The breech plug for your master hunter should be the same as the plug for the disc extreme. If you want the non full plastic jacket conversion I think midsouth has them pretty reasonably priced. Shipping charges seem high but, when you figure it costs about 60 cents a mile to drive, it is generally cheaper to have something delivered. As far as the bh 209, some people report good successwith the standard breech plug while others like the conversion better. I bought a jug of it but haven't had a chance to try it yet.Good luck, Art