I've been doing some testing.
I've had all sorts of problems since fitting both springs.
1st I noticed the pistol didnt shoot a BB every time.
2nd The slide stopped just short of fully forward, this is due to the BBU seal/O ring becoming faulty somehow.
3rd The slide won't lock open when the mag is empty.
So, I have a new CCT seal on the way and have removed all of the new springs replacing them with the stock.
Heroshark, you were right.