Slight problem with RCBS Piggyback

[pt4u2nv]

Been using the RCBS Piggyback on my Rockchucker for years without any issues but recently have been having problems with the return spring on the powder measure hanging up and not pulling the actuator rod back into position. I have disassembled the powder measure and cleaned it, made sure there were no burrs on the steel powder drop cylinder and can't seem to stop it from hanging up. My next step was going to be going to the hw store and try to find a stronger spring to return the cylinder to the correct position. It has been progressively getting worse and does it almost every pull of the handle now.....very frustrating. Anybody have any experience with this problem that can help ? I have also tried rotating the powder drop tube at every possible position to try to get a straight as possible pull on the spring to no avail.

[Catshooter]

Mmm. I too have been running a Piggyback for some years. Never had that as an issue.

I have found from time to time that burrs & rough edges can cause major hangups. I'd look for some.

Keep us posted will ya? Could happen to me!


Cat

[curiousgeorge]

I also have a Piggyback, actually the 2nd version, and have not had that problem, but I do have a thought on your problem.

I have 4 of the Uniflow powder measures, 2 from the early 80's and 2 that are from the early 70's. The earlier ones have what looks like a chromed cylinder and the later ones have blued cylinders. I have never had a problem with the older ones wanting to get "sticky" on me, but both of the blued cylinder models will regularly (maybe every 8-10 weeks) start binding and getting difficult to operate. My solution to the problem has been to empty the measure and put exactly one drop of any lubricant on each side of the measure drum and to rotate it several times to spread it around the cylinder. In checking the drum, it only migrates approximately 1/8" over from the edge and never gets anywhere near the powder. The measure immediately opperates freely and stays that way for quite a while.

I opted to put one of the older measures on my Piggyback II and have had no problems and it has been in use with Unique powder for years. On a side note, it sure does look funny sitting on top of a LYMAN Orange Crusher!

May not be solve your problem, but sounded familiar to my experiences with the 2 newer measures.

Steve

[CATTLEMAN]

Which type of piggyback and uni flow actuator are you using? I use the now discontinued ammomaster progressive which is very similar to the older piggyback units. I also have to lightly lube the measure occasionally. I also upgraded from the old mechanical rod actuator to the newer case activated linkage and it was a vast improvement.

As a side note I have used case activated linkages from both Hornady and rcbs on the press and they are basically interchangeable. I recommend buying which ever is cheapest unless yours is already case activated.

[pt4u2nv]

Mine is not case activated but sounds like a good improvement. I actually have already used powdered graphite on the measure cylinder and did not seem to help. I have torn the measure down and checked for burrs and rough spots and actually polished the cylinder and frame of the cylinder holder a little . It just seems as though the spring has gotten weak. Think I will call RCBS and see what they say.

[1bluehorse]

Are you using the long spring that goes all the way around the measure above the micrometer or the short spring that attaches to the arm?? I have a couple of both that I'm not using since I changed over to the case activated linkage, (much better). If you can use them give me a shout, I'll send them to you..

just thinking, something else you might check is that the measure isn't sitting to low on the press that when the "rod" actuates the arm up it isn't raising to high and maybe jamming at the top of the measure's slot..

[cwskirmisher]

I use the PBII, and have had a similar problem over time. I just ended up recently getting fed up, and bought the case-activated linkage upgrade. A superior and vast improvement, and sorry I didn't do it years ago. Works extremely well, and no more accidental powder throw onto the shell plate to clean up!