Well to start, you need to identify what kind of benchrest your talking about. I will asume you are talking about 600 and 1000 yard benchrest, as the powders you have stated, are inaporperate for what is used in "point blank" or 100-300 yard benchrest. Then again many shooters think that if you shoot from a bench that they are shooting benchrest, and this is not the case. In "point blank" benchrest the field of guns is dominated by the 6 PPC round, and most of the competition is using either N133 or 8208. There is a few that are using similar buring powders such as benchmark, 4198, T322, H322, BLC2, ETC. There are a few other that are shooting other cartridges such as the 30BR, or 22PPC, or other verients to this, but hardly anyone (Basicly no one competitive.) is shooting a 7mm. In point blank Benchrest the guns must weight under 10.5lbs for light gun, and under 13.5 for heavy gun. It is because of this that most shoot shorter barrels around 22 inchs long.
Now going on in 600 yard benchrest you will see a bigger array of caliber used, with the majority of competitive shooter using the 6 Dasher, or some other varient of the 6BR. Most common powders used with these cartridges is either varget, or Reloader 15. Some competators will shoot 6x47 Lapua, or 6x284, or there 6.5 counter parts and uses 4350 and 4831. Seeing someone shoot a 7mm is quite rare. Most 600 yard shooter use longer barrels at 28 to 30 inchs, as a light gun for them is anything that weighs under 17 lbs, and there is no weight on a heavy gun with many weiging in at over 75 lbs.
Now with all of that said, Reloader 17 and Hybrid 100V have similare burn rates as 4350, and 4831. Some 1000 yard benchrest shooters are using RE17 in there 6 or 6.5 shehane's with good results. I have found that RE17 is a bit dirty compaired to 4350, but it works well in small calibers such as the 20BR, and 20x47 lapua. I got amazing speed out of hybrid 100v in my 6x47Lapua, but there was no accuracy, so I stuck with old tried and true 4350. (Usualy the most common powder used in a 6x47L)
So hopefully this helps you out.