My LNL AP bullet feeder die (fed with bullet tubes) doesn't like several different brands of inexpensive coated lead.
I have plenty of 'medium' to 'very respectable' quality bullets that flow just fine, but coated lead 'plinkers' were often fussy, at best.
After thinking about it for way too long, I finally broke down and bought a MBF Bullet Feeder Die. (A bit spendy for 'what it is')
As I already had the Hornady tubes and don't mind using them, all I needed was an adapter.
Materials include a 1/2" CPVC coupler and a very short piece of 1/2 CPVC pipe inside one end. (Rattle-can finish optional)
I used a Dremel to enlarge the inside of one end of the coupler approx. 30 thou. (Die side)
To hold my Hornady 9mm / 38 / 357 tube (as shown), stick the 1/2" CPVC pipe into the other end of coupler, cut flush.
You'll also need to enlarge the inside of the CVPC pipe a bit to accept the tube.
*** (I found this to be the most time-consuming step, due in part to using my somewhat limited selection of Dremel bits suitable for the task)
*** UPDATE: If you have a 31/64th drill, use it instead of the Dremel. I picked up a cheap set of bits at Harbor Freight yesterday. Popped the small section of CPVC pipe out of the coupler and replaced it with a new piece. Took a couple passes with the 31/64th to achieve the fit I wanted, but all around faster and 'straighter' than a Dremel. (Again, 9/38/357 Hornady bullet tube)
I completed 150 rounds of ammo recently and the MBF die dropped every single bullet without a hitch.
The only 'issue' (?) I ran into was repatterning my habits on how to remove the bullet tube from the die. If I don't drop every last bullet out of the die itself, and attempt to remove an empty tube without holding the top sleeve of the die down, the tube will pull the top sleeve up and instantly dump all the remaining bullets..
Other Info:
MBF Pistol Feeder Dies appear to involve 1 die for 9/38/357 and another larger(?) die for 40-45. Everything you see above pertains to the 9/38/357 die, and I do not have the 40-45 die.
If the top outer diameter of both dies are the same, (or close) I have reason to believe that you can most likely use the same CPVC parts for 40/45 as well, and not even need the Hornady bullet tubes as rumor has it just a simple length of 1/2 CPVC works as well. (In my area, Homer Depot stocks both 10 and 2 ft sections of CVPC.)
The fundamentals of my adapter were obtained via 1 video on UTube. The author of that video was creating an adapter to connect a MBF bullet feeder die to his Hornady Bullet Feeder. While it appeared to be a bit more involved and utilized a couple more 'Homer Depot' components, it didn't appear to be difficult.