Have you tried putting the BYF trigger into it?
Might answer the question.

or vice versa and see if the problem is present with the "bad" trigger in the byf?

Did you say you were a pilot?

SZ, You may want to try one of my new, stiffer, Mauser Parabellum trigger springs @$5 + $3 S&H. It's also possible that your trigger is "clicking" on the frame at the front, in the area where that your index finger is covering inyour top photo. Tom

Is the 1918 "trouble trigger" numbered to the frame, or a misnumbered part?? What does your trigger return spring look like??

hmm, it's possible! definitely sending you a PM on the stiffer spring. what's odd about it is that it only clicks when the trigger isn't pushed all the way back in the well.

yes sir, it is numbered to the frame. the return spring appears to have thinner coils than the byf and definitely is much weaker.

ya the video is with the BYF spring and it makes the trigger movement side to side less sloppy BUT it's still sloppy and still makes the clicking sound. and yes sir, I am indeed an airline pilot

promoting those negative pilot stereotypes :mad: however, I laugh every time I watch that :thumbsup:

ok so for anyone still here, I narrowed down what's going on with the BYF hold open issue and brass issue
I did some swapping of various parts from one to the other and came to the conclusion that the bottom half of my BYF is the cause of the hold open issue while the top half is causing the brass shavings problem. not sure what half is causing the empty brass to get caught between the bolt and the breach

Last problem may be ammo or magazine related.

Does the combination of the two "good" halves work well?

Could be for the ammo; It was maybe 10 year old WWB with newer mec-gar magazines but it only happens with the BYF

The half with the BYF bottom had the same exact issues with the 1918 DWM top

The half with the BYF top and the 1918 bottom didn't have an issue cycling or staying open on the last shot BUT the sear bar tab thing would not **** after each shot so I would have to rack another round to get another shot. I ended up just putting one bullet at a time in it and it held open after every last shot BUT would still dent brass and send shavings everywhere.

James, you can narrow the shavings situation to one side or the other. It is data, and may help.

Since you're one-shotting it anyway, mark each round with a Sharpie and insert it with the mark in a consistent place--say, 12:00. You can then chase the empties and be able to see the damage's relationship to the mark.

Let's see a pic of a typically damaged case!