More detailed to follow, but quick and dirty.
Act Mags showed up today, feeding problem solved. Weather and work conspired to limit what I could do, but I snuck out for 1/2 hour to run some rounds. Windy as all get out and spitting rain, I got tired of standing my target stand back up so no accuracy report. I'm beyond rusty with a pistol, but until I gave up on the target grouping was pretty decent. After that I just ran rounds into the hillside to check brass.
I did 3 loads from min to max using longshot powder and standard pistol primers. 230gr xtp's loaded as long as I can get to work in the magazine, they could probably go a bit deeper and smooth out the mag feed a bit. I did probably 50 rounds in short order. None showed any signs of pressure. It did show that I need to fix the ejector timing on my pistol, no surprise there and the case mouths can be fixed
Ejection is up there, I'll be looking for 1/2 dozen brass next time I'm out there. I ran out of time so there's a few in the field. On the + side I found a box of .308 brass to make up for it.
I had regular FTF with the 1st round if the mag was fully loaded. Taking it down to 6 rounds solved that problem, I assume it will smooth out once the mags break in. The mags that go through clarks have a stiffer spring than what you get straight through ACT, might be the reason. Beyond the 1st round on a full mag it fed well.
Even with max loads, it's pleasant to shoot. The combo of the suppressor and heavy spring pull a whole lot of energy out of the recoil. If I had to guess I can probably do 2 rounds in the same amount of time I can do a similar load in 44mag. I'll do a comparison next time out and see how fast I can run it. I'll take out one of my .45's also to compare recoil. If the .460 is worse than the .45, it's not by much.
I doubled up on ears, plugs and muffs, and I hate muffs. But the amount of energy I'm assuming is coming up out of that comp I think it's a good way to go. I might change later and go to straight plugs.
I'll be tweaking the pistol before too long, it had timing issues out of the box. It's pretty common with the GI model from what I've read but since it was a shelf queen I never saw the need.
If long term is as good as short term testing, I'm pretty pleased with the combo.