Not because, but it does help things progress faster. In many cases several different firms or even individual inventors worked on the same problem and came up with several different solutions. They were able to do this because of governmental contracts asking for that solution and tended to get materials, ammunition etc.

Not only firearms or related stuff either. The groups who worked on things like breaking the enigma or the Manhattan project were large with many small but important breakthroughs from many different people.

The thing they all have in common is that they worked under immense pressure due to the war effort.