Been a while since I've been here, but I'm looking for a new reloading project and I'm hoping some of you might help me with a bit of preliminary information.
Here's the background: I've got a mate who's thinking about getting and running a .45-70 as his woodland stalking rifle. His variation's gone in and he seems pretty sure to get it. I'm rather jealous of that and I'd love to get one too, since I've always liked the idea of using one of "ye olde" ex-blackpowder calibres and it fits with my personal approach on ballistics / meat damage etc. Only problem is that I probably don't do enough stalking at this point (with a 6-month old to look after) to justify another deer rifle to the FEO, so it'll have to wait a few years until I can hunt more often.
So, all that in mind, I thought it might be fun to see if I could copy the approach, if not the implementation: I'd like to load up a really heavy (for calibre) bullet in my .308 at moderate velocity and see how it behaves. This would be mostly as an exercise in reloading, but if I came up with something that worked, I might have the option in future of going after one of those hairy pig things with the tusks and the grunting, etc.
Here are the questions:
1. How good is the Miller Stability Formula?
If I use the calculator on the JBM website with numbers taken from the reloading manuals and bullet maker's websites, I can get values of around 1.6 for a 200gr RNSP or even a 220gr RNSP bullet, which suggests sufficient stability in my 1-in-12" barrel. If I change the values to reflect an ogive bullet of those weights, I get results indicating severe instability as I'd expect, but it looks like an RNSP could work. Does anyone have any experience of how much one can rely on Miller coefficients in the real world?
2. For those of you who are .308 owners / reloaders - what's the heaviest bullet you've managed to load successfully (and do you have any tips on doing it)?
I include with the question a request for anyone who's got recommendations for powder or particular bullets. Alliant is easiest for me to get and I can probably get RL17 off the shelf - I'm told this may be a good candidate?
I'll add a few more thoughts.
The first, in case anyone thinks I'm trying to do something unusual / silly / etc., is that I realise this may be silly / impractical, but I'm a curious person and I'm interested in pushing the boundaries and seeing whether I'm capable of making this work.
Second thought: yes, I realise I could just put a variation in and get a .30-06 / .300 Win Mag / .300 Weatherby on my FAC and load heavier bullets in a bigger case which was designed for them, but financially it's impractical and it will be hard to get a 300 magnum past the FEO when I'm not long into my first FAC. I'll probably apply for the Weatherby when I do my next renewal (just for fun!), or when I've got more frequent range access to justify it. Oh, and I like my .308 -another hat tip to the person on here who helped me find it.
Third: my rifle details - Heym SR20 with 24" barrel and 1-in-12" twist.
Fourth: if anyone can identify a candidate load and run it through QuickLoad to give me some idea of velocity, energy, etc., I'd very much appreciate it.
With thanks in advance to anyone who can offer some insight on this subject,