in newer manuals. But I am looking for down and dirty, general conventional wisdom.

Thanks!

 

[Sniper338]

What are you shooting and what bullet and weight... give us some info.

For me it just depends what its closer to...

 

[topclass2017]

6.5 Creedmoor. Manual has data for 140-143 grain but not 147. So as a starting point, would I use 160 grain data or 140-143 for loading 147's?

 

[dolek]

From Hodgdon,maybe you have some of these powders ?

 

[Sniper338]

6.5 Creedmoor. Manual has data for 140-143 grain but not 147. So as a starting point, would I use 160 grain data or 140-143 for loading 147's?

147 is close enough to 143. Just start half a grain lower

 

[Sniper338]

The basic rule of thumb is a switch no larger than your thumb diameter to beat your wife.

FYI... the real meaning the saying was derived from.

 

[jepp2]

I know, invest in newer manuals.

It is rare that you can't find current load data on-line for most of the manufacturers. If the manufacturer doesn't have load data, search by cartridge.
https://load-data.nosler.com/
https://sierrabulletsblog.com/2017/01/09/sierra-bullets-6-5-creedmoor-load-data/
https://www.speer-ammo.com/downloads/speer/reloading-pdfs/Rifle/65mm_264_dia/65_Creedmoor_140.pdf
https://press.hornady.com/assets/site/hornady/files/load-data/6-5-creedmoor-147gr-data.pdf
https://www.starlinebrass.com/artic...r-guide-reloading-65-creedmoor-ballistics.pdf

 

[Bart B.]

Look at the round's data. Do heavier bullets list more powder for a given weight? Or less?

Adjust yours the same way.

 

[NorCalMikie]

147 is close enough to 143. Just start half a grain lower

That pretty much covers it. Adjust from there.

All my rigs are chambered in Wildcat rounds so I adjust from the start.

 

[dellet]

In addition to weight, you need to consider length. The trend recently has been to make everything longer, so an older manual could have other issues when changing bullets.

5 grains of additional weight at minimum charge may not have as much effect as .125” in length if seated to the same listed length.

JBM is a good source for bullet lengths online for comparison.
https://www.jbmballistics.com/ballistics/lengths/lengths.shtml

 

[Papa Charlie]

You can also send an email to the bullet manufacturer. Most if not all have a technical help group that can provide you with guidelines for any of their bullets. Keep in mind that their suggestions are most like going to be conservative, but it will give you a good starting point for load development.

 

[topclass2017]

thanks everyone. this has been helpful

 

[dsculley]

Actually, the original "Rule of thumb" was from marine navigation. Before the days of electronic navigation, the captain would place his thumb on the chart and try to keep his vessel one thumb width away from navigational hazards.

 

[Fotheringill]

As an aside on hodgdon-

Send them an e-mail telling them what round, powder and rifle you are using and they will give you the start and max loads. I did this for CFE 223 powder and Berger 73's. They responded within one day.