It is a great system. Use the vented end with plugs and muffs to work up loads. Use the unvented one for hunting. It does not make you a one load shooter unless you can't write down the settings for various loads and reset the BOSS if you change loads.
A 7 mag is not really a rifle you'll be changing loads in anyway. Put a premium 140 gr bullet in it, work up a load and you're set for anything from Antelope to to a typical Grizzly (600 pounds). Load development is as obsolete as a Model T. A 140 TSX in front of a lot of 4831SSC ignited by a magnum primer will shoot 1" 3 shot groups all day and kill anything you point it at.
The BOSS is a prime example of the engineers being ahead of the shooters. We have an early 30-06 BOSS BAR in the family that will shoot 3 of anything from 110 gr chuck busters to 220 gr Hornadys into 1" or less. "Load development" consisted of finding the powder that gave the highest velocity through or Chrony and then tuning the BOSS for accuracy.
I had two late New Haven Winchester Model 70s in 270 WCF. They were twins but one has a BOSS. The "naked one" was a one load gun. 130 gr Accubond and 59.5 4831. The BOSS one will shoot anything. Guess which one went down the road ?
Snap it up as they stopped making them.
My Winchester Super Grade .270 (without the BOSS) will shot any grain (130,140,150 and 160 Np's) bullet I want into an 1" +/-. Bought it in late 1991 early 1992.
