@Relja how did things go with the barrel? Did you end up making a decision on the powder? I am starting to get some components together for 300NM and I’ve used N568 for my 300PRC so I am chasing after some indicators I can just stick with it for ELR for both cartridges. (vs N565 or N570). Probably same 230 OTM for both at least initially but I’d like to get the 215 Berger and probably some Warner solids.
Nazarsh: I have tested N568 in a new 300 CA carbon 26" Barrel with 225 ELD-Ms, kissing the lands (about 0.007" off Jam) and got incredible accuracy on the top end.
I don't have any chronograph data yet (MagentoSpeed V3) and probably won't be able to test velocity data till December as I am focused on reloading/shooting both 308 and 300 WM to prepare my son for his first hunt where most opportunities presents themselves between 300-600 meters, we/he needs to practice a lot from different improvised shooting positions.
I think N568 is likely to work well for you but it might not get you the same top end velocities as N570 or Norma N-217. With the later, in a different rifle chambered in 300 Norma as well, I am getting 3065 fps with 230 gr. A-tips, using just below Norma's max published load, herein attached.
Note: the VihtaVuori loading tables may be conservative, based on published burn rate and in comparison with N217 Norma load data which has a max load of 87.0 gr. for the 230 Gr. Bergers VS 83.5 for N568 on the VV load data for 230 gr. A-tips (load data from Norma and VihtaVuori are attached).
Safety notes: Norma N-217's burn rate shows to be a bit faster then N568 but on my CA 300 Norma's barrel, I am seeing the pressure signs with N568 come in sooner than I would expect based on my experience with N217 which had no pressure signs across all temperature previously tested. This could be due to the 2 powder's characteristics where the Norma N217 powder may have lower primary pressures with higher secondary pressures compared to that of N568, or, it could be due to the 2 barrel's chamber's individual differences... Both variables, chamber differences and primary/Secondary pressures of N217 & N568 could contribute to N568 showing pressure signs sooner despite being a slower powder then N217.
I dare not say what the causal factors are, but I just wanted to warn you and other reloading their 300 Norma with N568 not to make the assumption that because the max load for N217 is 87.0 gr., no-one should not be thinking that you may be able to run near 87.0 gr. of N568 despite the fact that on paper it is slower powder.
Maybe somebody with Quick-load could compare Norma N217 max load of 87.0 grain chambered in 300 Norma with a 230 gr. berger VS 83.5 gr. and 87.0 gr. N568. The later charge would be way over pressure in my CA Carbon barrel but might be OK in my other barrel which has a longer throat and was built to handle higher pressures: 65,000 PSI and tested 50% above that for safety by the ODM; I never reached pressure signs in that barrel near max charge with N217 even in 109 °F heat.
I also tested N568 with 210 Gr. AccuBonds: one hole accuracy as well but it is hitting pressure a bit earlier than I would have expected in my particular chamber (Velocity testing is set for Dec.).
The advantage of N568 is claimed to be its temperature stability and non-hydroscopic characteristics. The later is very important, as humidity content in the powder can create significant Velocity changes, hence N568 is probably ideal for hunting and some precision applications and while N565 has very similar characteristics, you should be able to get better case fill with N568 over N565 due to its slower burn rate (Please refer to VV load data herein attached).
From the Vihtavuori loading manual: "N568’s slow burning characteristics and short-cut grains provides extremely consistent metering for long range competitive shooters, accuracy enthusiasts, and hunters alike. N568 excels with heavy-for-caliber projectiles and provides exceptional temperature stability and is insensitive to humidity changes".
In my experience, with N568 shooting 225 ELD-Ms and 210 LR Accubonds, using new 300 Norma chambering Lapua brass, the first sign of pressures were with the primers (Fed. Mag. Primers, #GM215M).
In summary, I think it will be worth your time to work up a load with N568, please be safe and work up! Best - Chris
