I know this powder was base off the A2520 powder, but I think that has changed somewhat in recent times, the A2520 I purchased a few yrs ago was made in CANADA, any further info on the SWMR in today's world is what I need to know, thanks.
SW Match Rifle is Lovex D0-73.6 with a new name and packaging imported into the US by Shooters World. For us in Europe it goes by the Lovex designation. Lovex powders are made by Explosia a.s in the Semtex region of the Czech Republic.
Until around 2003 it was sold in the US as AAC-2520 by the Accurate Arms Co. which produced its own (and very good too) reloading manual. Accurate Arms also imported, packaged and tested a range of Explosia tubular single-based grades such as AAC-2015, 4064, 4350 etc and a range of ball type pistol/revolver powders. In 2003, Western Powders of Montana bought Accurate Arms Co and added AAC's powders to its own grades, mostly Belgium manufactured Ramshot ball types. Although it retained the 'Accurate' brand name, shortened to that single word, it promptly terminated the former AAC's agreements with Explosia. Tubular grades were now made by General Dynamics' Valleyfield facility in Canada, ball powders mostly by General Dynamics' St. Marks factory in Florida. So, Accurate-2520 was a different powder even if it had similar characteristics and loading data to its AAC predecessor. There were hints that Accurate-2520 was a rebranded Ramshot powder made by Eurenco P B Clermont in Belgium that is sold in Europe as Ramshot 'Wild Boar', but it is definitely a St. Marks produced propellant these days. Ca. three years ago, Hodgdon Powder Co. bought Western and all 'Accurate' and 'Ramshot' brand powders are now part of the Hodgdon range even though they keep their existing brand names (and for the moment at least, their producers).
All Hodgdon 'Spherical' grade powders are also made by Gen Dynamics St. Marks. AAC / AA / Accurate-2520 was never made in Canada, either the Czech Republic or Florida depending on date, and as noted maybe Belgium for a time.
Returning to (Czech) SWMR, it'll be as temperature affected, or tolerant as the case may be, as other Explosia / Lovex ball types - that is not dreadful, but unlikely to be as good as with the most recent St. Marks developed types such as the Winchester StaBall products. It'll probably be in line with older Winchester / Hodgdon ball grades such as W748 H335, H. BLC-(2), W760/H414 and similar. The only way you'll find out for certain is through experience. Being in the UK, our weather is usually miserable or really, really miserable with 80F an exceptionally hot day, so we really don't worry much about this aspect of powders.