Welcome Aboard !Suggestions...
• CZ barrels will shoot 115gr very accurately, but the twist rate favors 124gr. Saying this I note that member
JoeL shoots 115gr at 100yds with outstanding results.
• Jacketed bullets will give much more consistent results over Lead or Plated. Bullets from
Zero,
Precision Delta and
Rocky Mntn Reloading (RMR) seem to be the preferred vendors. RMR is advising that they currently have 124gr jacketed in stock.
• In RMR you can either go with the JHP or their "
Match Winner". Both get rave reviews. If you are wanting to try some 147gr, then their
147gr Match Winner is one of a handful that can successfully negotiate the CZ barrel. (But you'd need a slower powder than W231 for 147gr.)
• In case you didn't know, W231 is the exact same as
Hodgdon HP-38. So often you won't see loads listed for both in your manual, and that's why. You simply need to know that bit. If you need to replenish, then HP-38 is usually $1 less expensive (at least in my area).
• Looks like W231 has about a 1.2gr load range for 115gr.
I know you're just getting started, but a better test would be 6-10 at 4.4gr, 6-10 at 4.6gr, 6-10 at 4.8gr, and so on. You'll not only see the velocity climb, but the POI climb as well.
And you'll also see the groups tighten up too. The
lowest load with the tightest group is the one your gun loves. From then on there's really no reason to load anything else as long as you're loading
those bullets with
that powder. Change bullets or powder and it starts all over again.

• W231/HP-38 is a genuinely great powder for the novice. It's wide load range makes it VERY forgiving of small beginner mistakes, and it meters like a dream. I'm glad that's what you ended up with. Soon you'll have some other powder choices, and I would suggest something slightly slower for increased accuracy. Maybe BE-86, N340, Power Pistol, Silhouette, or such.
Not Unique because at this point it's truly outdated.
• If you 'll use a target like the TQ-2, then they are small enough to store in a recipe box. You can compare targets from 10 years ago and find out if today's powder is any better. Pretty handy. Get them from
National Target Co.
https://www.nationaltarget.com/index.php
• Lastly I'd like to
insist that you get a notebook of some type for keeping your own personal notes. Loose leaf, spiral bound, hard bound lab notebook.... your choice. I like to reserve a new page for each individual bullet. This because the OAL is tied to the bullet shape. You may shoot two 115gr lead bullets, but they could load at different OALs, which would change the optimum load. It might also change die settings and a host of other "lessons learned" as you go. Besides it's just nice to get an order of bullets in that you haven't used in 3 years, flip the notebook open to that page and everything you need to know is right there. Might look like this....

At the top of the page all the important bullet information and die settings. Then all the loads with different powders and follow-on information.
And be sure and read our
Stickies on reloading at the very top of the page. Indispensable info there.
All the best.
