Really hate that you are going through this but hopefully you'll find a winner load. The 7RM is a great cartridge as a lot of people here have and can attest too with their "unicorn" loads. To all the new guys that chimed in, thanks and welcome to Long Range Hunting.
My first 7RM was in the 1st generation Sendero and man that rifle had what everyone needs. My load at that time (98-99?)was 150gn Ballistic Tips, 67gn of RL22 w/CCI BR2 primers, .010" off. I did not have a chronograph at that time so I have no idea what the velocity was, but it stacked bullets on top of each other! It was a true one-holer at 100yds and at 500yds, water filled, 20oz Diet Mt. Dew bottles were easily vaporized. That rifle/load gave me a "go-to" reputation in this area as the guy who could shoot and a lot of deer rifles came my way to sight in and work up loads for. Needless to say I got a lot of time in behind a lot of different rifles/scopes.
Like most good things in life, that rifle came to an end too. The factory barrel starting going South around 1300 rounds. It still shot .5" with a few .25" in there but started getting "unexplainable" (to me) flyers. It was shredding cleaning patches and took hours to get the copper out due to heat cracks.
I traded it for a Rem 700P with boot and I just knew this was the "tack-te-Kool" rifle from heaven and it was going to shoot those 168gn Berger VLD's into one hole. Well, it didn't, but I tried and I tried. After what seemed like an exhaustive, fruitless, humbling search I almost gave up on the rifle all together. I figured what the heck and decided to try those RL22 loads, nope didn't work. Another let down. Then I slipped a full load of IMR4350 behind those Ballistic Tips lit by Rem9.5M and BAM! There it was. According to my journal; .235" to .430" for several 5 shot groups. I shot it for a while, kilt a lot of critters with a 350-400lb black bear at 15 close steps. That Ballistic Tip killed that bear so fast. He absorbed all the energy that 7 Mag had and it turned him off like the proverbial light switch. I was amazed and relieved.
Fast forward to now. One of my son's own's that rifle now but it currently sets in my cabinet. A couple of months ago I decided to try the same rifle (that would not shoot the 168 Bergers) with some 169.5gn Wildcats I had pulled from 7RUM loads a fellow gave me, RL26 and BR2's. I was impressed with the results. It's not the fastest load I've had or heard of in a 7Mag (3062fps avg.), nor the most accurate (.6770") but it is consistent and it let me know I didn't know this rifle (or as much in general) as I thought I did.
I know I'm long winded and this doesn't help your actual load development but maybe it can encourage you somewhat. Good luck and keep us all informed as to how the "Green 7 Mile" is going.
johnnyk.