Effect of changing brass

[Iwsbull]

Do you notice any difference in poi, velocities, etc.... and do you think it matters more as you go to higher velocity and pressure?
The reason I ask is that I have a mixed bag of brass for my 44 magnum and at my favorite load,about 1280 FPS with a 265 grain swc, it doesn’t seem to matter a lot. When I load for upper end 454 casull it seems to make a very noticeable difference. When I used to load for my rifle I never mixed brass either.

 

[Blue68f100]

Mfg do not keep the same case volume. So some change in pressure is expected, yielding different velocities. The hardness varies too. Really noticeable in rifle brass.

 

[Slamfire]

Mfg do not keep the same case volume. So some change in pressure is expected, yielding different velocities. The hardness varies too. Really noticeable in rifle brass.

Want to add, cases vary by lot and by manufacturer. When you are running something like a 454 Casull, which runs at 60,000 cup, everything and anything will spike pressures. Maximum pressure of a 44 Magnum is 36,000 psia, which seems rather sedate compared to a 454 Casull. That trend, of increasing pressure, creates the conditions by which small changes make helliously high shifts in pressure, is true regardless whether the cartridge is a pistol cartridge, or a rifle cartridge.

I am of the opinion that accomplishing the same task at lower pressure is better than accomplishing the same task at higher pressure. Pressure is not your friend. It wants to hurt you, and it will, if you give it a chance. Remember those High School driver's educational films that were titled "Speed is not your friend"? Same idea applies. Higher pressures reduce margins and things go bad very quickly.

 

[Grumulkin]

Do you notice any difference in poi, velocities, etc.... and do you think it matters more as you go to higher velocity and pressure? The reason I ask is that I have a mixed bag of brass for my 44 magnum and at my favorite load,about 1280 FPS with a 265 grain swc, it doesn’t seem to matter a lot. When I load for upper end 454 casull it seems to make a very noticeable difference. When I used to load for my rifle I never mixed brass either.

The reason it doesn't matter with the 44 Magnum loads is probably because it is a bit less accurate than your 454 Casull. In a less accurate gun you're less likely to notice lapses in consistency.

In an accurate gun you will very frequently see a difference in POI, velocity and accuracy when using mixed brass. You will even frequently see a difference with new versus once fired brass of the same brand and lot.

 

[Varminterror]

Personally, I sort brass by headstamp, identify big batches of consistent brand/headstamp, confirm weights (sometimes different lots of the same brand can vary as wildly as different brands!), and then sell/trade the rest, or reserve them for different loads. I run my 44mags hot enough to give me pause to think about mixing headstamps. In a very mild load, eh, maybe, but what’s the point? I’ve rarely understood a paradigm where mixing brass makes sense - kinda like dumping 5-6 different brands of factory ammo into a bucket together, then loading mags randomly from the bucket - what are we doing with the pistol such there’s no importance given to consistency?

 

[Hondo 60]

Personally, I sort brass by headstamp,

+1 but Varminterror goes beyond what I do.