Triaxle, good on you for resurrecting an nice old 182 Mini ( and a 6 year old thread).
I should hope you could hit a 3 to 4 foot target at 250 yards.
My groups at that range, with a rest, average 3 to 4 inches, and you don't necessarily need a scope to do it. This was shot with a Burris FastFire red dot.
If your Mini ejects 30 to 40 feet, I'd suggest a smaller bushing to get that excess gas down. Like a .045" one. And some Wilson 1911 buffers.
Get a two clamp Accustrut for that pencil barrel 182, and do the dimple mod on the set screws.
If you really want to see some good accuracy out of that older Mini, lop an inch or two off the barrel, recrown it and thread for a flash hider ( or use a Choate pin on).
If your's is a non Ranch model, they tend to eject more straight up and make mounting a scope or dot over the action more difficult. Plus you don't have the intregal scope bases of the Ranch or rail that the new Mini's come tapped for.
For those the Ultimak railed handguard is the best and easiest way to mount an optic.
And if you don't reload, try several different brands and weights of ammo, don't be discouraged if your Mini doesn't do well with the first one you try.
You can look at a chart like this to determine what twist your Mini's barrel has, looks like the 182's had a 1-10" twist. So your's with probably do better with bullets in the medium weight range, 55 grains, plus or minus 5 grains.
https://rugerforum.net/ruger-semi-a...14-30-manufacture-date-twist-rate-update.html