I am running a stock CCG kit with the exception of the (extremely light) ISMI 14CS - 14 lbs, chrome silicon recoil spring in my Colt XSE SS Government with no buffer.
Ask gorknoids or utf59 if either felt like the gun's timing was anything other than smooth and "Colt Like"
I have no worries nor have I witnessed ANY
accelerated wear/peening on the recoil rod/link/frame or anything else. (Your concern must be with the S&W because the Colt is doing fine.)
I have ran everything from Georgia Arms 460 Rowland 185gr JHPs, 230gr Speer Bonded Unicore JHPs to Cor-Bon Hunter 255gr JHP BC (Bonded Core).
Also I have ran (With no issues) both .45 ACP ball, .45 ACP JHP in standard and +P loads.
Hell, friends and visitors have shot over 300 rounds and I've doubled that with 80%+ using the ISMI 14# spring.
I think your $90, Sprinco Recoil Management Guide Rod System is a solution to a non-existent problem. (At least in my Colt.)
If anything should be of concern IMHO, it would be your S&W's external extractor, another solution to a non-existent problem. (At least in my Colt.)
I applaud your effort to revisit the 460 as a one-shot-stopper. Keep us in the loop.
I understand Buffalo Bore Ammunition Co. plans to introduce four or five 460 Rowland loads in 2011. WOOT!!!
Buffalo Bore Products Coming Soon