Brass stretch

[mugsie]

I shoot a lot of calibers, but really enjoy the 260 Rem. Well today I was FL sizing a bunch of brass of various head stamps and noticed some interesting facts.

First of all, what I do is clean, then anneal, the FL size, then trim, champher then clean again and they're ready for reloading. Well today I noticed that some brass required a lot more trimming than others.

I have Nossler, R&P, Lapua and a bunch of 243 that I sized up to use in my 6.5. The R&P brass required the most trimming, the 243 neck sized up the least and the Nossler and Lapua somewhere in between. This brass has all been shot multiple times in the same rifle.

Have any of you noticed this, that some brass typically requires more trimming than others, depending on head stamps?

Just curious as I don't seem to see this in my other calibers. At least not that I paid attention to.

Comments?

 

[OYE]

Yes, Several years ago noticed some brass stretched much more with the same loads. I assumed it's reloading life would be much reduced. So standardized on one brand of brass for the main calibers (when purchasing new brass). As an aside it was also noticed a substantial change of impact when using the stretchy brass and all else was equal. OYE

 

[gamestalker]

Yes, and no.

What I mean is if a chamber is producing unusual stretching issues like that, it might indicate you are bumping the shoulders back too far. And also, if you have brass that the shoulders have been inadvertently bumped to far, or it came from another rifle with a shorter chamber / head space, then seating the first batch with the bullet jammed into the lands will help control that. It forces the shoulder to blow out to the chamber, rather than the case head getting pushed back to the bolt face, which induces more body stretching, ultimately shortening the life span of the brass too.

FYI, if seating up too, or into the lands, you should take your load down to the low end of the table, at least until you have found the right powder charge that will accommodates the pressure increase, if any.

GS

 

[Sunray]

Annealing isn't necessary every time. Neither is trimming. You're making extra work for yourself. You only need to clean, check lengths and trim chamfer and deburr as required. Annealing is only done when one case cracks, usually at the mouth.
However, all brands are different. Some are harder than others. Federal, for example, is well known for being sifter than other brands. It only means it doesn't last as long before the primer pockets get too big.