Impossible to answer without knowing at least which model.
Browning Automatic Rifle
Those are post cold war "fads", and are equipment for the 21st century military; see US Army small arms (21st century) websites. M147.62mm Rifle - - - - - You sight-in a M2 Browning with the M2 Browning itself.
Less than $100
bro
Both the BAR (Browning Automatic Rifle) and the Browning machineguns (series 1919) were made in caliber 30-06. HOWEVER, there were other calibers manufactured for special markets. Search Wikipedia for BAR, and look up some of the secondary calibers- they may be a surprise.
.22-250 Remington is a caliber and not a type of rifle. Several manufacturers have made rifles in this caliber. Without knowing the exact make, model, and condition of the rifle this question cannot be answered.
Over 3000 yds
ABOUT $700
Impossible to do with just the serial number.
Need a detailed description
The W818878 is not recognized. 70B30095 is a number for a Browning Lever action .22 rifle. Use the link to find value
Can't value with just the sn.
There is no such thing as a Browning semiautomatic M70 rifle. The Model 70 bolt-action rifle was produced by Winchester, while Browning produced a very different semiautomatic rifle called the BAR. Which is it?
There is no way of knowing without you providing the Model of Browning rifle that you own,its caliber,and a good description of your rifles overall condition.
Need a detailed description
100-1000 usd
100-1000 or more depending on specifics