If it were me I'd load up nine of those at each weight and go out on as calm a day as possible and set up a 300yds target.
Let the rifle cool down completely between each three round group.
take the average from each weight/charge and see which gives you the best accuracy.
You can tweak up and down with whichever gives you the best results until you find that sweet spot between accuracy and speed.
Once you've done that as long as you are seeing zero pressure signs, you can adjust your seating depth outward a couple of thousandths at a time and see if that tightens it up even further.
Unless you plan on shooting prairie dogs beyond six hundred yards anything under 1 MOA is acceptable especially in an SPS.
Question, have you done a complete float and bedding job? Does it have an aluminum bedding block or factory pillars installed?
If you haven't done the floating and bedding I would not mess with anything else until that is done because your results over the long term are likely to be very inconsistent particularly with changes in temperature and humidity.
Give the 150gr Sirocco II a try.Hi Bill, thanks. I was thinking the 150-154 weight bullet or maybe a little lighter would be best too. It did shoot the 150 powerpoints as a factory load bad today. If I had a higher power scope on it, I would have been able to dial the crosshairs in more. I'm going to put my vx-3 4.5x14 on it tonight. I had a custom pic rail put on it, but it's interesting to hear you say the rings stress under recoil. Would this have any effect? I'll check the rings, but tomorrow I'll have either nightforce rings or TPS rings. Today was just a 1" tube, old bushnell 3x9x40. Not what will b staying on it. I may put my nightforce on it tomorrow or the vx-3 will do at 100-200 no problem. I love Ruger No. 1's so I hope to get this down to 3/4" soon. Trigger pull and foreend I'll probably play with last.
My mistake. I thought they came with a 24".Wildrose,
The 7mm stw stainless guns have a 26" barrel on them, or at least mine does from the factory. I bought mine new in 2001.
I have a Bushnell 4200 2.5-10x on mine. I have thought of a new scope for this, but then I would do new rings too. The rear ring is really close to the center of the scope to get the proper eye relief for me. Leopuld makes some extension rings for Rugers, and someone makes a base for mounting Weaver style rings.
Bill