The Norma powders are made by Bofors, the same Swedish plant that produces Alliant Reloder powders (except 17 and 33, which are made in Switzerland). The Normas seem to share some of the same characteristics as Reloder 19, 22 and 25: fine accuracy, top velocities, and some loss of velocity in cold temperatures. But Reloder 15 was reformulated a while back to be more temp-resistant, due to demands from the military, and is pretty good, so there's no reason they can't produce more temp-resistant powders.
The only Norma powder I've formally tested in cold weather was 204 and it lost over 100 fps from 70 to zero in a 165-grain .30-06 loads. Results with the others during range sessions at various temps from the 30's to 80's indicate they aren't in the same league as the Hodgdon Extremes as far as temp-resistance.
While Norma's max loads indicate URP is in the same burn-rate range as 204, according to Norma's data higher velocities can be attained with URP. I got almost 2900 from the 21" barrel of my 6.5x55 with 45.0 URP and the 130 AccuBond.
Another outstanding loads in my rifle is 45.0 204 and the 120 Ballistic Tip, for just under 3000 from the short barrel and very good accuracy. I came up with the load by breaking down a Norma factory round with the 120 BT that shot very well, and compared the charge to their data. The handload duplicated the factory ammo in accuracy and velocity.
45.0 Norma 203-B worked very well with the 85-grain Sierra, but not quite as well as 45.0 Varget in either velocity or accuracy. In fact the Varget 85-grain load was the most accurate tested, proving once again that well-balanced light bullets will shoot well in fast twists. My rifle has a 1-8 Lilja.
