.243 Win Brass Comparison Test — Surprising Results
A while back, Forum member Andy (aka GrayMist) did an interesting test, with five (5) different types of .243 Winchester Brass. He collected Federal, Lapua, Remington, and two different lots of Winchester-brand brass. Then he selected ten (10) cases at random from each brand and measured their weights. To ascertain case capacity, three (3) cases from each brand/lot that were closest to the average weight for that brand/lot were selected. The results were surprising: there was less than one (1) grain capacity difference between all the cases, even with a 14.7 grain maximum difference in case weight!
Measuring Procedures
The cases were sized in a Redding body die then primed with a spent primer. All were weighed before and after filling them with distilled water. The capacity shown is an average of all three (3) cases from that lot and represents grains of water. Note, I tested two lots of Winchester brass. Lot A was purchased in 1999. Lot B was from factory .243 ammo. There is a rather large disparity in case weight between the two lots.
| Brand | Federal | Lapua | Remington | Winchester A | Winchester B |
| Capacity | 53.9 | 54.4 | 53.7 | 54.8 | 54.8 |
| Aver. Weight | 173.28 | 173.13 | 165.34 | 158.58 | 166.44 |
| SD¹ | 0.46 | 0.39 | 0.17 | 0.58 | 0.42 |
| Range² | 1.70 | 1.10 | 0.40 | 1.80 | 1.40 |
| % of Avg.³ | 0.98% | 0.64% | 0.24% | 1.14% | 0.84% |
1) Standard Deviation in grains.
2) Range is the difference in weight between the heaviest and lightest cases in the test.
3) Case range weight divided by the average weight.
What the Numbers Mean
… And Some Speculations
Andy observes: “It certainly seems there is a huge difference in case weight between Winchester lot A and any other brand of 243 tested. What is also surprising is that there was less than one (1) grain capacity difference between all the cases, even with a 14.7 grain difference in case weight!
Should one be wary of trying the same loads that were initially tested in the light weight Winchester brass even though the capacity difference is small? I have had some interesting results with one brand brass that I cannot pass on yet, except to say I sent that company a sample of the lot I have been using. The Remington brass weight range was very low. These were taken from a box of once-fired factory ammo. I will have to acquire some more and measure it.”
Results of Larger Lapua Sample
In a previous session Andy weighed all 100 Lapua cases he had on hand. His measurements showed a total variation of 2.1 grains, with the weight range being 172.5 to 174.6 grains. That is a 1.2 percent spread. The most that came in at the same weight were 11 cases at 173.5 grains.
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Tags: .243, 6mm, Brass, Federal, Lapua, Remington, Winchester
Interesting analysis, but misses out some key information. For example what scales were used and what tolerance do these scales measure to?
I can only say I use 243 Win brass as the base brass to make my 6mm Super X brass and I have made it from Lapua, Remington, and Winchester brands of brass. I won’t dispute that weight sorting Winchester brand brass is advisable for high accuracy target shooting. I also prefer Winchester brand 243 brass over over all the others. If you weight sorted batches and pitch out an occasional case you cull for a visible quality issue (as you would do with any brand of brass), I think Winchester has better than or equal quality to all of them and it is also the hardest and handles pressure the best. Winchester brand 243 brass is also one of the least expensive as well, so if you have to pitch out a few cases here or there, no big deal.
Robert Whitley
My data:
Fed 179.0 gr ave case weight over 300 cases.
Frontier 163.2gr over 200 cases
Rem 166.5 gr over 700 cases
PMC 190.0 gr over 100 cases
Lapua 171.6 gr, 53.1 gr cap over 100 cases
Norma 169.0 gr, 52.9 gr cap over 100 cases
I also have Win and Lake City around somewhere.
The Remington has batches from 1980 and 2000 the PMC is all from 1980. All the brass from the 80s has been shot and annealed more than 20 times.
I don’t shoot max loads anymore, not since I first started. All cases seem to handle normal loads in a bolt action just fine. The PMC seems to work better in the AR. I rarely shoot .15″ groups but with the exception of the Frontier & PMC brass the groups are very close in average size.
I’d suggest the results show that weight sorting brass is a waste of time(which I believe). But, your results also imply that capacity checks are a waste of time..
Something’s amiss about this testing, that needs qualifying.
Why was the brass sized before the test?
Were the cases all NEW, or Fireformed to the same chamber?
Were the pockets & flash holes uniform and primers qualified by weight, height, and seated te same?
Were the necks trimmed to the same length?
What information is concealed in the ‘averaging’?
I’m amazed(and suspicious) that the capacity spread among these cases was so low. I have not seen capacity spread so low with lots of Lapua, Norma, and Tubbs in 223, 6br, or 6xc. But have had similar results only with different lots of Win WSSM reloading cases(the best brass I’ve seen to date).
To qualify my testing is always on fully fireformed/unsized cases, which I scale stand on a plastic golf tee.
The above criticism aside, we should all thank the author for actually having done something and published his results. For those who disparage his data – where’s yours?
Just came across this article as I am starting to do more rifle shooting after years as Bullseye shooter.
I used an RCBS digital scale that has 0.1 grain of accuracy for this test.
I purchased Nosler Brass N=50 and all testing was conducted as it came from the factory without any further modification.
The statistics included mean 174.6 grains, ave. dev 0.21 with min of 174.2 and max of 175.2 and percent of ave. 0.57 which appears to be better than the statistics for brass tested by the author.
The Nosler brass is advertised as manufactured at the factory with uniform primer pockets, chamfered necks and cut to length which upon observation can be seen with the naked eye.
I then tested case volume for min, max and ave. case weights with each being very close at 52.0, 52.2 and 52.3 which means probably that for small cases weight does not necessarily translate into large volume differences say for example a 300 Winchester Magnum. I am wondering how much difference in accuracy can case weight make for smaller cases?
I also am planning to look at overall length, neck size and neck inside diameter which may tell more about accuracy.