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

My next G30SF also had precision difficulties along with the WORST trigger pull of ANY Glock I have at any time owned, and I could NOT right it working with this setup regardless of what I did and perfectly in excess of one,000 rounds of trying to take care of it and “split in” the gun (which I have NEVER had to do with any Glock before either)