GMB54-120 wrote:IMO the bare primer plug is a better investment. It works fine with BH209 or 777 and cleanup is a little easier.
Although I've never used the power stem I definately agree with the above. I recently purchased a Disc Extreme and immediately converted it to use the bare primer plug. It now shoots incredibly clean and ignites BH209 without fail. BH209 is the hardest powder to ignite so it should work with all the other powders as well. Plus you never need to buy and use the red plastic jackets again.
The bare 209 primer conversion kit is 41.99 which is a bit more than the power stem at 21.99. But I think the advantages are worth the extra $20 - UNLESS you are sold on shooting loose 777 powder and the power stem breach plug is signficantly superior to the bare primer breach plug for that purpose. I don't know the answer to that question.