by dickw5000 » 05 Jul 2016, 12:17 pm
The best powder is the one that works best with your rifle and your projectiles. I have a Weatherby Vanguard in .223 that is around 15 years old. When it was new I got reasonable accuracy with factory loads.
I tried W748 with Winchester 55gr PSP and Nosler shots. I got a good load for the Winchesters. I tried BM1 and could not get a consistent grouping and the Nosler / BM1 combination was awful.
I then tried AR2207 and Hornady 55gr spire soft points. 20.2 grains gave me an exceptional grouping, consistently 10 - 12 mm groups at 100m. I think that is outstanding for a budget / mid-price rifle with no work done on it. I've now put close to 7 kg of AR2207 through that barrel and it is still grouping consistently tight. I must be close to 7,000 rounds through that barrel and no signs of accuracy issues.
20.2 gr of AR2207, especially when I buy the 4kg container and bulk projectiles (Hornady SP and Sierra 55gr Gameking / Roo Load) give me a very economical load. It used to be around 33 cents including primer when the Hornady's were $120 per 1000. I think the Sierra's were $130 per 1000, but have gone up.
I have some reduced velocity loads that I use on rabbits and hares and they are equally accurate (7.5gr of Green Dot behind 46gr HP) which gives a nice quiet, tight group out to 100m, but not much more. I am working on a 40gr Z-Max SR4759 load as an alternative to a 17HMR.
My advice is buy 500gr containers of candidate powders, make up loads of 6 rounds of each load from min to max in 0.2 grain increments and shoot 3 shot groups with a cool and warm barrel off a sand bag and record the results. You should find a sweet spot for accuracy, which is what matters right? Give me 2900 fps and 12mm @ 100m grouping over 3250 fps and 25-50mm @ 100m, which might be flatter at 250m, but may not hit a fox's head.
You may find a corelation between powder capacity and accuracy, that is, I find that 1.52cc of powder (regardless of weight / density) seems to be optimum in my rifle. So you may not need to load from mid recommended load to max, if other powders has the groups open up towards max load. Your rifle may be different, but I found a similar pattern with my Howa 1500 in 6.5x55.
Never go outside the load manual's min and max loads for the specified projectile weight and be safe.