How does brass affect accuracy?

[rootacres]

Can someone school me on this? Why is brass quality important? How does it affect accuracy? If I have say a 3/4 MOA rifle, would higher quality, more consistent brass knock it down to say a 1/2 MOA rifle?

If I am already case trimming, chamfer, de-burring, cleaning every piece of brass. Would I see a difference going to a more premium brand over Winchester?

 

[JMW67]

Brass is the foundation for your load as the slab is the foundation for a house if you start with crap you end up with crap yes it would most likely shrink your groups at long range I see you changed your thread a little if you are match prepping your win. brass then it will shoot as good as any brass just wont last as long

 

[CastIronSkillet]

From my non professional opinion is that higher quality or properly prepped brass could yield lower SD's by helping with consistent ignition. Lower SD's show better accuracy at distance but not so much at 100 yds. Flash holes and brass volume is much more consistent in quality brass.

 

[aushunter1]

Imho quality brass will last longer, be less prone(or take longer) to enlarge primer pockets & split neck.
But of course it still needs annealing.

Also the QC process would mean more consistant internal wall & web thickness case to case & also a more consistant weight case to case.

As @JMW67 say's its the foundation & all reloading is about consistancy.

All this mean better accuracy in the long run as long as the rest of your reloading regime is sound.

 

[GLTaylor]

Consistency is the key to good handloads/accuracy. It starts with the brass.

 

[DartonJager]

Let me put to you like this after being re-educated on many reloading subjects if I could I'd only buy Lapua Brass unfortunately my absolutely most favorite caliber Lapua Doesn't make brass for
Stumbled and I do mean Stumbled on a OIALTD on Norma Brass and bought it as everything I've read is if you can't get your caliber in Lapua brass Norma is your next best choice
I have used Hornady brass for my beloved 300 wsm and have been very satisfied but I've only shot to 300 yards with it so far but very impressive groups and good not great but good
SD and ES per my Caldwell chrono
Am very interested to see how tve New Norma Brass performs especially if it gives me the lower and minimal SD and ES I am trying to achieve
Because my reloads are at .5 moa or better and my SD and ES are still just a little high hoping better more consistent brass will help

 

[MagnumManiac]

It's not the brass, it's how it is finished and what volume it holds across the entire LOT.
Lapua is no better in this regard than any other brand, flash holes are still punched and require chamfering. Lapua lots do differ in volume, trust me on this.
Lapua brass, ADG, Winchester are all hard, this helps get STABLE brass sooner. It also takes to annealing well.
As long as volume, which is NOT to be confused with WEIGHT, then each shot should be very very close to each other in velocity and pressure.
It is this fact alone that makes or breaks brass cases.
Sure, turning necks, case trimming and neck tension play a role, but if the combustion isn't similar, neither will the end result no matter how uniform your necks are or how deep your primer is seated.

Cheers.

 

[DartonJager]

Feel free to correct me, and I sincerely mean it, if I error anywhere in the fallowing statements, but is not as I have read repeatedly the flash holes in Lapua brass need not be uniformed because they are drilled out and NOT punched like WW, FED, REM etc brass? And I have read at places like Precision Reloading and Accurate Reloading and here as well and other WS and even publications who's names escape me at this moment that Lapua brass is one of the most consistently manufactured brass available to standards of QC among the highest in the industry, higher than standard WW, REM. FED or the like brass. Hence the justification for much more expensive cost.
Is that true or was all just hype?
At least that is what I have read in more than just a few reloading information sources considered quite reputable.
Now I will grant you I have never owned Lapua brass only WW, REM, FED and Hornay brass so I was never able to do a S/S evaluation of Lapua brass VS the others I own and reload with so to be honest I have taken the word of Lapua's claims and the claims all of those who tout Lapua's superiority at face value.

I have done some thorough S/S comparisons of my new WW and Hornady brass in 300wsm (only new 300wsm brass I could ever find to buy for years, but just recently found a bunch of Norma) and the Hornady was more consistent in weight and volume and even length but not by a huge margin. Never saw a major difference in how clean or concentric the primer holes were between the WW and Hornady brass though. Also after 3 firings each didn't notice a dramatic difference in growth in head space measurements either.
Lastly is it just hype that although I do not know the exact number and will not say it a majority but I do know a large percentage of your bench rest competitors, PRS competitors use Lapua or other equally high quality brass and do not use what they consider lower end brass like WW FED or REM.
Not trying to argue just repeating what I have read published and heard stated repeatedly buy guys who shoot smaller groups at 300-600 yards than most guys shoot at 100-200.

 

[imyourhuckleberry]

The brass quality is important because this will allow for more consistent pressures in the chamber. It is about having the same internal and external dimensions throughout the lot so that if you load for example, 25 grains of powder, the powder fill the case to the same level for all the other cartridges. If there are inconsistencies in the internal and external dimension of the cases that could indicate a thinner wall or a thicker wall. If it is a thinner wall the case might expand faster sealing the chamber faster as well and the pressure chamber will affect the point of impact due to harmonics of the barrel. If the case has a thicker wall within the same lot that you are reloading than the case may take a few thousands of a seconds longer to completely expand and seal the chamber allowing for some gases to come back around the case reducing the chamber pressure slightly but enough to change the harmonics of the barrel. That is why you may have a flier in a shot group that could be high or low .

