Bummer, 4.0gr would function in my 1911, took 4.2gr HP38 for my P226 and XD Compact+Subcompact. to get 100% function.
I would have thought 4.6 would have been more than enough.
4.2/4.3 worked for me/Doublehelix and vaalpens in different guns, but of course all guns behave different.
Yes, all guns are different and this one needs 4.8 gr of W231 to cycle.
Is the gun new/low round count? (spring that's in it still stiff)
Got somewhere between 1500 and 2000 rounds on the clock.
Yes, Hodgdon's start charges are quite a bit higher, but it sort of defeats the purpose of using the 100s if you need to push them to 1200 to get function. (120PF)
Hard to say when they wouldn't function but if you liked the feel (lack of muzzle flip) it might be worth getting a lighter spring for SC.
Wolff has lighter springs
https://www.gunsprings.com/SPRINGFIELD/XD 5 INCH/cID1/mID60/dID271
Lighter springs from 9lb to 16lb in 1lb inc.
Might give them a call and see if they had a suggestion on how light you need to go.
I don't own a XD 5" but guessing (just a guess) you might try backing off a couple lbs to 15.
Springs look like they at $7.95 from Wolff but by the time you pay shipping it might be worth your trouble to order 2 different ones, say maybe 15 and 13.
I ordered a 13lb spring, with hopes that the 4.2 gr loads will cycle. We'll see. I'm having fun trying all this stuff out!
Is the gun new/low round count? (spring that's in it still stiff)