Nosler Projectiles in 243 Winchester
The day dawned with gusting winds and rain. Undeterred by the vagrancies of the local weather, I headed off to the range to continue my testing of Nosler projectiles in 243 Winchester. More specifically, 90 grain Accubonds and 85 grain Partitions in the Sauer 101 Classic XT.
By the time I reached the range, it had at least stopped raining. The wind gusts were, however, strong and variable; not a good day for group shooting. Having previously determined that 45.7 grains of AR2213SC (H4831SC in the USA) was the preferred charge with the 90 grain Nosler Accubond, I today tested variation in bullet seating depth.
As you can see from the graphs, the sweet spot seems to be at either 10 or 80 thou clear of the lands. I reckon I will adopt the 80 thou clearance for my standard loading of the Nosler 90 grain Accubond in the Sauer 101 Classic XT. Between groups, I tweaked the sighting of the Zeiss 3-9×40 scope to give a POI around 40mm high (the old inch & a half rule of thumb in metric form) at 100 yards.
Having cleaned the Sauer thoroughly, and fired a couple of foulers, I started with the 85 grain Nosler Partitions. The Partition is my favourite projectile in any calibre from .22 to .458, with excellent terminal ballistic performance. Generally, it does not quite match the Accubond or Ballistic Tip for accuracy. Typically, in most calibres I have tested, the Accubonds average a smidge under MOA and the Partitions a smidge over MOA. That difference is insignificant in a hunting situation.
There were two sweet spots that showed up from the testing of the 85 grain Nosler Partition. One was at 35.5 grains and the other at 38.0 grains, which is the ADI recommended maximum load of AR2208 (Varget in the USA). The fired shells showed no undue signs of pressure, so I will next try seating variations of the 85 grain Nosler Partition based on the 38.0 grain loading of AR2208.
Pleasingly, both the 90 grain Accubond and the 85 grain Partition had the same POI at 100 metres. That means I do not yet have to make a decision on which one to sight for in hunting trials.