HOW DO I BUY A GOCK 30 GEN 4 ONLINE THINGS TO KNOW BEFORE YOU BUY

My next G30SF also experienced precision problems plus the WORST trigger pull of ANY Glock I've at any time owned, and I could NOT correct it making use of this set up it doesn't matter what I did and perfectly above 1,000 rounds of endeavoring to deal with it and “break in” the gun (which I have not needed to do with any Glock just before both