I sent this to Wolff Gunsprings today, let's see what will come of this?

Hello,
I have purchased many different springs from you guys in the past, great work.
Now I have an odd request.

I have your springs in many, many firearms.
Including one mongrel in a EAA Wittnes-P 10 m.m. full size and it handles my NUCLEAR Reloads PERFECTLY.

I have three Marlin Camp carbines, two 9's and a .45 ACP with your 16.5# and 21# springs in them.
Great stuff......
I converted one of the 9's into a .356 TSW and used your 21# - .45 ACP spring, works perfectly.
(Paul Liebenberg of the old S&W Performance Center now Pistol Dynamics in Florida, said he couldn't make his work.)

I have also converted (with your springs) a S&W 6906 to .356 TSW with a barrel that originally came out of the S&W Performance Center as a test barrel.
A S&W 5906-.356 TSW, again your springs and I have also converted a Walther P99-9 m.m. using a S&W P99-45 recoil spring, just had to make the encapsulated recoil rod.

Now,
I also have three Ruger PC carbines, two 9's and a .40 S&W with some extra 9 m.m. barrels.
I'm working on converting one PC-4 into a .357 SIG, the stock .40 spring should work in that one.

But here's the one that I'm looking for some help with,
I'm working on converting the other 9 into a .356 TSW and need a stronger recoil spring.
Ruger uses the same spring in both the 9 and 40 carbine, they rely on the extra bolt mass to dampen the recoil of the .40 S&W.
As I suspected I do not see anything listed because of the nature of their carbine is pretty fool proof by design.
I was wondering if you could recommend any spring stronger than the stock PC-9/40 spring that would fit this application?
Or, could you give me the specs on the SKU 16800 for the Ruger .44 Magnum Carbine, XP Recoil Spring.
Or, I could get a new spring from Ruger and pass along all the dimensions for you to compare to your springs by dimensions?

I am a retired Aerospace CAD/CAM/CNC Manufacturing Engineer/Plant Manager.
I am doing all the chamber boring, turning and threading and milling in CNC equipment,
adhering to ANSI chamber specifications and standard SAE and JIS thread specifications.

Please advise, (HELP)
Thank You,
BM1