What is it for?
 

"SOLD"Brian and I are just starting to clean out the Chicken Ranch as it is being sold. I must decide what to bring home and what to get rid of. I know this is a brass catcher but I don't know what for so have no idea of value. Canvas is nice and zippers work. Dated either 1960 or 1968.
Barry

It goes on the SMG mount of the side of the M38A1. If parting with it PM or call me. I have spare arm that is missing this piece...Brian

Brian of course meant to say GPMG rather than SMG. There were two bags along with the little funnel shaped bracket seen on yours. The other bag was on a large U bolt mounted under the gun. One caught the links and the other caught the brass. They filled up very quickly.

I have the modification/installation instructions for these if anyone wants to see them.

Thanks Rob. That would explain why the funnel doesn't line up with the bag. I have the bag with the U shaped bracket but it looks like I am missing a bag.
Cheers,
Barry

The two bags were a different size, but not nearly big enough. I doubt you would get through a 1/4 box of ammunition before you would have to clean out the brass catch bag.

The bags are relatively common, and are of little use outside of the GPMG mount.

I'll post portions of the modification instruction.

Barry, PM sent