One of the most common issues that cross my work bench is: On magazine fed semi-automatics like Auto pistols, rifles and AR’s, “The cartridge is stubbing just outside the chamber of the barrel”. Most are due to the magazine being poor quality. The guiding feed-lips on the magazine flex open and do not properly guide the cartridge onto the bolt face and into the chamber. You can easily examine the magazine feed-lips by squeezing the magazine between your thumb and finger at the feed-lips to see if they flex. A good magazine will be very stiff and not flex.
Save yourself a trip to the gunsmith and buy a good quality magazine and see if it cures the issue. If not, at least you have another good magazine.
Another possibility is that the extractor is not functioning properly, this is quite common even in new mass-produced firearms. The lonely extractor has multiple duties to perform on some firearms. It not only extracts but also can hold the cartridge against the bolt face which helps to align the nose of the bullet into the chamber. It also holds the extracted case against the bolt face so the injector can firmly pivot the case off the extractor and out the injection port.
If the new magazine does solve the issue, call 619 729-5436 and make an appointment to bring your firearm to me for a free evaluation and repair quote.
Gunsmith Greg