Recently bought a CETME, and fired it yesterday. It kicks the brass yards away which surpirised me, but upon inspection of the brass, all 20 rounds, were dented,from the neck down past the shoulder, the dents almost spiraled like rifleing, and were all the way around the brass from neck down. Is this normal? The brass is very dirty also. Never seen new fired brass this covered with what appears to be blowback from burnt powder.

Yes that is normal for the CETME and the H&K 91.

Those ridges you see are the result of the flutes in the foward part of the chamber.

Those flutes cause the hot gases produced at firing to enter the flutes and keep the case from sticking to the chamber.

That is why the cases are also "dirty".

The dent in the side of the case is caused durring ejection when the case strikes the rear of the ejection port.

There is a case buffer made by H&K for the 91, but I am not sure it will fit on the CETME.

It keeps the case from being dented as the case hits a rubber surface, and they do not eject out as far.

I have reloaded brass fired in an H&K 91 as many as 10 times without problems.

2 loads I use are a 150gr bullet over 42gr of IMR 3031, and a 165 or 168gr bullet over 39.5gr of IMR 3031.

What size groups does your CETME shoot at 100 yards?

Thanks for the info. I thought maybe I had put it back together wrong after initial cleaning.
I never put it on paper, but could hit gallon milk jugs consitently at a 100yds.