There has been a lot of interest expressed in this conference about
modifying 10/22's.  The Aug 96 issue of GUNS magazine has an article
titled RIFLES OF THE AMT CUSTOM SHOP.  The author is the well-known
competition shooter Mickey Fowler.  Apparently, AMT makes a 10/22 clone,
or at least a very similar rifle, to the 10/22, but with a stainless
steel receiver in place of the 10/22's aluminum one.
Fowler compares the two materials:
BEGIN QUOTE ***********************************************************
The heart of any rifle is it's receiver.  The AMT receiver is
manufactured from 17-4 PH (precipitation hardened) stainless steel.  The
bolt and trigger group are also made from this tough,
corrosion-resistant material.
Match rifles use heavy barrels which put a lot of stress on a receiver.
The strong steel receiver allows the barrel to be threaded into it.
This is a superior method of barrel attachment that is stronger, more
precise and allows proper bedding of the action in the stock, which is
essential when building an accurate rifle.
Many Ruger 10/22 rifles have been converted for use in the Chevy Truck
Challenge Match.  Constant use of these rifles has pointed out the
weakness of the aluminum parts.  The barrels, with few exceptions, are
slipped into the aluminum receivers and pinned.
Problems have become evident as shooters have reported cracks developing
around the ejection port.  Steel locating pins in the Ruger 10/22
trigger group eventually become loose from the constant pounding,
causing trigger pulls to change.  Although the 10/22 is a good rifle, it
was not designed to be converted to a heavy barrel match rifle.  The AMT
stainless steel receiver and trigger group are far superior for match
rifle or any extended heavy use applications.
END QUOTE *************************************************************
Regards
John
--- WILDMAIL!/WC v4.12 
---------------