I finally put together a collection of accumulated parts, made a stock and configured a couple barrels.  This was a Stevens 044-1/2 action that somebody had bent the tang for a pistol grip and color casehardened.  I had a barrel I'd taken off a .22 varmint rifle, cut off the chamber and rethreaded, along with a blank I'd bought, profiled half-octagon and threaded so as to have a 2-barrel set in .22 Hornet and .17 Ackley Hornet.  I stocked the thing sort of like a "Ladies' Rifle" in order to get in touch with my Feminine Side.

The .22 barrel shoots the typical 1-1/4" and under 100-yd groups characteristic of Hornets I've encountered in the past.  The .17 is a little erratic so far but like the little girl with the curl in the center of her forehead, when it is good, it is very very good.  It's like a little ray gun; almost no trajectory between 25 and 100 yds and very little recoil.

I've only experimented with the Hornady 25 grain bullets and IMR-4198 so far.  Gone up in 1/10th grain increments.  The 10.9-gr loading (top right) is the most impressive so far, but others have clusters of 3 or 4 of 5 with one or two wide ones that might be me.  The "Sensational Seventeens" loading book allows for 14 or so grains of 4198 as a maximum loading for the Ackley Hornet but doesn't explain how you bootheel that much powder into that little shell.  In any case, about 11 grains is going to be the max for this one, due to the slope of the Stevens firing pin, which leaves a tendency for primer flow into the firing pin hole due to the "pig-nose" configuration of the firing pin that needs to be done to have it retract properly.

I haven't blued the .17 barrel yet, which is why it's "almost done."  It seems like once I get something into shooting shape, I get less and less interested in the push to the final finish. I have a bunch of barrels that I need to do a gigantic Rust Blue-A-Thon on one of these days.

By the way, for anybody thinking of bending a Stevens 44-1/2 design tang for a pistol grip, the relationship of trigger nose to sear bents changes and I experienced some trouble getting the thing to cock and shoot for a while.  Hopefully, that's all behind me now.

The scope is a MVA copy of the Winchester A5, which gives the thing a nice "period" look.

BR,
I dabbled a little in this Ackley cartridge and getting those kind of charges puzzled me too.  A long drop tube and later touching a case to the Vibra-mill just to see if it could be settled without compressing, a no go...    Looks like the 10.9g is favorable in yours.  The brief notes I found for mine were with the use of both 4198 IMR and H4198.  They're different in density, shape and burn - if I remember correctly.  My notes say at 12.5 grains even the H was compressed.  Somehow I got distracted and never made it back to this project, imagine that... 
Mine was in a small shank HW and I haven't spent any time with the Stevens, appears that you're gaining.   
Thanks for sharing.
Greg