Here is Edgar Brothers' latest listings (from its website) for the Alliant powders that it distributes:
Alliant
As far as I can see, the entire US range is now covered
except 1) Re17; 2) The 'Power-Pro' quartet of 'spherical' powders, ie Power-Pro 1200-R, 2000-MR, 4000-MR, and Varmint.
Re17
IS the same thing as Nitrochemie's Reload Swiss RS60 (factory production code: EI-Niesen 145. EI means it has the 'EI' advanced infused deterrents technology and all Niesen code products have infused nitroglycerin, ie are 'high-energy' propellants.) It is also the same product that was sold in the UK for a couple of years under the 'Elcho-17' name, this imported in bulk from the Swiss factory and bottled in 1kg lots in-country.
The Power-Pro propellants are all ball type powders and are manufactured by General Dynamics St. Marks Powder Co. in Florida which also makes all Winchester brand propellants and all of those Hodgdon grades described as 'spherical'. I assume they aren't Reach compliant (like all but the newest St Marks powders). In any event, they've never been imported into Europe AFAIK.
I have often seen it said that the factory gate bulk version of EI-N145 is loaded into Swiss GP11 7.5X55mm ball cartridges, but cannot confirm if that's so. In any event, it is a very good match.
Its single-based non-EI stablemate - WLP 225, sold as Reload Swiss RS62 - was originally developed by Nitrochemie for standard 270 Win loadings in factory ammunition.
Alliant Reloder 16 is not linked to these powders in any way originating from another company - Eurenco Bofors in Sweden - and using different technologies. Like Re17/RS60 (and all Bofors manufactured Alliant or Norma powders) it is double-based and is one of three new grades with Bofors' 'TZ' temperature control technology - which allegedly really works making Re16 as temperature unaffected as its main rival in the USA, Hodgdon H4350. H4350, Re16, RS62, and Re17/RS60 fall withing the same overall burning rate bracket and share applications. They aren't interchangeable though and the proper loads data-set must be used and loads re-worked up from scratch if a change is made.
6.5X55mm MAPs are a tricky subject open to various interpretations. US SAAMI for 6.5X55 is 46,000 CUP (Copper Units of Pressure - the old copper crusher pressure measuring system) which equates to around 50,000 psi using modern systems. CIP for the 6.5X55mm
SE is 3,800 bar / 55,114 psi. 'SE' is the key factor with it denoting the cartridge's use in modern rifles, and is also that applied by Vihtavuori in its data listed as '6.5X55mm SKAN', lower loads provided for in a separate '6.5X55mm Swedish Mauser' table are milder and to be used in old military rifles in good condition.
Some US loading data-sets specifically mention 'SE' in the table heading so
should conform to the higher CIP MAP value. Others say something to the effect of 'for modern rifles in good condition'. Others say damn all. What pressures any of them
actually work to in either handloading data or factory loaded ammunition is pretty opaque and with US companies' concern over injured user litigation they probably play safe. Certainly, Norma ammunition tends to be loaded significantly more heavily than most US equivalents.
Even with full CIP SE PMax, a full (60-62,000 psi)-pressure 6.5 Creedmoor load will match the 6.5X55's performance. Many factory Creedmoor loads which are usually kept down to 58,000 psi will produce a little less velocity than the hottest 6.5X55 equivalents. In real life there is nothing significant between 6.5X47 Lapua, 260 Rem, 6.5 Creedmoor and 6.5X55SE performance and potentials. There are many reasons for preferring one over another, but performance isn't one of them. Because of its significant case taper and relatively shallow shoulder angle, the 6.5X55 can be 'improved' significantly. Traditionally this was the 'AI' version, but there are a number of more recent variations such as the 6.5X55 GWI which produce better performance than the other three cartridges can offer. The 260AI improved version is less fashionable these days but won't be far behind the GWI etc and this pair would then outperform the 6.5X47mm Lapua and 6.5 Creedmoor. This is academic to most users though and certainly to British stalkers.