Thanks for responce.st_albert said:First thing I'd look at is the extractor. Increase the tension. Does this happen at any particular place in a magazine load? Like, for example, on the last round? or is it anywhere? What do the ejected cases look like?
Edited to add: OK, I wasn't reading closely. Every third or 4th round. Still, I'd look first at the extractor tension.
Very true. In fact, there's much more to correctly tuning an extractor than bending it to add tension. I encourage the OP to read the extractor fitting sticky above.Replacing the extractor doesn't necessarily mean it's tuned correctly.