Well, I bought two 3-D printed silencers from Buck Rail, one for my Crosman 1322 and one for my Crosman 1377. Each one came in two pieces, something to fit onto the end of the barrel, and then the silencer, which screwed onto the piece on the barrel. It sure looked good to me. BUT IT WASN'T.
Neither was a good fit (both were too tight), but the one for the 1377 was flat out awful. I had installed the one for my 1322 first and used the palm of my hand to press it on. And thought all was going to be good and it seemed to work well, for a while. I'll get to that later.
But the one (both silencers are the same) for the 1377 was an awful fit, Against my better judgement, I used a rubber hammer to lightly tap it fully into place on the end of the 1377's barrel. But in doing that, the barrel must have shaved up a piece of the silencer's plastic inside (I could see it, later) and the 1377 never shot accurately again - didn't even hit the target, from about 7 yards away. And It was the dickens to get it back off. Well, shortly thereafter I went to shoot the 1322 and nothing came out. Somehow the 3-D printed silencer had interfered with that gun's pellet, too.
So, I have removed both of the 3-D printed silencers and the guns are "stock" again and shooting well. Getting the thing off the end of the 1322's barrel was no problem, but getting the one off the 1377 was a pain. I ended up removing the barrel so I could get some leverage, used my heat gun and eventually got it back off. What seemed like a good idea at the time didn't turn out to be. Both 3-D printed silencers are in the trash can, now. I'm gonna just leave the two pistols as they are.