I recently had a 7 LRM built by s local Smith here in Tucson, az. I have read everything I could get my mouse on, all signs obviously pointing to H1000. Luckily, I have about 5# on hand. I have only been able to fire 5 rounds though my gun. So far, it appears 70-71 grains will be my max, (175 LRAB). Azshooter and I have been in constant communication about different powders to try.. he was even nice enough to sell me some. So, other then H1000 what powder choices do I have? For this rifle, I have on hand h1000, US 869, Retumbo (scored 2# yesterday), RL 33, 25 & 22.