Effect of Brass on Accuracy/Velocity

[The_Champ]

I've heard of certain brands of brass having more longevity, requiring less trimming, etc.

Just wanted to ask the extensive knowledge of this forum if they have ever run into significant differences in accuracy, velocity, or other characteristics when using different brands of brass for the same gun/load.

When making plinking ammo and not to worried about accuracy, do you still separate your brass brands?

Thanks.

 

[Ganderite]

If you want max accuracy, you want each case to be as identical as possible in term of internal volume, neck tension, etc. This means starting with a batch of the same lot # of brass.

I would place Lapua and maybe Norma at the top of the list of quality.

For max velocity you want max internal volume, which means the lightest brass.

Military brass is generally the heaviest. well suited for military semi-auto rifles and general shooting.

I store ammo in 50 round plastic ammo boxes. For most shooting I sort the brass by whatever and keep it in a plastic box.

 

[Tompullings]

I saw a test where a guy shot groups with all identical brass and then groups with as many different head stamps mixed as possible. The mixed groups actually were slightly tighter on average than the single batch of brass.

Edit. Found it.

https://www.gunsamerica.com/digest/reloading-science-do-you-really-need-to-sort-your-brass/

 

[6MT]

.....

 

[cdn shooter]

Some brass is harder in the web, case head area which can be hotrodded a bit more. Lapua and winchester are quite hard. Some Hornady brass is extremely soft and will show crazy pressure signs on average loads. Lapua brass is extremely tough. I have some .308 that I turned into 7-08 that have 20+ firings on them.

As far as case volume, I’ve found the smaller cases to be more finicky, but really only as you get out further in range. 223 for FTR shooting needs to be very closely sorted for volume if you hope to do well

 

[bearhunter]

I saw a test where a guy shot groups with all identical brass and then groups with as many different head stamps mixed as possible. The mixed groups actually were slightly tighter on average than the single batch of brass.

Edit. Found it.

https://www.gunsamerica.com/digest/reloading-science-do-you-really-need-to-sort-your-brass/

This example is with a commercial, off the shelf grade chamber, in an AR15. The tolerances are usually quite generous. Therefore there wouldn't be much difference in accuracy. Not only that, the cases would have been full length resized, which in most cases isn't conducive to good accuracy.

When you're loading for a rifle with a tight match chamber or even a bolt action, hunting rifle, case consistency can make a very noticeable difference in accuracy.

One of the main differences, is that many folks only partially resize their cases or just the necks when they're going for accuracy.

Some people turn down the necks to get consistent tension on the bullet. I've never found this to be beneficial in an off the shelf rifle, other than it eliminates one more inconsistency. The neck areas of the chamber are already generous and this practice just allows for more expansion while firing.

When a custom chamber is involved, everything is tighter, some won't even accept factory ammunition. In this case, neck turning actually shows positive results, as does precision trimming to length.

Weighing brass can have beneficial results as well, even with factory chambers, but only if the shooter is fire forming the cases for use in a specific rifle and partial or neck resizing only.

 

[OR4NGE]

I’ve tested lapua, sig, hornady match , and FGMM brass . I’ve yet to measure an appreciable difference in accuracy over 4 5 round group of each headstamp with same load/primer/bullet ( 175gr tmk)

I will do further testing adding FLC and hirtenberger to the lot.

Keep in mind that all brass was prepped the same way and all the cheaper brass needed a lot more work with Flash hole uniform and other operations.

Best brass overall for requiring the least amount of work was lapua, followed closely by Sig, then FEderal GMM, then hornady.

 

[Buckmastr]

Using brass of the same fired internal volume results in consistent pressures and velocities. Weight sorted brass of the same manufacture and lot is the best way to accomplish this.

For a hunting rifle loaded to a moderate pressure, it may not be worth sorting brass.
I have had good luck with most brass manufacturers as long as I know what I'm dealing with.

