****First and Foremost, I shoot and prefer Retumbo but was asked to try this. Im not pushing this just FYI. I get sick and tired of buying 10-20lbs of retumbo at a time because its so hard to find. Its like buying toilet paper now days*****

Loads were started at 135 and ended at 145 -- 350SMK- 32" barrel --550ft density alt -- 56*F --lab radar,--.020 off lands

velocity started with 3020 with 135gn (I think this is a very safe starting point for anyone)
velocity ended with 3190 with 145gn (jump in velocity noticed over 140gn)

No signs of pressure at any load
In an attempt to get some powder temp deviation 5rds were left on my dash with full defrost for 20 minutes and they were hot to the touch. I picked up about 20fps out of those rounds. I didn't notice much temp instability but this will change lot to lot as with all powders

my preferred plinker is 135gn of retumbo under a 350smk and that nets about 3100

They only reason I did this was the lack of info on RL33 for the cheytac. I gained some speed but didn't push the loads hard. I think I could have gone another 8gn or more before I started flattening primers etc. I was shooting med range at 1000yd steel, groups appeared to be normal for the rifle. My particular rifle has never exhibited "nodes" it shoots 1/2 Moa on paper at 200 and has never been finicky but I really don't shoot paper often at all.

What's the drop and windage (10 mph, 90 degrees) at 1000 for that beast?  My "plinking" load for my Creedmoor is less than a third of your powder charge.

sorry never saw or got a notification of response

at a 1000 probably 17ish moa dial on a 200 zero and upwind edge of a 2moa plate, sometimes I run a 500 zero as well. I go off my kestrel and shot log most of time. The cheytac is a good round, Im running a stiller action and March scopes. Barrel change at around 1000rds. (once a year for me) usually I wait for the late July or the holidays to take the rifle out of service.

Sorry I don't really know anything about a creedmores. My daughter shoots a 243ai that's probably similar. However she's playing with a 30-338LM now and not sure how that's working out.