A while ago there was a question about using Vihtavuori powder for .380. Since a VV distributor lives just over the hill and my wife shoots .380, I worked up some loads using the 2002 VV Reloading Guide data. The loadings described below are intended for use at the range. Perhaps another reader will find this experience useful.
COAL is the spec’ed 0.98”
Bullets are Berry’s 100gn HBRN
The VV guide says for the 100gn FMJ with a 3 ½” test barrel
N310 Max 2.6gn 912 fps
N320 Max 3.4 gn 1007 fps
The firearms used with the loadings were the Sig P230 and P238. Shorter barrels than VV used to generate the data.
The Berry's are copper plated and the VV data is for FMJ. The loads described below were reduced to account for this.
Using CCI Small Pistol Primers started with VV N320 and 2.7gn. This loading was soft shooting and both pistols ejected and fed OK. The only negative was some unburned powder landing on the table under the pistol. Likely due to the barrel length vs the speed of the powder. The shooter liked the load and was accurate with it so did not explore higher power loadings.
Using CCI Small Pistol Primers, loaded VV N310.
2.1 gn worked OK in the P230 but the P238 did not reliably eject and feed. Observed some unburned power on the table under the pistol after shooting. This was a surprise as N310 is a fast powder.
2.3 gn resulted in reliable ejection and feeding with both pistols. Again observed some unburned powder on the table under the pistol after shooting.
These loadings were soft shooting and the shooter was accurate with these loadings. The N310 loadings were reported to be softer shooting than the N320 loading.
In order to compose a load that has the same power factor but more completely burns the powder, put together:
Winchester Small Pistol Magnum primers with 2.1 gn VV N310.
This combination resulted in reliable ejection and feeding with both pistols, and no unburned powder on the table.
If you try these loadings, all cautions apply. Please note that N310 is one of the fastest powders listed on the burn rate chart.
The work was done on a Hornady Lock-N-Load progressive press with Lee dies.
Hope this info is useful.