split neck with unique in 30 carb

[Will]

When I use unique in my 30 carb loads I get split necks but not with 4227 or 2400 loaded to the same pressure. (ie 6gr unique or 12gr 2400 with Ly311410) Anyone know why?

Will

[jlchucker]

How many times have your cases been reloaded? Usually split necks come after cases have been stretched, trimmed, and reloaded a lot of times. 30 carbine cases are not really straight--they have a .020 taper. See the dimension drawing of that case in your loading manual. Do you know that you are actually loading to the same pressure with these different powders, or how many times, load for load, you have reloaded those cases? You've got some variables that may be possibilities, but realize that every time you reload one of those cases, you are reloading a tapered case and moving some brass. Eventually, it becomes work-hardened.

[elk hunter]

Will;

As jlchucker said they are probably work hardened, you might want to gently anneal them and give them another try.

[MtGun44]

As said, usually splits are related to how many times the brass has been worked (expanded
and resized) rather than the powder or pressure.

Bill

[Will]

Not a problem of work hardening. They only split with unique not 2400 or 4227. The unique load is (according to the manual) slightly lower pressure than the 2400.

Will

[Echo]

Well, Unique IS a faster powder than the other two - not that I can see any way that could cause neck splits...

[Larry Gibson]

Well, Unique IS a faster powder than the other two - not that I can see any way that could cause neck splits...

We need to remember that brass cases are both elastic and plastic. Unique "hammers" the case necks quicker, I believe this causes the splitting. It also is common if Unique or faster powders are used at top end (pressure wise) loads in other cartridges, particularly bottle necked cartridges. It is a real problem with reduced J bullet loades in many 30/31 cal rifles using unique and 123-125 gr sks/ak bullets in the 1800 -1900 fps range.

Larry Gibson

[Will]

I think Larry has the answer.

[mj2evans]

What is the headstamp of the brass? If it is Amerc (from Florida) then the brass is simply a *** (called them about splits and FTF on NEW ammo and they simply don't care).

[jimb16]

I agree. I won't fire Amerc in any gun I value and if I find their brass at the range, it gets crushed and thrown in the scrap bin.