I have the same issue in both my C and CA, though curiously after about 400 rounds the CA reassembles faster than the C, which to date have never been fired since I bought it a year ago. (I forget about stuff like this, I'll go and pick up a gun that arrived, but if I'm still tinkering on a problem with another gun they go unnoticed after the arrival cleaning until I get to it).
For me, the trick is to assemble it with the gun upside down, let the bolt travel forward a bit and hold it there using the dust cover. For me my bolt gets snagged on the little metal bolt hold open plate more often than the rivet.
Sometimes, assembling it vertically also helps too. Over time you'll get the hang of it, it's not as complicated as it seems, just have to fiddle with it. If it's too frustrating, put it down, grab a beer, then try again later. They run pretty clean.