Will the new barrels used on the 580 series fit the 186 series receivers ? I know the op rod needs to be modified due to the thicker barrel but are the threads the same? Thanks.

I don't know the answer to your question but this company is sure to know.

http://www.accuratemini14.com

Check out the perfectunion forums as it seems to be the best source for info on the Mini 14.


http://www.perfectunion.com/vb/ruger-mini-14-mini-30/

The Mini barrel is not detachable from the receiver. It is all one piece.

It would take a *skilled* gunsmith to do a barrel swap, and then it would be cost prohibitive...

That's the first time I have heard that.  

I have 2 Mini 14's that have had new barrels put on by Accuracy Systems.   They no longer advertise the Mini 14 "new" barrel profile.   They do replace barrels that are similar.  I have a stainless barrel in .625 diameter on a 184 series Mini.  It made a new shooter out of it.  They also have barrel stabilizers.  ASI did not have the barrel stabilizers on hand when I had my barrels swapped.  The stabilizers look pretty decent and cost less than a new barrel.  I had a 181 series that shot 4 inches at 50 yards.  I could not get it to do better so I had a heavy barrel put on it.  The 184 series shot 3 inches at 50 yards and I had the .625 diameter barrel put on it.  The easy answer to all of this is to simply get a 583 series rifle and sell the skinny barrel rifle for what ever you can get.  The 583 series rifle is shoots much better from what I understand.

Ruger will not do it for you.   They may offer you a trade but you will have to pay almost full price unless you can convince them the gun is defective and is dangerous then they may cut you a bigger break.

kwg

Not quite true.  The Mini's barrel screws into the receiver much like most rifle barrels and with an action block and barrel clamp it's not hard to remove.  



That said, the barrels are not interchangeable so it would take a fair amount of gunsmithing to fit a new thicker barrel to the older action and the costs would make it prohibitive.  A better solution would be to buy a new 583 series Mini and sell your old one.