H100V is a very useful powder in the 243Win, depending on the weight of bullets you're going to shoot.
I find it very good for bullets 90 grains and under and get great velocities/accuracy.
However, there can be a bit of an issue with spiking pressures when using 100+ grain bullets. Once you reach the middle range of the loads suggested in the manuals, you may start getting sticky bolt lift after firing.
One thing I've found, this powder doesn't like to be compressed. Velocities start to get erratic. Not sure why. I've tried CCI 200 and CCI 250 primers and got the same results.
I tried it with 105 grain bullets as well but IMHO it's a bit fast.
Here's what you really need to know.
H100V WILL give you satisfactory results with the bullet you mention. Just don't push its limits. Of course, that can be said about any powder.
H100V was designed as a powder that would be useful over a wide range of cartridges. It isn't really perfect for anything, there are other specific powders that will do specific jobs better. The thing is, it will perform 90% as well in everything it's useful for.
If you shoot several short action and even standard length cartridges and want one go to powder, H100V will be a good choice to have on the shelf.
