Old gun new ammo

I have a beautiful Colt 45 ACP done by an Army armorer from this area. It was built around the 230G ball ammo.
I want to run something along the lines of 185G JHP with loads of 4.0 to 4.4 B/E.
Would a recoil spring change to 11 lbs be a good start ? Anything else I should look at ?
TIA  Ron

11 is probably too light.  Try it with the stock spring (usually 16) first.  My ball gun cycles the load you are interested in fine with a 16.

I am having issues right now with it not cycling a normal bullseye load without jacking the contents up to 5.0, which is why I thought the spring was in there from the factory 230G ball ammo ?
I just got a so called spring tester from Lyman, I will start to measure all of my springs so I have a reference on my tool only.

You would be better off starting with a heavier spring like the 16 pound Don suggested and work down if not cycling. Too light a spring will cause the slide to come back too hard. Why hammer a good gun? I like to use the auto lock back as my gauge. Select a spring that will not lock the slide back and lower until it does.

If you have a spare firing pin stop, file/sand a nice radius along the bottom; that will help the light loads cycle as well. Squared firing pin stops are great for taming hardball but make the gun harder to cock and cycle light loads. Just set the stock FP stop aside along with the recoil spring.

OK, so tonight I measured the the spring in the gun on MY little tester. 15.8 lbs.
I then measured a couple more wolf springs I had and found an 11.9 lb spring and installed it.
I looked at the firing pin stop and it is way radiused to almost a slope to the hole.
Took some loaded ammunition and went to the range.
The gun has a stout but manageable recoil at 4.8 g WST and a 185 g SWCHP ( outdoor load ), very nice feel/recoil with down to 3.9 of B/E with the same bullet.
The gun now functions/cycles fine, I even threw a couple of five rounds in with a copper plated flat nose 185g and it all worked fine.
I need to figure out how to change the trajectory of the cases, every second round landed on the top of my head ! Its a ball gun so I cant do too much externally.
Thanks for the tips.
Ron

Wear a hard hat.

Everyone wants to be a comedian, you need to keep practicing !

I’m here all week.