Sorry, haven't chronographed the 50gr load.
My Nosler 40gr and Hornady 35gr V-Max Lil'Gun 13.0gr loads were doing around 2,900fps.
I haven't used AR2205 in my Savage Model 40 yet, as I started on Lil'Gun, as soon as I got it.
I'll get around to it one day, maybe, but potentially, the pressures will be higher, using 2205.
I'd hesitate shooting a 50gr with a full load of 2205. Might do some damage !
I was using 11.3gr AR2205 (H4227equivalent) in my Brno Fox with the 35gr's, but as the barrel/chamber was stuffed, the results weren't spectacular.
The best I had was from factory Hornady V-Max.
They were doing around 3,000fps, as the box says.
The factory loads have a cannelure and crimp, which seems to bring a bit of consistency to the neck hold on the little projectile.
I've noticed that the same projectiles over the counter aren't cannelured for crimp.
cheers,
Sean in 'Godzone'