In my model 70 Winchester .223 Rem I used Win 231 powder. 2.65 grains was my slow load and 3.3 grains my fast load. Both very accurate out to 50 yards, about dime size at 50.  

It’s a NOE 55 grain mold with 2 plain base and 2 gas check cavities an Egan shape bullet. Accuracy was the about same with either and the gas check bullet shot the best without the gas check.  Lube was Lee liquid alox. Never tried to shoot the at around 2000 fps or faster.


I wanted the slow load to shoot raccoons out of my upstairs window at night but it was a bit too loud.  It was a raccoon family affair virtually destroying my bird feeders. They needed three caskets one night and they quit coming to my bird feeders.

.22 Hornet, I will say it's hard to beat Lyman/Ideal 225438. Be aware though that there are at least four iterations of that mold over the hundred years or so it's been in the lineup, per the examples in my hands - small subtle differences but different nonetheless. As a general rule fast pistol powders rock for use in the Hornet. My go-to load is 225438, gas checked, 1:20 alloy, 50/50 lube, 2.0gr. Red Dot, for around 1200fps. Roughly MOA accuracy out of Browning Low Wall (when sized .2245"), 1 1/2 MOA out of Stevens 44 .22 WCF (unsized as-cast .226").

Ideal #225230, 45gr. plain base, has proved to be pretty finicky. Best results for me for Hornet use are with 1:20, 50/50 lube, and 1.8gr. Bullseye. Accuracy not at par with 225438, but not bad - 2 MOA on average. Slated for more work this season.

Another favorite, for a bit more zip, is the Lee Bator 52gr. blunt round nose (which I think is discontinued but pops up in the used market occasionally). It's a short blunt GC'ed bullet that stabilizes ok in 1-16" barrels, about same length as the 45gr. 225438 - at least my mold cavity is. I cast them hard, out of lino/pure lead 5:4 ratio, sized a bit differently depending on which gun, 50/50 lube, 6.0gr. 2400. Frankly I've never chrono'ed it but it's snappy - right like a .22 WMR. Dime sized groups @ 50 nickel-quarter sized at 100 out of both my M54 K-Hornet and kiplauf 5.6x35R.

One final comment: I get better accuracy with all the above mentioned loads when using small pistol primers. In some instances the difference is dramatic versus using Remington 6 1/2 primers (which are my go-to's for full snot jacketed loads - 40gr. Vmax + 13gr. Lil Gun, 3100fps).

Any way you cut it, Hornets + cast loads = cheap shooting.

OK, I've got at least 6 other moulds.  225438, 225415, and 3 three-cavity moulds from someone.
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QUESTION:  When seating cast bullets in the Hornet(s) or the 223, what techniques do y'all use for consistent accuracy?  
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I can make my own expanders, to fit the Wilson holders.
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I've sorted 187 Winchester cases for this project.
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AND I'm assuming that the Wilson straight-line seater won't work with cast as cast bullets are larger in diameter than J.

My .22 centerfire is a .22 BR. The mold is an NOE that weighs 80- grains +/-. The case starts as a 6 BR. Powders that I’ve tried are WST, 4756 and Tite Group. Have thought about trying some VV powders. No chronograph data yet. Barrel is a 3-groove Lilja, 8 twist.

Tom

NOE has copies of two Eagan molds in .22 I sent him a few years ago.They are tapered bullets (looking like a mini SAECO #315) and shoot quite well.
MX3-22 and MX3-22 EX.
Contrary to common opinions 22 bullets are as easy to cast as any other caliber and ultra picky weight sorting not needed.
The tiny GC is the annoying part installing. 

When i first started loading cast in my Shillen barreled Borchardt, I tried just about every mould  I could get my hands on.  Couldn't find consistancy until I cast up original Ideal 22636 60gr. from an original Ideal integeral handled mould.  These were chucked up in bench lathe and faced to 50grs.  On some I turned ...bite my tongue!..gas check shanks.  These prooved to be the most accurate bullets so far.  I had Fred Leeth make up nose-pour molds in both gas check and plain-base in same weight.   
    Took me about 5 years of constant tweaking but I was able to equal best match accuracy with match grade jacketed at 100yds...not every time out of course, but enough to know it wasn't a fluke.

another small step.
Using an old expander from decades ago; it  I just tap the expander into the sized case, I expand just enough in diameter/form/and depth to place the  bullet into the case.  Bullets measure 0.255" dia. (calipers, not micrometer).  Tumble lubed, not sized.