Recently bought a G47 and picked up a Glock 1/2-28 threaded barrel for it. Already had a G34 Gen4, G48 and G43x in 9mm. After breaking it in for about 500 rounds, I tried it with a couple suppressors. Worked fine with factory ammo and 147gr. loads with slower powders like CFE Pistol and Autocomp. However, quieter handloads like a 147gr. with 3.4gr. Titegroup would not lock back on the last round. 165gr. Xtreme with 3.0gr. Titegroup wouldn't even eject (betting it would also struggle with 165gr. Hush). The G34. G48 and G43x run these loads flawlessly with their factory recoil springs. G43x and G48 have factory triggers. G34 has a Timney Alpha trigger.
Tried breaking in the G47 more with a few hundred more rounds. Cleaning it really good (complete strip down), re-lubing it and even over-lubing it. Still not dice with the Titegroup loads. Bought NDZ 15 lbs. and 13 lbs. recoil springs. The 15 lbs. improved things a bit. Got it down to the odd failure to lock open with the the 147gr. load and the 165gr. load would eject, but not lock open. The 13 lbs. recoil spring wouldn't bring the slide back fully into battery. It would pick up the round and push it into the chamber, but it the barrel was still tilted and not locked up.
I finally gave up on the G47. It worked fine with factory 147gr. ammo, so I couldn't sent it to Glock for warranty. But, it irked me that it wouldn't cycle quieter loads that work in all of my other 9mm Glocks. So, I traded it in for a G17 Gen5. I put the same Glock threaded barrel in the G17, gave it three mags of break-in and then tried the Titegroup loads. G17 works flawlessly with the Titegroup loads like of my other 9mm Glocks!
Just thought I would share the experience for those considering the G47 as a suppressor host if they plan on running some of the quieter subsonic handloads in it. Maybe I just got a lemon(ish) G47, but I'm guessing the shorter recoil spring and slightly heavier slide are a factor. I don't know, it's only a sample size of one.