You will be very lucky to find a gunsmith with much experience with the old ruger carbine. Even back in the day most wouldn't touch it because it was like working on a swiss watch.
At some time the gas port will require cleaning for proper functioning. This is a job most owners don't or can't do as it can be tedious. The gas port is about midway down the barrel and covered up so you must disassemble the rifle to get to it. This link shows you how to do this. https://www.alloutdoor.com/2017/10/04/24-photos-ruger-44-carbine-disassembly-cleaning-assembly/
It's a pain but neccessary, we once had several of these carbines and I've done it numerous times but never enjoyed the experience.
These little carbines are usually quite accurate. I have an Aimpoint SC1000 red dot sight on mine and at 50 yards most shots are touching each other.
Most accuracy problems are usually the result of the terrible trigger pull. Extremely heavy, long and gritty. My wife couldn't hit a cardboard box at 50 yards due to the trigger. No gunsmith I called would touch it. So being young and fearless I used the schematics to access the neccessary trigger parts and honed the surfaces smooth with a hard 3/8's arkansas stone. It made it shootable but not great. I ended up doing 3 of these trigger jobs. You must be real careful here not to turn your carbine into a fully automatic. I was only after smoothing out the tool marks and rough spots, not reducing trigger pull.
That was a long time ago and I wouldn't know where to start now but I'm relaying this info to let you know it can be done.
A quick google search on "Ruger 44 carbine trigger job" turned up a lot of hits, most were from people wanting to know how to do it, but a few looked promising, you might want to check them out.
The old man at Bullseye in downtown Lawrenceville can do it for you. He’s still there after 25 years. Nice guy. I just ran into him the other day.
I took mine there and left it with him and pretty much an open ended check to fix it. He called a week or so later and charged me $40. He said it was the gas system. The gun is still flawless ever since. Before that it began to jam after the first shot and eventually always jammed. My cleaning and oil didn’t help. He fixed it. Hasn’t jammed since.
Once that gas port is clogged no matter how much oil you use, or how often you brush out the barrel and chamber, the jamming just gets worse.
$40. sounds reasonable if you don't care to tackle it yourself. Maybe he will polish that trigger for you also.