Stretched .45-90 brass

[Woody]

I have had cases stretch, "but knock on wood," have never had one split in two. Some of my W-W 45-70 brass is at least 25 years old and now is showing the occasional longitudal split. The brass is still capable of fine accuracy after too many cycles to count in multiple chambers. My Starline 45-90 brass stretches to a greater degree than any other brass I have. Annealing the Starline brass slows and reduces the stretching. For years, I was a die-hard blow-tuber and my 45-70 brass never needed trimming. My 45-90 usually stretched approximately 5 to 10 thousands each firing requiring trimming. The only time I experienced excessive stretching was when I experimented with breech seating and a full uncompressed case of powder. Excellent accuracy, but cases sometimes stretched as much as 50 thousands of an inch. A few cases even showed splitting around the circumference but did not quite separate. I developed a method of compressing the powder and still have a full case and the stretching stopped. I have also found the case stretching can occur with hard and oversized wads of LDPE, HDPE, and dense fiber material. Finally wet and or oily chambers seem to be the culprit now that I have embraced the bore pig method. Both my old W-W 45-70 and my not so old 45-90 frequently require length attention after a match and prior to reloading. I have observed numerous shooters that seem to have multiple case separations, but can not see a common denominator. Your results may vary, but I have found for me that as long as I compress the powder some, have a LDPE wad that fits the case properly, anneal Starline brass at least one time, and finally have a dry chamber, I will not have case separation issues and can spend my time on other things.

Woody

[RB1Shooter]

Good comments Woody, thank you.

I have had a couple "almost case separations" with Starline brass. In these instances, I found the case ~.005" - .006" longer than chamber length; measuring rim to mouth where it had not separated. I blow tube yes but water not the issue. Chamber oil / lube possibly but I don't think so. What I am I am thinking is that maybe my case lip peened in and I did not catch it. I normally seat bullet and apply .001" neck tension. I am now wondering if the peened in case lip grabbed into the bullet when I applied the neck tension and when I fired, it stretched the case into the chamber mouth?

Using the Ulsher stuck separated case removal procedure made removing quick and easy but, who wants to deal with a case separation during a match.