The only time I was able to get hold of a chronograph for a good testing session I clocked the 2.5gr 231 load behind the 35gr V-Max at 1850fps average velocity from the 22" barrel of the converted M-1969 Romainian trainer.

On the same outing
Blue Dot resulted in 1300fps
Bullseye -1750
Clays - 1475
Unique - 1262

Since then I've set up a balistic pendulum, mainly as a comparitive tool for testing different powders.

I'll have to find my notes on the loads but near full case loads are pretty much the norm with the soft Hornady bullets in this small case.

As a baseline the same 231 load caused the pendulum to swing 22-1/4"

2.2 gr AA Nitro 100 resulted in a 21" swing(1750fps) and looked to be fairly uniform for all shots. I really want to get hold of a chrony again with this load.

1.7gr 700-X resulted in a 17-1/2" swing (1433fps)

1.8gr 800-X only managed an 11" swing (900fps) which surprised me.

4227 resulted in 3 out of the 5 shots tested not clearing the barrel. the other 2 shots were visible from the muzzle to the spot 50-75 ft downrange where they fell to the ground.

I've function tested the 33gr V-max, 40gr Hornady .222 Jet flat nose (which looks pretty neat), and the 45gr Hornet. All showed no pressure signs with the loads worked up.

The 45gr Rem HP on the other hand could NOT be used with any load without blowing primers. Apparently the effort to push a .223/.224 bullet into the 0.221 rimfire bore of this rifle makes the round real sensitive to jacket and or bullet hardness.

I'd like to get hold of some of the 30gr, 25gr, and I've even heard of some 20gr 22 varmint bullets. The small case should like those. Though I suspect the squirrels won't be too fond of them.