Which bullets did you try it with? The ELRs? XTP/crushribs, or the Shockwaves? If you had hangfires with them all, it could be something like your breechplug design or carboned up flame channel.I took the rifle and accoutrements out to the range today. I found some B209 powder and thought I would try it but I was getting crazy hangfires. I was using Winchester 209 primers. Are they not hot enough?
Like other folks have said... you shouldn't shoot Blackhorn in your Remington 700ML unless you have a 209 sealed breech set up (like I sell). You don't have to take my word for it... you can read the FAQ at Blackhorn209.com: FAQs « Blackhorn 209