A little digression first on full auto Mini14s. While based on the Ruger Mini14, many parts from the AC556 are not interchangeable with the Ruger Mini14. For one thing, the receiver of the AC556 is different from that of the Mini14. Besides the obvious cutouts for the selector switch, receiver of the AC556 is slightly longer. There are a few other parts on the AC556 (trigger, secondary sear, trigger housing to name a few) which also won't fit or work with Mini14 parts.
Concerning converting a Mini14 to full auto, I believe it can be done. Paladin Press sells a book which I've studied and the suggested modifications are very similar that of the AC556, sans the three shot burst feature of the AC556. Modification requires some drilling & tapping on the receiver (and even without the full auto parts installed, is easily recognized by a trained LEO as a converted firearm), fabrication of a rocker arm (trip lever for link) and a few other parts. Since it's illegal to convert anything to selective fire unless its for the military, law enforcement or for export, it is better to follow the legal channel and purchase a real AC556 from a Class III dealer.
Concerning the plastic 90 round drums from MWG, they work. One would think that because of the design, the balance of the Mini would be thrown off. While it is appreciably heavier, it's not lopsided at all. It works, is fun, but don't shoot too fast unless you're willing to send it back to Ruger for rebarrelling.
Finally, Heavy Barrels from the factory. I remember seeing the heavier Mini30 barrels bored smaller for the .223 when I was at the factory in 1996. Bill Ruger wanted to make his Mini14 more accurate and sent one gun to TX for accurizing. The engineers at Ruger studied the modifications and found them to be cost prohibitive for production and from a sales prospective, difficult to recover costs (the modified gun had a heavy varmint barrel, trigger work, glass bedded action and probably some other things which I'm not aware of). As an interim, a batch of stainless Mini14s with the heavier Mini30 barrels were made. While I was told that all new Mini14s would have these heavier barrels, I haven't followed up on it and it's been two years now. As you know, the heavier barrel would flex less due to heat warpage.
I was talking to the assembler at the factory who told me that he could get the barrels to shoot 2" MOA by mere straightening. After the barrels and receivers are assembled, they are placed on a jig which measures the straightness of the barrel and receiver. If it is over .004", he places the assembly into another jig to which an arbor press is attached, and tweaks the barrel. The assembly is then remounted onto the first jig and measured again. When he gets it to within factory specs (which should give 4" at 100 yards), the assembly is placed on the rack and another is tested. Mind you, a lot of other assemblers contribute to building the Mini14 and if they tweak it, his work is ruined.
4v50
[This message has been edited by 4V50 Gary (edited 12-22-98).]
