Parsifal,
I can't agree with you I'm afraid. The German smallarms industry was infact well ahead of anyone elses, Germany's clear lead in aerodynamics ballistics combined with their prowess in engineering enabling them to produce more advanced and effective weapons ammunition than anyone else.
For example Germany was the first country to design, build and deploy a truly effective dual purpose machine gun, the MG-34. The MG-34 was a breakthrough in machine gun design, being very light, accurate, fast firing and beltfed it was like no other MG in history and no'one had anything like it. To no surprise the Allies really came to fear this weapon and even more so its improved offspring, the MG42, arguably the best machine gun in history.
In North Africa where the were many large open stretches of land the British came to refer to the MG34 42 as automatic cannons, as they were often being engaged at ranged past 3000m, and effectively so, much to the surprise of the poor British troops caught in the fire.
The Allies failed to design any such effective machine gun during the war.
As for SMGs, well the Germans were the first to put these to use during WW1 and the Wehrmacht were very well equipped with SMGs at the breakout of WW2, infact it was equipped with more SMGs than any other army of any other nation.
Moving on to rifles,
Well the StG.44 was the best infantry rifle/smallarm of the entire war, and the G-43 was a very good semi auto rifle which was comparable to the Garand.
On the StG.44:
View: https://www.youtube.com/watch?v=SccU2BppZeg
View: https://www.youtube.com/watch?v=VOFSdtUUQj0
Being fired (one alongside AK-47):
View: https://www.youtube.com/watch?v=W_XIN7VMUzc
View: https://www.youtube.com/watch?v=rRYm11j3wwA
Germany also fielded the most accurate sniper-rifle of the war, the bolt action Karabiner 98K. Being the prime smallarm for most German soldiers up until very late in the war, it lacked the firepower of the semi automatic rifle and was very much due to be replaced as the std. infantry rifle by either the G43 or StG.44, it however came completely into its own right once deployed as a dedicated sniper rifle. Equipped with the best optics in the world ranging from 1.5, 4, 6 to 8x scopes from Zeiss or Hensoldt Dural-Dialytan, and firing heavy boattailed projectiles, it was every sharpshooter's dream rifle. For long range sniping nothing came close.
As for ammunition;
Germany was the first nation to deploy boattailed projectiles as-well, the most common types being the heavy, low drag and very high BC 198gr Patr. sS [Schwere SpitzGeschoss] FMJ-BT projectile and the 178gr Patr. SmE [SpitzGeschoss mit Eisenkern] AP FMJ-BT projectile. These two projectiles feature very high ballistic coefficients, the Patr. sS having one around .580 to .590, while Patr. SmE has one around .510 to .520, MUCH higher than any Allied rifle projectile of WW2 and infact also higher than todays 7.62mm M118 Matchking sniper projectiles.
The 30-06 cartridge can be criticized today, but in 1940 it had few equals.
It did have one superior though, the 7.92x57mm Mauser.
The .45 in pistol ammunition was a tad big, but it at least gave the US ttroops the confidence to believe it had a killer knockout punch.
The key word is "believe" as the 9x19mm Parabellum is more accurate and has a high kinetic energy. Nonetheless the effect is the same, they're both sidearms and so they aren't knock overs.