09-28-2022, 01:33 AM
LRRPF52 Wrote:When seasoned, older reloaders who put high load counts on brass say, This one gets up to 50 reloads and others dont even approach that., thats a pretty huge indicator of the quality of one brass over others.
Early-on with 6.5 Grendel, we had guys on the forum who got 20 or more loads with Lapua brass, shot the headstamps out. No other brass that Im aware of has achieved that many loads.
When I have shot and reloaded Federal 6.5 Grendel brass, for example, I lost primer pockets within 2 loads when shooting through the AR-15.
Interestingly, this did not happen when shooting and loading it through the Howa Mini bolt-action rifle. Even with me loading well over 1-2 grains higher than book loads in the AR-15, the primer pockets stayed nice and tight in the Howa with Federal brass.
Hornady brass has been the next-best performer for me in terms of longevity, number of reloads.
Other seasoned reloaders here on the forum have reported as many as 8-12 loads. Depending on what dies, pressures, gas system lengths, and chambers are used, you might see that brass become unusable at 5 loads.
This catastrophic failure happened with new Lapua brass on his first firing of that batch, #41 of 50 hand-loaded cartridges.
That brings me to the question, can we see the heads of the 40 other fired pieces of brass if we havent seen them already?
I understand all of this, but it doesn't necessarily mean that Lapua brass can't have a lot of reloads AND also it could have contributed to the issue. And it goes back to an earlier post where I stated that brass that is more malleable and elastic but also has lower hardness and yield strength than Lapua could have been a better brass in this specific failure case which is partially due to the M16 style feed cone depth issue. As stated before, a harder and higher yield strength brass is going to be more brittle than one that is more malleable and elastic with also lower hardness and yield strength. And so under extreme forces (i.e. pressure) the more brittle brass can simply snap and rupture, but a more malleable and elastic brass could stretch a little bit more than the harder and stronger one. This is entirely theoretically possible while also the same brass doesn't last as long with subsequent reloads.
And all this is in line with Lapua brass lasting so long! It literally resists deformation better than other brass, so it can be reused more often. I totally don't doubt this, but...I can also say that it could also be more susceptible to failing like it did than other brass as well. Due to it being slightly more brittle than other brass. With all metals and alloys you get this duality at times. There's no perfect one vs another. When you use one you likely have to make a tradeoff or compensation that another metal would provide. But then that metal might also have a different compromise.
I digress here but the making of samurai swords and carbon steel is a good example. Too much carbon and the steel becomes really hard, but then it is more brittle (less elastic). Take away some of the carbon, and it becomes less hard and more malleable and elastic. Same thing is going on with brass at different alloy compositions.