This site will answer your question: http://www.browning.com/customerservice/qna/detail.asp?ID=107
It can be done.
You can tell if you have a Browning Gold Medallion Boss Rifle by looking at the stamp on the barrel. It lists the model of the rifle as well as its serial number.
On some models, yes
Try midwestgunworks.com
BOSS stands for "Ballistic Optimizing Shooting System". With the BOSS system installed properly, the intent is that once a rifle is sighted in with a particular ammuntion, the BOSS increases accuracy by reducing barrel vibration. Each caliber, bullet weight, and Ammunition Manufacturer, has a setting for your model of rifle. The setting is what Browning calls "The Sweet Spot". For instance, you may have a .30-06 and you shoot Federal 165 grain bullets. The BOSS guide will tell you which setting on your BOSS (sweet spot) will optimize the shooting accuracy of your rifle. Click on the link to the Browning Web page that shows the settings for all calibers rifle models.
The browning is typically your common sniper rifle with a scope added , but you could use a M240 , and put a scope on it , LIKE A BOSS
You will have to shoot the load at different settings to find out which one works best with your particular rifle and ammo.
Boss is a muzzle brake vibration controlling device attached to the end of a rifle. The BOSS system is proprietary to Browning Firearms Company. The purpose is twofold: 1./ Help to reduce recoil with the muzzle brake. 2./ Using a dialing system ( incremental numbers on the BOSS) you can set the ammount of vibration to the barrel for each ammunition load you use. This when used properly is suposed to greatly tighten the shot group on a target.
I know that Browning made a Greywolf A-bolt rifle in 30-06 because I have one. I don't know if they made any in .270 cal. The Greywolf was only manufactured in 1994 with very limited production. I've heard that there were only 380 made. They are stainless steel with a wooden stock and came with the Browning BOSS attachment.
Please contact Browning at the related link
A call to Browning for a manual or a trip to a gunsmith is in order.