Cracked Brass

[CLL1975]

Help with new development .. used to be a competition shooter .. Bulls Eye .. PPC ... and Service Rifle ... my stars made rounds as good or better than factory .. inside the X at 50 yards .. of course the match 7.62 rounds were done single stage on a RCBS press .. still 9 ... 10 ring at 500 m but that didn't happen often in a match .. So I have started shooting my M1A's again .. I missed them .. Here's the thing .. I made up 300 match round 20 to 25 years ago, 43.3 grains of 4895 with LC match brass  .. kept in an ammo can in the cardboard's they came in.  Recently I shot some with my former sniper son .. shot at bulls eye targets at 100 yards .. 5 shot 1 inch groups .. great after 25 years ... Nope .. when I picked up the brass ... every case was split some missing brass at the neck .. I have checked LOTS of sites looking for the answer .. some reasonable heat, corrosion, bad brass, age ...  Anybody have an answer

[333OKH]

Some guy gave me a coffee can of old 22 Hornet brass, 80% of the brass split when I fired them, I think the old brass loses its lastisity after yrs, could aneal them, would be worth a try, George.

[lotech]

I suspect age is at least one factor, but there may be others. I've had this happen several times in the last forty years or so; always rifle brass, never handgun brass.

[Allaces]

Most likely, corrosive primers.