If it is clean and lubed properly, I would suspect it needs a new recoil spring and would look closely at the bottom of the bolt where it strips the next round in the mag. I would also ensure I was using quality ammo that typically has harder bullets.
The bolt rides against the bullet of the next round in the magazine as it chambers. Soft bullets, light recoil springs, a sharp edge at the bottom of the bolt face or a combination of these things cause varied types of malfunctions because of this. These things can also cause the bullet deformation you have in your photos. It can be frustrating because several types of jams happen and the cause may not have happened when the jammed round was chambered.
First the bolt may loose enough energy riding over the next round in the mag, it can't completely chamber the round. The worst case of this, the bolt stops halfway through chambering.
Another scenario, the bolt hangs up on the next round enough to jam it into the front of the magazine deforming the round. When that round is chambered, it may or may not completely chamber because the bullet is so messed up it doesn't fit. This is mostly a problem with cheap ammo that has very soft bullets and a rifle with a bolt face bottom edge that is too sharp. It is confusing because the damage is done when the previous round was chambered.
With this type of problem, a new recoil spring could mask a bolt face edge that is too sharp or an ammo with harder bullets could mask a weak recoil spring. Eliminate the variables you know may need fixed, then start working on the others. In the end, you should be able to get cheap soft bullet ammo to run reasonably reliable, other than a few miss fires.