The smaller case capacity will INCREASE pressure, gaining velocity with lower powder charges. You will see max pressure earlier, so be wary of this. I got caught out with Nosler brass due to less capacity than Rem or Win brass. Velocity was identical at 2grs' s less than either of the other brands.
Without a chrony, doping off shooting rocks is not going to be as accurate, the BC is not constant in all velocity ranges, and you may be off quite a ways from the actual dope.
MM, I agree ,,,but,, It usually takes 3 gr less in RWS brass due to the reduced volume and case fill, pressure shows up earlier. But at some point the larger charge usually over rides the spike from less case volume and the case with more capacity will produce more velocity. How much remains to be seen. An extreme example would be the RUM and 30-378. What I have seen with these Win cases and this exact bullet is RWS 74 gr WW 77 or 78 gr for a max with the WW having more velocity. All rifles are different, reamer throat length and seating depth will play a role here too. So we start low and work up to see what we get.
I do like to use a Chronograph, but in the end the drop are what we care about. I prefer to check drops on a vertical surface like paper or steel, but a vertical rock wall will work too. The advertised G7 BC of the bullet here (215 Berger) has been very accurate through the entire velocity range of the 300 win for us. With several rifles set up and checked, it has been a very good combination. Silly accurate to 12 or 1300 yards and still inside 1 moa at a mile in my rifle. So, as long as we are using a vertical surface to shoot groups, and can measure group center to point of aim with a tape or accurate measure of some sort. I prefer to go with real world data and use my chronographs to get me a close starting point. In the end if the rifle and ballistic app match that is what we really need.
I have never used the ladder/node shooting
before. Can you folks explain it a little so I can under stand how it works. I think I see what you do but it would help to read it from you guys. Thanks Ted
Ted, all it is, is a way to find the sweet spot where velocity stabilizes for a few grains of charge weight. You can see the loads grouped together around 76 gr.
I am just testing a rifle with 215's this am. I had a load worked up in Lapua / Norma brass but the brass seemed to be way soft to me. I have seen this before with Norma brass. Norma is typically soft, but some runs are way softer. At least that's my opinion. Anyway, I loaded 3 rounds of H-1000 in WW brass and shot them, 76, 77, 78 gr. They went into a .3 group. Two in the same hole one a little left. All 3 with different charges were dead nutz for elevation. I think it is safe to say I am in a "Node" for the rifle and load.
Jon, the 78 gr load seems a tad hot for me to in this rifle. No hard bolt lift but I think there was a slight loss of primer tension when I seated new primers. I am going out now to load some at 77 gr.
I will bet $ in a 28" tube , 77 gr with a 215 Hybrid, in WW brass will get me close to 2950 fps. We will see.