NateCowlisha:
1)The Ruger "Six Series" revolvers(Security/Service/Speed-Sixes) are some of the finest service revolvers ever made! All three of these guns are identical mechanically. Aside from different barrel lengths(And, weights: Std vs heavy barrel) and caliber, they differ only in the following respects: Note: This, and the following information applies to the new frame "Sixes" which have #151 and up serial number prefixes. The old frame design had the #150 s/n prefix with a scant few "transitional" guns with the old frame design that were produced and marked with the #151 s/n prefix! The old frame design mostly, just had a slightly different grip frame
and, with the upper rear of the frame changed to remove the
downward slope of the frame at the base of the hammer. Otherwise, except for the different(And, harder to find!)older grips, for these early #150 s/n prefix guns-they are the same as the New frame "Six Series" revolvers! All are great revolvers-strong, durable, reliable, and were designed from day #1 to fire the standard .357 magnum rounds! Over 1-1/2 million of these "Six Series" revolvers were produced from(1971through 1988)however, the Security-Six was dropped first, in 1985. Both the Service-Six and the Speed-Six continued on until their final production in 1988, to service the police market and for special Ruger contracts!
a)Security-Six has adjustable sights and a square butt grip frame.
b)Service-Six(aka: Police Service-Six)is identical to the Security-Six-except for having the "fixed sights" instead of adjustable sights. The square butt grip frame is the same as for the Security-Six.
c)Speed-Six is identical to the Service-Six-except for having a round butt grip frame profile!
2)Grips: Factory Ruger wood target grips are nice and are seen on ebay occassionally. If you purchase aftermarket grips then, as long as they are indicated for serial number prefixes of #151 and up, you will know they are the right grips to fit your Service-Six! Below are some links to some ebay grips that I'd selected out for you to check out. All of these will fit your revolver:
Factory Ruger wood target grips:
http://cgi.ebay.com/RUGER-SECURITY-...462?pt=LH_DefaultDomain_0&hash=item563fa9320e
Herretts Wood target grips:
http://cgi.ebay.com/Herretts-Ruger-...080?pt=LH_DefaultDomain_0&hash=item45f68fb718
Jay Scot wood target grips:
http://cgi.ebay.com/Jay-Scott-Grips...103?pt=LH_DefaultDomain_0&hash=item518cbcfa77
Aftermarket rare rosewood grips:
http://cgi.ebay.com/RUGER-GRIPS-RAR...927?pt=LH_DefaultDomain_0&hash=item2a0b8948ff