Tim, Here's a recipe for 223 using either 52, 53, or 55 grain bullets.
26.5 grains of BLC-2 or H-335 with a CCI SRM primer. Velocity has been around 3300 fps and accuracy has been outstanding. I've tried that load combination is no fewer than 15 rifles now, using WW and Rem and FED brass. The only problem I've had is with military brass. This load is very marginally over capacity, so load it carefully.
To answer your questions about choosing a powder, there are a couple of things I consider. Bullet weight, barrel length, rifle preference for other loads.
Generally speaking, you need slower powders for use with heavier bullets. Faster powders for ligher bullets. Using a longer barrel you can burn a higher quantity of slow powder. Using the same powder in a shorter barrel will be a waste of time. I'll tell you a secret that becomes truer the longer I load.
If you find a load with a specific weight bullet the shoots well, you are better off using the same weight of a faster or slower powder for a heavier or lighter bullet.
I prefer using a ball powder when I can. It measures better, burns cooler and tends to be more consistant than Lincoln log extruded powder. Mostly with a new rifle, it's just experimentation.. Keep fooling around until you hind one that your rifle likes..
