That is why the whole "Castle Doctrine" movement has been such a huge push in the national right-to-carry movement and by the NRA.
Most states (including Texas

Now we need a Federal Castle Doctrine.

By the way, to people pointing out the federal jury instructions do not state defense of third persons. Those jury instructions vary by circuit. Notice the different language in the Sixth Circuit (Tennessee, Kentucky, Ohio, and Michigan).
United States Sixth Circuit Court of Appeals, Pattern Jury Instructions
6.07 JUSTIFICATION
(1) One of the questions in this case is whether the defendant was justified in committing the crime. Here, unlike the other matters I have discussed with you, the defendant has the burden of proof.
(2) For you to return a verdict of not guilty because of a justification defense, the defendant must prove the following five factors by a preponderance of the evidence:
(A) First, that the defendant reasonably believed there was a present, imminent, and impending threat of death or serious bodily injury [to himself] [to another];
(B) Second, that the defendant had not recklessly or negligently placed himself [another] in a situation in which it was probable that he would be forced to choose the criminal conduct;
(C) Third, that the defendant had no reasonable, legal alternative to violating the law;
(D) Fourth, that the defendant reasonably believed his criminal conduct would avoid the threatened harm; and
(E) Fifth, that the defendant did not maintain the illegal conduct any longer than absolutely necessary.
(3) If the defendant proves by a preponderance of the evidence the five elements listed above, then you must find the defendant not guilty.
(4) Preponderance of the evidence is defined as “more likely than not.” In other words, the defendant must convince you that the five factors are more likely true than not true.