 

[RifleDude]

I recently did a test to see if brass made a difference in accuracy. I loaded 10 rounds using six different case brands, all other things being the same. The loads were .223 Rem consisting of 55gr VMAX bullet, 26.8gr Varget, Federal 205M primers. Brass cases were: Winchester, Federal, Hornady, Remington, Lake City and IVI. I also loaded 10 rounds with mixed cases. The result was inconclusive. I could not see a significant difference in grouping. Strangely enough, the mixed case lot was slightly more accurate but only by a small amount. All cases were full length resized, cleaned, flash hole deburred, trimmed and case mouth chamfered. IMHO, cases are the last item to fine tune when working up accuracy loads. Can they make a difference? In really accurate rifles, I think they can maybe. Case prep is probably more important than the brand. For maximum accuracy, I do select cases by brand and weight.

 

[BCBRAD]

Lapua, out of 100 cases I weighed , checked volume etc. and got 7 that were identical, not to say the others varied much so segregated into 2 batches less the 7.

A sighter and a 3 shot group went 6.25" at 1038 yards, the rifle is an off the shelf Steyr Pro-Hunter in 7mm-08, 20"bbl.

I used H-4350 and a 150gn ELD-X @ 2606 ft/s, ES 5 ft/s.

I save these 7 brass for club shoots in hunter class.

 

[Chilly807]

I can say from experience that velocity may well be different from 1 brand to another.
When I was loading regularly for .243, I used three brands of brass.
Winchester had the largest internal volume, Lapua slightly less and Federal slightly less again.
With identical powder charges, Winchester was the slowest, Lapua was slightly faster, and Federal was the fastest.
Increased volume, probably as a result of a thinner case wall, means lower velocity in my experience.
For close range, non-critical shooting it doesn't make much difference as long as you're not pushing safe load limits.

 

[bigedp51]

I buy bulk once fired Lake City 5.56 and 7.62 brass because it is the hardest brass and above average in quality. Below are charts of .223/5.56 brass showing case weight, weight variations, capacity, and hardness. All my rifles are lower priced off the shelf factory rifles with SAAMI chambers. And I think you need higher priced or custom made rifles to see benefits with costly high quality brass. Meaning what benchrest shooters with custom made rifles do will have very little effect with an off the shelf factory rifles.

In 2005 I was given three 5 gallon buckets of Federal, Remington, and Lake City .223/5.56 brass fired by our local police dept. And the Lake City cases were far better in quality than the Federal or Remington brass. I kept buying the bulk once fired Lake City cases and stay with one brand of case. And I do not cry if I lose a case because they are a fraction of the cost of new cases.

Bottom line, I think the quality of your rifle, scope, and brass makes the biggest difference if you are shooting past 300 yards. And when you are standing on your hind legs shooting at a running deer at 40 yards it doesn't matter what brand of brass you use.

Below look at the case weight variations between the brands, and its the variations in case capacity that effects vertical dispersion at the longer ranges.

Read all of the link below, what is in blue below is only a small part of the article.


Save $$ By Using Lake City 5.56x45mm Once-Fired GI Brass
http://bulletin.accurateshooter.com/2019/10/save-by-using-lake-city-5-56x45mm-once-fired-gi-brass/

"Accuracy Potential of Mil-Surp 5.56×45 Brass
So, how accurate can previously-fired GI surplus brass be in a good National Match AR-15? Well, here’s a data point from many years ago that might be of interest. A High Power shooter who wrote for the late Precision Shooting magazine took a Bill Wylde-built AR match rifle to a registered Benchrest match. His first 5-round group ever fired in a BR match was officially measured at 0.231″ at 200 hundred yards. This was fired in front of witnesses, while using a moving target backer that confirmed all five rounds were fired.

He recounted that his ammo was loaded progressively with factory 52gr match bullets and a spherical powder using mixed years of LC brass with no special preparation whatsoever. Obviously, this was “exceptional”. However, he had no difficulty obtaining consistent 0.5-0.6 MOA accuracy at 200 yards using LC brass and a generic “practice” load that was not tuned to his rifle."