In general,are these safe to purchase on? ...Definitely more to choose from as opposed to the shops here... I've heard of some excellent experiences,and a few horror stories...What should you watch out for,or is it just a crapshoot? Are some auctions more dependable than others?
As long as you have a local FFL that is willing to work with you and accept the transfers, you should be fine buying online. Yes there is some amount of risk but many sellers do allow a 3 day no fire examination period. I have nothing but positive experiences and generally, the guns are in even better than described condition. Make sure you and the seller maintain good communication so you know when the gun ships and when it gets to your FFL. My FFL holds the package and has me open it in his shop and sign off on the receipt.