Brass is brass is brass?

I was listening to a conversation at a local match regarding which brass to use in reloads and a HM and a M were both instructing a MM to get used to using "quality brass" like Starline and not mixed brass casings for reloads. While I have read just about all the comments here about when to retire brass and all that, I just can't help but wonder why one brass casing is better than another? Are they all not held in a tight-fitting chamber when fired? How would one type over another affect accuracy in any way? It just seems counterintuitive. While the LOAD would certainly affect accuracy, how does the little brass cup do so?

The o.d's are the same, the i.d's are not causing uncontrollable variances in volume. not a good thing for accuracy...

Bullseye is about shot to shot consistency, as to good or bad brands ive only heard of a couple that people said stay away from, one was Amerc and the other I forgot but it wasn't a major brand either and of course don't use the cheap steel stuff. so if you use all the same head stamp you will be fine. Mixing them at 25 yards will still not make a big difference, and some say mixed brass doesn't have an effect at all. I choose to shoot all the same headstamp in a match.

I personally wouldn't sweat it until I was shooting HM scores. I'm not saying do not load good ammo, but I wouldn't kill myself and spend the extra money until then. My reason is based on several things, but here is one example. I built a pistol for a fellow shooter. His groups were 1.25" with Nosler 185 jacketed and new brass. 1.5" with Noslers and assorted brass. 2" with LSWC and assorted brass. All groups shot at 50 yards with Ransom Rest. Most shooters cannot tell the difference between all these loads until shooting HM. Last time I broke 2600 was with range lead cast bullets and assorted brass. Unfortunately not too many shooters shooting that good with new Starline and Noslers/Zero bullets. I would let my scores dictate whether to shoot new brass or not. So in other words, don't break the bank trying to get better scores. Spend more time shooting and aquiring BE skills. Then when your performance level is getting near the top get the new brass.
Jon

bogierich wrote:"quality brass" like Starline and not mixed brass casings for reloads.  I just can't help but wonder why one brass casing is better than another? Are they all not held in a tight-fitting chamber when fired? How would one type over another affect accuracy in any way?

Headspace is a much over looked part of the accuracy game. Starline is the longest of all brass..and if the barrel is chambered to compliment the brass, accuracy will  be enhanced.   You can use mixed brass at short line, but serious long line deserves attention to all the minor details.. Brass is just one of those details... Long,  brand new, Starline brass will have little effect without attention to barrel chamber dimensions..

I'm not that great of a shot, but I do not mix headstamps for 50 yard shooting.

NRA tested this theory in the 60s or 70s in a very accurate .44 Mag revolver. Matched headstamps were like 1.5 inches at 25 yards (indoor range testing), mixed headstamps were twice that size.

I'm sure that translates to other calibers as well. Headstamps won't matter if your XYZ and ABC are both made by the same company to the same specs and just private labeled out with different markings. But I don't know who makes what for whom these days.

What worries me more is something I read in Shooting Sports USA years ago about the then-new AMU load with Nosler 185s and one of those overpriced Scandinavian powders--noticeable falloff in accuracy after about four firings, IIRC. I'll need to accuracy check again, but all of my .45 stuff is on its 3rd or 4th firing right now...