Also no thoughts on the domestic issues either party wants to get through?
It's hard to believe the USA would want to pass gun control during a massive global war.
I believe it was Admiral Yokohama, Chief of the Imperial Japanese Navy who warned the hotheads in the rest of the military that in America there was "a gun behind every blade of grass".
Others knew of this, of course, and militarily, along with great oceans on both coasts, gave America a huge advantage from ever facing a invasion.
The gun control of the 1930's had most to do with alcohol prohibition and the gang warfare it caused.
The riots in the streets, the militarization of the police (there are also far,far more police at every level of the government today), use of illegal drugs, and crazy school shootings had not come yet until many more years. Also, believe it or not, some of the earliest gun laws in the US were Jim Crow laws passed to prevent black people from ever win owning guns.
With no prohibition and less racism in your time line, there would be a much less desire to pass laws to limit them.