Dillon Case Feeder to Lee APP adapter for 300BLK

The genesis of this adapter was converting military surplus 5.56 brass to 300 blackout; I needed a faster means of swaging the crimped primer pockets.  Dillon only includes that capability in their commercial grade presses, so my choices were one of the aftermarket swaging setups for my XL750 (the use of which would void the warranty), continue using the laboriously slow one at a time swager, or find some other solution.

Enter the Lee App press.  Most of Lee's stuff is probably best characterized as being “medium quality, but functional”, and this is no exception.  It can be used for multiple functions, but the only one I am interested in is the primer pocket swaging capability.  In typical Lee fashion, they designed a mechanical feeding mechanism into it, which only sometimes malfunctions, but its real Achilles' heel is the need to feed cases into the included tubes one at a time.  They offer a case collating funnel thingy, but I already have an electric case feeder on my bench attached to the Dillon.  It does a pretty good job of automatically dropping cases into a tube right side up, and it really doesn't care what the other end of the tube is attached to.

So a couple of years ago, I parked an APP press on my bench next to the Dillon, and I machined an adapter on my lathe out of delrin, which will connect the ¾" tubing the Dillon feeder uses, to the appropriate sized adapter for 300blk that was included with the APP.  I bought a 3' length of ¾" OD, 1/16" wall polycarbonate tubing, used a heat gun to gently curve it to reach between the two presses, and trimmed the excess.  This setup continues to work great…  I realized at the time that 3D printing would be a much more efficient means of reproducing them, but I hadn't gotten involved in 3d printing at that time.

This model is a version of my original part, redesigned for 3D printing.  It's still a one trick pony in that it's only designed to feed 300blk brass.  It may work with 5.56 or other calibers, but I haven't tested anything other than 300blk and I have no interest in doing so.  There's already another guy who offers a more versatile adapter kit between the Dillon feeder and the APP press which works with many more calibers.  He seems to charge a reasonable price for it; I am not interested in trying to compete with him for commercial sales, so I am offering mine for download here.

I have only tested this using ABS, which has a slightly greater shrinkage than other filaments, so your mileage may vary.  Orient this with the wider end on the print bed, and print at a 0.2mm layer height with a decent number of perimeters and infill for strength, with supports turned off.  The model has a built in bridging support with a single layer height thickness, which will allow the internal corner to print correctly with no supports needed on the print bed.  This will need to be removed with an X-Acto or similar hobby knife prior to use.  This was drawn in inch dimensions, so unless you use the .3mf file, you will have to tell your slicer to convert.

I use this with a ¾" OD, 5/8" ID clear polycarbonate tubing.  A 3' length of this is currently $16.49 on Grainger.  You can also find it on Amazon but it's more expensive there.  I haven't tried it with a more flexible tubing, but it's possible that would work also.