I found this post on another foum. I hope it provides a valuable clue. ....
My favorite load was (notice past tense) 52.0 gr Norma N205 with a 85 gr Nosler Zipedo. Neither one is made anymore, but Nosler is getting back into the solid base bullets and Reloder 22 is a Norma powder that is almost identical to Norma MRP (that took N205's place). The "can" even says, "Made in Sweden" on it, plus I have a copy of a letter from Hercules stating that origin for the Reloder series.
That was a long time ago, about when you got your 700, when I was looking for speed. "Speed kills!" or so I thought at the time. Since then, I have finally figured out speed only kills if it hits what you are aiming at. I load things slower now than I used to, up to a certain point.
#1 son is shooting 27.5 gr Blue Dot in a 7mm Mag with 139 gr Hornady's at about 2300 fps and he killed a doe with that load this year. However, he wanted some of my dad's loads to try, so I loaded 68.0 gr IMR IMR 4350 with those same 139 gr Hornady's. Today that load is a gross overload, but it still shoots just like it has since the 1960's. Three shots touching at 100 yards and no signs of excessive pressure in his stainless 700.
The reported loads today don't even come close to what was used back then. So, all we can do now is use the manuals as a starting point and keep experimenting until we arrive at the desired results. The RL 22 loads in the manuals give a starting point for the 6mm, but it's going to take some time to actually wring a good load out.
A lot of people are scared of the old Speer #7 and Speer #8 loads, but I have brass headstamped .244 Rem from the days when anything other than 100 gr was .244 Rem. I don't know that I have ever had to throw away a .244/6mm case, which indicates safe pressures have never been exceded, regardless of what the manuals say today.
Sorry for the rant. It's just my opinions, so take it for what it's worth.