First off, it is a custom made Ruger MKIII (without the magazine safety) that is very well machined. The barrel is an insert of sorts that is approximately the same diameter as the bolt and is securely mounted in place inside the aluminum upper. Technically my gun isn't a Scorpion as mine is a parts gun that was fully assembled into a scorpion over time. As far as accuracy goes: I shoot in Bullseye competitions where accuracy is the primary concern. If you're not familiar with the sport you shoot one handed at 25 and 50 yards with a set time limit.
The gun works extremely well as it is extremely accurate and reliable. I don't shoot many guns well at 50 yards but this one makes 50 yard shooting easy. On a normal day it will easily shoot inside the ten ring with many in the X-ring of a B-8 NRA/CMP target. Of course the .22LR cartridge is inherently very accurate so as long as the barrel is made by someone who isn't a 'tard it will be very accurate. I have linked a video below showing off its potential capabilities at 100 yards. It only shows a five shot group but it does illustrate its consistency and accuracy fairly well.
If you already have a Ruger (with a full steel upper) and you are worried about accuracy you could send it off to Ten Ring Precision to have the barrel re-lined which will likely up your accuracy slightly.
http://www.tenring.com/ruger-mark-ii-govt-model-rimfire-22-accuracy/ This is fairly common with older .22's or with existing guns needing more accuracy. Additionally, you might contact Volquartsen or Clark custom as they may offer to install one of their ( both excellent) barrels.
Here is a picture of mine. I added the 3D printed mount for the Brass weight as it wasn't heavy enough for me. The grips shown are also no longer on the gun as it is currently getting some newer better fit to my hand grips made.
This is not my video, but the accuracy of these guns is really excellent. This is 50 meter free pistol level accuracy at 100 yards!
Skip to 52 seconds to see the test.
Good luck with whatever you decide!