Saudade, I'd have to guess that you're using good ammo, or you're using a good grip. I think the red spring just makes the gun a little more prone to 'not go all the way into battery' when using a 'less' than optimal grip.Interesting. My 5"'s have the red spring. I haven't had any failures going into battery but then I've only shot FMJs.
Perhaps Walther will send me silver replacements? I'll call them Monday.
Hello Wick. Yes there is a difference. In the beginning Walther thought the 5" need a little lighter/weaker spring, hence the red spring. After a couple of years (could have been a little less) they realized the 5" actually ran better with the 'silver' spring. Now, the silver spring is standard issue with the poly 5".
So, you're OK.