If the price is good, buy it, buy a brick of solid point HV ammo and shoot s**t out of it, quite often the issues subside with break in. Doing a spring modification can help too. Before I even fired mine (I bought mine new) I cleaned it and polished any of the contact points of the action. I use VERY little lubrication for the action. Tweaking of the mags is sometimes necessary for some of these rifles, it's not difficult, if you buy the rifle you can pm me and I'll run you thru the steps. I run mine with a modified spring and it works great (allows me to shoot subsonics).