308 enfield reduced load problems

[Sharps-Nut]

My brother was shooting a enfield design india made 308 with reduced loads and lead.  The load was out of the lyman book and was using sr4756 imr and a cast lead bullet, something went way wrong and he experience case head failure blowing the extracture off the rifle.  No one was hurt  and the gun can be repaired but what went wrong?   My brother is a extremly careful handloader and the report and recoil seemed normal so we feel a double charge is out of the question.  But again what happened?  I know some reduced loads can have deonation, spelling, problems causing spikes in pressures.  Tell me what you think.  Thanks for any insight, mods feel free to move to the category you feel this belong in.  SN

[Castaway]

Sounds to me like the brass was ready to go.  How many times had it been reloaded and did you check to see if it had thinned near the head by rubbing a paper clip inside?  The first question is really moot.  Some of my rifles I'll shoot 7 reloads with the brass, in my SMLE, only two, mabe three.  It depends on the rifle.

[Sharps-Nut]

This is data I do not have.  You say in your smle, I am not familiar with the term.  Why does this rifle, ? get so few reloads.  I like your thoughts, tell you the truth my brother and I were leaning towrds brass failure.  I know some reduced loads can detonate or experience pressure spikes.  It alarmed me due to my tendancy to load reduced loads using unique and cast lead in the my 30-30. Thanks for the help and any more light you or other can shed.  SN

[Castaway]

SMLE, Short Magazine, Lee Enfield, the brother to your Ishpore.  The chamber tended to cut a little looser than what you would find on American rifles.  Didn't hurt anything when firing issue ammo, but if you reload for it, the brass flows forward from the head area more than on most rifles.  The consequence is that each time it's reloaded, it flows (brass doesn't stretch) again to fill the chamber, thus thinning the brass to the point it will cause a head separation.  Don't know if the Ishpore was cut as generously as the SMLE.  Someone else needs to chime in here.

[Sharps-Nut]

Thank you very much for the education.  This seems like a possible case to his failure.  I know he does not have many cases and has shot the rifle several times.  If the rifle has this issue that would bring on the case head seperation.    I will relay the information to him.  Tbaks again SN

[Steve P]

Your Ishapore .308 will be "field" gage or even bigger.  If you are full length sizing brass for your reloads with dies at SAAMI spec, the ammo is probably floating all over in the chamber.  If the case head was not flush against the bolt face, you could get expansion that could damage the extractor. 

Seat the cast bullets out so they engage the rifling.  Use a load of Unique or the 4756 to fireform your brass.  Then only size the case down the length of the neck.  Bumping the shoulder back too much will give you excessive head space and will lead to case head separation or more broken extractors.

You would not normally expect to get detonation from 4756, but I cannot rule it out nor say it didn't happen.

Stay safe and keep shooting.

Steve

[Sharps-Nut]

Thank you very much.  I guess my reloading knowledge was not up to india specs!  I will pass this knowledge on to brother.  My loading has always been modern stuff where the case limit was when the neck split,  and that was only after many reloads and maybe a case trimming. SN