Excessive variation for N320 in .38 Sp.

[Cherryriver]

Always searching for the best way to drive Berry's 158 round-noses out of .38s and .357s, the one powder that seems like the answer for ,.38 Special is Vihta Vuori N320. 4.5gr gives the Berry's around 820-840 fps on a warm day, which is comfortably clear of the minor floor. The book max is 4.8 (for a similar Rainier), so it's not overboard and shoots really nicely.

But the main reason I backed away from all of the VVs a couple of years ago was the very high variation in velocity. I mean, so bad that even IDPA SOs comment on how it sounded like I'd just fired a semi-squib.

My chrono agrees. I did up a couple of hundred for my Detective Special for yesterday's local IDPA match (yes, it's very challenging that way) and then chronoed them afterwards.

One six-shot string had a 110fps spread, almost all of it due to one round of about 730fps, as I recall, and almost all the rest departing at just about 830. The sound and recoil difference was apparent, too.

Since I'm not having any such trouble with any other powder on the exact same Dillon setup, and this is something I've been noticing all along, I wonder if anyone experiences such wide variation with the VVs.

This isn't just one chamber of one gun- it happens all across the board with any of a half-dozen Colts and Smiths.

The primers used were Federal and Winchester both, with equal results.

I dumped N340 for .357 some time ago for the same reason.

Bill