Ok, not really your fault. I worked too darn hard this year and got myself a present. I deserve it. I just picked up a brand spanking new CZ550 in .375H&H (Standard Safari) Holding 5 down in that magazine makes me quite happy. Just something about that number that makes me feel better. With it, I grabbed a box of winchester ammo, just to put bullets through the barrel. This weekend. I then started to scramble to find bullets, powder, dies, recipes etc. ZERO supplies in town. I have ordered from across the country. The courier is bring 50 Brass, 2 pounds of powder and 2 boxes of Barnes 250 grain TTSX are on the way. A full die set is on the plane coming back on Friday from Ontario. The research started: On AH: Phil was working this one up a while ago and did some extrapolating on it. I emailed Ty at Barnes directly and asked what the reloading recipe was for these bullets. This is what I got back: "We are simply suggesting that you split the difference between the 235gr and 270gr TSX data for the 250gr TTSX bullets. See attached" Seems Phil was right to do what he was up to. Some other findings: Hodgdon doesn't even recommend over 69gr of H4895 with a 250gr bullet. Another one: Barnes 250gn TTSX / Reloader 15 / Fed215 / Nosler Brass / NO crimp 73.5gn - avg 2695fps 74.5gn - avg 2745fps 75.5gn - avg 2785fps 76.5gn - avg 2801fps 77gn - avg 2833fps And then some lunatic from Namibia (DOC!) suggested this recipe: "I found that my 550 .375 likes a jump-start..! I get sub MOA at 100 and 200 with Norma brass, 250gr Sierra GK's (my favorite bullet) and 65 gr of Somchem S 335. Velocity around 2560 fps." Apparently IMR 4320 is an equivalent to the Somchem. I'll be trying the IMR 4895 as suggested by Barnes and extrapolating between the 235 at 270 grain bullets and come up with something that works. I can only hope the CZ likes the TTSX as much as my other rifles. I'll see how it goes. thanks for everyone contributing and putting the information out there to be found. Anyone used GS CUSTOM Solids. 300 Grain?? Getting solids up here is impossible.