9mm help

[ryanv]

I just bought some 9mm 120 gr fmj bullets and need help with load data I am using Winchester 231 powder and my book doesn’t list it for 120 gr fmj. It says 4.3 min 4.8 max for 115 gr and 4.2 min 4.5 max for 124 gr any help would be much appreciated
Thanks Ryan

 

[mudgunner49]

I just bought some 9mm 120 gr fmj bullets and need help with load data I am using Winchester 231 powder and my book doesn’t list it for 120 gr fmj. It says 4.3 min 4.8 max for 115 gr and 4.2 min 4.5 max for 124 gr any help would be much appreciated
Thanks Ryan

Extrapolation is your friend - or you could just use the 124 gr data...


blake

 

[relliott]

Most pistol powders are linear in their burn rates relative to charge weights, so start with a light load (like 4.3 gr.) and run it over a chronograph to get a base line. Once you have this data you can do a linear projection to get what charge weight you will need to make whatever power factor you want. Power factor = (speed in fps) X (bullet weight in grains)

So divide your actual power factor into the power factor you want, and multiply this number by charge weight in grains. That will give you the charge weight you need. For example:
Target power factor (130) / actual power factor (120) X charge weight (4.2) = 4.5 grains.
These are not real numbers. They are meant only for demonstration purposes.

 

[colinjw]

It says 4.3 min 4.8 max for 115 gr

I see this on the Hodgdon powder web site but this data is for a 115 grain lead bullet rather than an FMJ.

You can come up with a powder charge for say a 120 grain by going in the middle of a 115 & 124 grain except I would caution you not to mix up lead & copper jackets in this. Especially with the 9mm case which is small & easy to create excess pressures in anyway.

 

[SandRoad]

What are you loading for? If you don't need full power loads, just use the 124gr data.