Curious case split

[inthebeech]

I was shooting some gallery loads through my K-38 and had a case develop a split about a quarter inch long and in the middle of the cases length.  It was a very light load (1.0 gr) of bullseye which might have been the cause in some way.  No high pressure signs at the primer or by measuring case diameter or extraction, or by felt recoil.  The case and gun seemed normal in every other way.  Brass is not more than a year old and was fired I believe two or three times previous with full length resizing each time.
I was experimenting so I only had the one round with that charge.  I fired one round previous with 1.5 grains with no issue and my proven load has always been 2.5 grains.  My point is that I have no more of these ultralight loads and wouldn't fire them if I did.  This was just early stages of gallery load development so I had only one round at each powder level to just make sure the 148 gr wadcutters exited the barrel.

Any ideas?

[us920669]

My hunch - and that's all it is - would be a bad case.  It may have failed the previous time.  I've caught small splits after sizing that didn't seem to have leaked any gas - no stain, just a small mark on both sides.  Maybe the brass failed but didn't actually rupture.  Then your ultra-low pressure load opened it up.  With low pressure the case is not mashed against the cylinder wall so the split would look real bad.

Back when I had more curiosity than sense I loaded four tenths gr Bullseye in 44 Mag to see if I could see the bullet.  I could, just a very quick silver streak like a tracer.  People whose opinion I respect have told me I was out of my mind, but they all seemed very consistent - all looked the same and all hit the target.  That was before I had a cronograph but I bet they were at least a couple of hundred fps, probably would have been lethal with good shot placement.     

[Land_Owner]

If it continues, there might be a problem to worry about.  One split case isn't a sincere worry.  It happens to all of us.

[noylj]

I find that .38 Special brass is, for some reason, the most likely case to split as you mention. With used brass, I get 2-3 out of 200 rounds splitting every time I go out. .357 Mag is second. After that, I have not had any cartridge split more than maybe 1 in a 1000.
Also, nickel cases split even more often.