Horndy nickel 223 case seperation

[jeeptim]

Hey fellas. went to the range yesterday shot a converted Saiga 223 21'' barell and a valmet port buffer.
The reloads were 55gr fmjs using BL-C-2 (light load) 23.4gr. 1st reload so second firing, had one case seperate about mid way center of the case, today cleaned and inspected the brass and on 12 out of 50 a line going around the same place, did the bent paper clip on all and a deep groove on only the 12 with the line all others seemed ok. even cut a few open and good to go.
Now I bought this ammo new just so I could reload it so I know for a fact 2nd firing. I have loaded TONS of 223 but not much nickel, is this common?
I have loaded other headstamps 4 and 5 times no trouble, I thought Hornady
was a quality product. All cases were trimmed and a Lee factory crimp die was used, all i can think of is over crimping but I just don't buy that.
I have like all of us had my case head seperation but this was really out of the norm, ol'most like a bad lot of brass but if that were the case i think the other 38 cases would show some of the same issue.

 

[788Ham]

What is meant by "a light load"? How many grains of powder were loaded for these rounds? Some powder is meant to be loaded as instructed by the reloading book, anything below these numbers can cause trouble! Also, punctuation is sure nice in these questions posed, sure makes for easier reading and understanding!

 

[Walkalong]

Head space issue, or over sizing/pushing the shoulder back too far. Brass should not do that on the second firing, or the third, and nickle or not has nothing to do with it.

 

[243winxb]

Russian Saiga 223-Head Space

A Russian gun control feature that marks the brass so the authorities can tell if ammo fired during a crime came from a civilian weapon. The central portion of the bolt face around the firing pin hole is raised. This imprints a ring on the case head around the primer when fired. The step measures .008" Removing it can cause excessive headspace. Reload the brass as is.