 

[DartonJager]

The brass quality is important because this will allow for more consistent pressures in the chamber. It is about having the same internal and external dimensions throughout the lot so that if you load for example, 25 grains of powder, the powder fill the case to the same level for all the other cartridges. If there are inconsistencies in the internal and external dimension of the cases that could indicate a thinner wall or a thicker wall. If it is a thinner wall the case might expand faster sealing the chamber faster as well and the pressure chamber will affect the point of impact due to harmonics of the barrel. If the case has a thicker wall within the same lot that you are reloading than the case may take a few thousands of a seconds longer to completely expand and seal the chamber allowing for some gases to come back around the case reducing the chamber pressure slightly but enough to change the harmonics of the barrel. That is why you may have a flier in a shot group that could be high or low .

You are absolutely correct and I believe consistent brass capacity is why many reloaders weight sort all their brass when new.
I saw a guy reloading for PRS state he uses liquid weight as measured by a 50/50 water alcohol mix to sort his brass VS weighing it empty. Have not tried that one yet. Can not see needing to as I only own 100% factory rifles.

Have any of you watched any of Eric "Speedy Gonzales" Cortina's videos on reloading? He is a nationally ranked national champion who has shot a 1.3" 1k yard group he openly admits was as much luck as skill. He has some very inciteful success/experienced based opinions on precision reloading and judging from his level of success he knows where of he speaks.
I highly recommend his videos. Very well done easy to understand.

 

[MagnumManiac]

Lapua cases are NOT drilled.
No case on the planet is drilled to make the flash hole, they are all punched. Period.
Ask Lapua directly, email them, they will tell you they do not drill flash holes.
Consistent brass comes down to the process of making it. All brass cases are either drawn in many dies, or extruded in fewer steps.
These two processes are different, one, extrusion, is more precise. Drawing always makes one side of a case thicker.
A case is good when it is hard enough in the head to withstand many firings and become stable, which means it has work hardened enough that several firings no longer make the case grow outward.
Annealing the neck after every firing is also the key.

Cheers.

 

[Savage 12BVSS]

I am a lapua user and find it to be the best brass I've used so far. Its uniform and weight sorts easily with no hassle. It holds tight primer pockets for longer and I don't care how they make the flash holes, they are always free of burs and hanging pieces of brass. I check every piece of brass for flash holes-weight-length-and neck thickness and uniformity. I don't volume check them because I don't competition shoot, I have slowly moved from norma brass to lapua in all cartridges and its quite a difference in quality, don't believe me check them and compare. I believe that there are other quality brands of brass out there as well, peterson and adg both have great brass too. It was discussed early this year about lapua brass being punched not drilled and a post by lapua rep was posted, but there is a lot of difference between norma and lapua in this area and its quite a pile of brass bits when you uniform norma brass vs lapua. And lapua come's with a nifty case holder box

 

[Plinker147]

Will higher quality brass shrink your groups? That answer is NO it may or may not help. If your only shooting groups at 100-300 yards it not show up. When you get out a distance over 600 yards that when those small difference show.

I have been able to shoot 3/4 MOA at 600 yds with several guns using hornady, rem, WW bras and never weight sort of work primer pockets.

If your looking for competition edges and accuracy then the high quality/ uniform brass is more important. If your looking a 3/4 MOA on your hunting rifle it's not necessary.

I do use high quality brass in some of my guns when it's available. It just removes one potential issue at distance

 

[emp1953]

Can someone school me on this? Why is brass quality important? How does it affect accuracy? If I have say a 3/4 MOA rifle, would higher quality, more consistent brass knock it down to say a 1/2 MOA rifle?

If I am already case trimming, chamfer, de-burring, cleaning every piece of brass. Would I see a difference going to a more premium brand over Winchester?

It could make that difference for you. Winchesters will work fine. If you mix head stamps you are asking for frustration when it comes to accuracy. Try an experiment yourself. Take several mixed headstamp cases in the same caliber. Clean them, trim them, size them. Then weigh them all. The differences you will see in weight, since the cases are supposedly all the same, length etc, is in the case wall, web thickness etc. These weight differences make the inside volume of the case differ. That volume relates directly to pressure. Pressure is what pushes the bullet out the barrel. If the pressure is not very nearly the same every time your POI will change, frustrating the dickens out of you. I was able to score on several thousand FC demilled cases in my 4 favorite calibers. During a convalescence following surgery I sized and deprimed and trimmed them all, weighed them all. Found a few that differed way too much from the average for me to be comfortable with so I tossed them in the scrap bucket. Those cases would have exhibited a significant difference in velocity hence a different POI, had I used them.