Stuart wrote:

Your average burglar entering your home is extremely unlikely to be
carrying a gun and you still have the right to use reasonable force to
defend yourself and your property.

Not in the UK, you don't.

"Anthony Edward Martin (born 1944) is a farmer from Norfolk, England, who in
1999 killed one burglar, and wounded another, who had invaded his home. He
was subsequently convicted of murder. As a result, he became a cause célèbre
for some, and polarised opinions in the UK"

Nor in some states (Iowa, New Hampshire, New Mexico, Virginia, D.C.)

In other states, you may use reasonable force only if it impossible to
retreat.