Another trip down memory lane. As i remember the first time I saw 3100 it was MR3100. It came in two pound white bottles and was imported from Israel.
Israeli sourced Accurate Arms powders predated the Explosia / Lovex (Czech-origin) ones, taking us back to sometime in the 1980s.
MR3100 had a reputation for being ballistically near identical to IMR-4831 and use of 4831 data being safe. Moreover it came without any lot numbers as there was only one (huge) lot imported into the the US by the old Accurate Arms Co. This version was tested in
Handloader magazine #92 (year?) by Bob Hagel and its very close similarity to IMR-4831 confirmed.
Gary Sitton gave this background when he retested 3100, now AAC-3100, 10 years later and published in
Handloader (issue? Year?) This is in Wolfe Publishing's
Propellant Profiles 6th edition (the collected powder tests of
Handloader 1966-2008). This 3100 version, which I'm 99% certain will be the Explosia / Lovex version was very different to IMR-4831 producing MVs nearly 10% lower in 243 Win, 280 Rem and 338 Win Mag. It was obviously slower burning (and according to QuickLOAD has less energy too).
We still have Czech Lovex SO-71 (as per AAC-3100) in the UK. My experience is close to that of Gary Sitton's. It can be a useful slow burner for large over bore capacity cartridges such a 6.5-284, but in many applications that see use by the 4350s and 4831s, you can't get enough SO-71 into the case to obtain full pressures and MVs. That's not to say results otherwise are poor as it seems to be a very tolerant propellant that works happily with low to medium pressures. For instance, I use this powder to produce very consistent and accurate loads in 7X57mm that match the original 1890s military loading - the Hornady 175gn RNSP vice the original 173 RNFMJ at 2,300 fps from a 29.3-inch barrel Chilean M1895 long infantry rifle.
When Western Powders bought the old Accurate Arms, the new management ditched Explosia products and replaced them with similarly performing ones from General Dynamics, St. Marks Powder Co. FLA or Eurenco P B Clermont in Belgium (ball powders) and General Dynamics Valleyfield, Quebec Province, Canada (extruded grades and the makers of most IMR modern powders for Hodgdon). Western either only offered a 'new' 3100 briefly, or more likely not at all, as there was no close equivalent available from its new sources. Last time I looked Shooters World didn't import this grade, but who knows it still do it. Nevertheless, I suspect not as SO-71 doesn't really have that many uses where it really shines, at least not in today's market where high MVs are regarded as essential.
