RCBS Uniflow Powder Measure

Just wondering if anyone has run into this before.  I left Bullseye in the hopper of my RCBS Uniflow for about 3 weeks and it ATE the into the plastic tube.  Tried cleaning it but the plastic is soft and sticky.  I just started using BE, never cared for it.  Is this something I need to worry about happening with BE?  I've left other powders in it for months at a time without issue

Call RCBS and they will send you a new hopper.  It's not just bullseye that will do that but many other powders too.

dannyd93140 wrote:Call RCBS and they will send you a new hopper.  It's not just bullseye that will do that but many other powders too.

It's a Uniflow 1 non-removable Hopper.  I've had it going on 30yrs lol

Still Give RCBS a call and see if there is something they can do. They are a great company to deal with.

If RCBS can’t help, try these guys… 

https://dramworx.com/

They make a powder hopper from aluminum and Pyrex, chemically inert.

Being too cheap for the pyrex solution I put a sheet of paper around the inside of hopper of my uniflow.
I do have to put some effort into watching my powder level now.

Kallysan wrote:Just wondering if anyone has run into this before.  I left Bullseye in the hopper of my RCBS Uniflow for about 3 weeks and it ATE the into the plastic tube...

Common problem with leaving powder in a hopper, the cause is simple.  The chemicals in the powder are attacking the material of the hopper, with the results you have observed.  Solutions:

• Change the hopper material.  As others have mentioned, a Pyrex hopper tube is available, but is not inexpensive, OR;
  
• Empty the powder hopper each time you are finished reloading.  A cheaper solution than buying a new hopper (though it sounds like you need one at this point), just remember to do it at the end of a reloading session.
  

Best of luck in obtaining a new hopper, RCBS is pretty good at replacing parts.  Hope this info helps in the future.

Double base powders use 2 energetic ingredients, nitrocellulose and nitroglycerin.  The plastic used in the hopper is not resistant to nitroglycerin (NG).  Single base powders do not use NG so they will not cause the hopper to break down.  RCBS will replace the hopper but you might have to send the powder measure back to them for this to be done.  Once replaced, do not leave the powder in your hopper longer than necessary.

My Dillon powder measure hopper must be a different plastic.  I've left WST in it for months, and it doesn't seem to deteriorate.  Please let me know if I shouldn't do that, I don't want to lead anyone else astray.

I am not sure, but WST may be a single base powder.  The percentage of NG will also affect the speed of the reaction.  Some powders have a higher percentage than others.

rburk wrote:My Dillon powder measure hopper must be a different plastic.  I've left WST in it for months, and it doesn't seem to deteriorate.  Please let me know if I shouldn't do that, I don't want to lead anyone else astray.

Don't know about the Hopper, but it's definitely a fire hazard.  I have emptied mine after every reloading session even when I Dillion's before switching to Hornady LNL's.  

I have kept Bullseye in my Star hopper literally for years with no issues.  Some may argue that this is not a good idea, but...