Problem with R-15 in 550B.

[ZiaHunter]

With Varget no where to be found I thought I would try R-15 in my 550B for 308 loads. With Varget, the 550B threw consistent loads +-.1 grains. With R-15 it is all over the place with several grain variations. The powder throw has been polished with a UniiqueTek micrometer adjuster and powder baffle installed. I disassembled the powder throw and checked everything including making sure the cases are fully activating the throw. Same result. As I lower the ram, grains of powder trickle down on the press even when the ram is held in the up position for several seconds. Has anyone run into this problem with R-15 and any suggestions on how to fix. I have a bunch of R-15 and would like to use it until Varget is once again available.

 

[ZiaHunter]

Re: Problem with R-15 in 550B.

Steve:

Thanks for the reply and will give it a try. There is no mechanical reason why the dispenser should not handle R-15. Going ti check my setup again today.

 

[ZiaHunter]

Re: Problem with R-15 in 550B.

Ok I think I have it worked out. I have a Whidden tool head holding the dies and tightened the screws on the toolhead with cases in all stations and loosed the two hex bolts holding the powder measure clamp to let the powder measure float. Checked the throw weight with cases in all stations and was +-.2 grains then loaded 50 rounds. The jarring action of sizing the cases as well as keeping the ram in the up position for a few seconds allowed all of the powder to flow into the case and eliminated potential bridging. There was no spilling of powder on the press.

One thing I have noticed is the difference in runout between various makes of brass. Federal brass due to its thicker neck wall shows greater runout than Hornady match and the amount of force required to draw the expander through the neck is significant. The increased runout is due to the expander pulling on the neck in the down stroke. I ran some Federal brass through the die without the expander and indicated minimal runout. With the expander the runout increased by about .005 on the neck.

BTW all cases were annealed prior to sizing.