308 Winchester Case Weight by Manufacturer

robert harrison · July 22, 2014, 03:41 PM

As a cost conscious service rifle match competitor, I scavenge 308 Winchester / 7.62 x 51 mm range brass. I sort the brass by manufacturer, I size it, de-prime it, tumble it clean and weigh it.

The weight of brass and the uniformity of a manufacturer’s brass weight will influence chamber pressure and bullet velocity. Brass weight can also influence the cost of competing.

My accumulated stockpile of brass includes the following manufacturers: CBC (Companhia Brasileira de Cartuchos), Federal, GFL (Giulio Fiocchi), Hornady Match, Lake City Match (NM 68, NM 77 and Match 91) PMC (Eldorado Cartridge Corporation—previously Patton and Morgan Corporation and Pan Metal Corporation), PPU (Prvi Partizan) WCC (Western Cartridge Company), and Winchester. I have found very little RP, Norma or Wolf brass.

The Mean weight in grains of the listed manufacturers brass is as follows: Winchester at 157.13, Winchester nickel plated at 159.82, Hornady Match at 166.29, PPU at 166.94, Federal 308 WIN at 176.90, Lake City NM 68 at 177.55, Lake City Match 91 at 177.98, Lake City Match 77 at 178.45, GFL at 178.89, WCC at 179.48, PMC at 179.50 and CBC Nato 12 at 183.09.

As you can see Winchester’s mean weight is the lightest at 157.13 grains, even when nickel plated it only weights 159.82 grains, and CBC Nato 72’s mean weight is the heaviest at 183.09 grains. That is a range of 25.95 grains.

These weights are important because the American Rifleman recommends that powder charge be reduced by 1 grain for every 11 grains of empty case weight. This translates as 17 grains more brass weight requires 1½ grains less powder. For example if I am loading 42 grains of IMR 4895 in a Winchester brass—mean weight of 157 grains—and switch to Federal brass—mean weight of 176 grains—I should reduce my IMR 4895 load to 40.5 grains to avoid excess chamber pressure.

There are 7000 grains in one (1) pound of IMR 4895 which costs about $30. Therefore with a 40.5 grain load, I can get 172 rounds at $.17 each with a 42 grain load I can get 166 rounds at $.18 each in powder cost.
Accuracy is influenced by consistency. A wide variation in weight of a specific manufacturer’s brass may influence the consistency of camber pressure and thus bullet velocity.

The weight Standard Deviation by manufacturer is as follows: Federal 308 WIN at .633, GFL at .635, Lake City Match 91 at .691, WCC at .755, PMC at .873, Lake City NM 68 at 1.072, Winchester nickel plated at 1.083, Lake City Match 77 at 1.083, PPU at 1.462, CBC Nato 12 at 1.557, Winchester at 1.911, Hornady Match at 2.342.

The weight Standard Deviation is lowest for Federal at .633 with GFL close at .635 and highest for Hornady Match at 2.342. It appears Federal has a more uniform weight and Hornady Match has the least uniform weight. If uniform weight is an indication of uniform case capacity, then Federal is the most uniform and Hornady Match is the least uniform.

Shot to shot consistency is important when competing. If uniform brass weight means uniform case capacity then chamber pressure and bullet velocity will produce more consistent—accurate—ammunition.

According to Brownells’ website, Federal 308 Winchester goes for $26 per 50 or $. 52 per and Hornady 308 Winchester Match goes for $35 per 50 or $ .70 per.

Federal brass is less expensive, has greater weight uniformity and less case capacity which means I can get the velocity I need with a smaller powder charge. For an 800 point service rifle match, I can use rounds that cost $ .69 per round using Federal brass as opposed to $ .88 per round with Hornady Match. That will save me $16.72 per match. The cost of bullets and primers are not factored into this cost.

This is in no way a scientific survey nor can inferences be deduced from my findings, but it might be useful to service rifle competitors and the re-loading community.

Bart B. · July 22, 2014, 04:39 PM

Good post; excellent info on all those makes and types.

Out of a few dozen makes of .308 Win cases with weights from 150 grains (WCC58 match) to 180 grains (I forget the make, now) used for reloading, my first choice of any would be based on the uniformity of their wall thickness if accuracy is the number one objective. A 1 to 2 grain increase in charge weight increase with a light weight case to get a bit more velocity is way down on my ammo's objectives list.

Uniform wall thickness means neck wall thickness is uniform. It also means the wall thickness all the way back to the case head is uniform. Which means the cases will stretch uniformly all the way around so the case head hits the bolt face uniformly all the way around it after being driven full forward in the chamber when fired. Otherwise, the case head hitting the bolt face off center tends to make the barreled action whip and vibrate in a different direction. Bullets leave the muzzle axis in a direction that makes them strike away from the point of aim.

The most uniform wall thickness' I've seen across several makes of .308 Win or 7.62 NATO cases are those made for the US International Team's 300 meter free rifles; Western Cartridge Company's WCC58 headstamped 150-gr. cases. 99% of them have wall thickness even/uniform enough all the way around to make a fired case pressure ramp (the 1/10th inch wide pressure ring from extractor groove to its largest diameter where the "pressure ring" is typically related to shown on the right in the picture below):

No wonder these cases were used winning most of the matches and setting most of the records at long range from .308 Win. cases in the heyday of match rifles chambered for that round.

The case on the left shows the opposite side of that same case with no pressure ramp at all; it's the thickest part of the case wall. Uniform walled cases have the same pressure ramp all the way around. My WCC58 brass has 99% of all cases' pressure ramp the same all the way around; neck wall thickness spread is less than .0005". My Remington .308 Win. BR small rifle primer cases like the one shown have about 95% uniform ramps/wall thickness. Arsenal cases, including Lake City Match, are typically not all that good, but some of the Lake City National Match ones have been at about 93% uniform.

One thing I (and many others) have observed reloading fired cases for service rifles; they don't shoot as accurate as new ones. No service rifle I know of has their bolt face squared up with the chamber axis. The US Army Reserve Team did extensive tests decades ago reloading once fired commercial and arsenal match cases from their M14NM competition rifles. None of the reloaded cases shot as accurate as new ones. Their heads were smashed out of square the first time fired and smacked one side of the bolt face first the next time they were fired. Accuracy degraded by about 50% compared to the same cases when new. Most of the accuracy loss was shot stringing from 7 to 1 o'clock on paper as the M14 bolt's lugs locked up at 10 and 4 o'clock. Less stringing was at 10 and 4 o'clock as the most case head support was at those points aligned with the closed bolt's lugs. Resizing those cases did not square up their heads.

I don't think a small spread in case weight has much effect on accuracy. Many thousands of rounds of .308 Win. Federal Gold Medal Match fired in both M1 and M14 rifles rebuilt the right way would shoot inside 4 inches at 600 yards. Case weight spread was 3 or more grains, bullet runout as many thousandths and charge weight as many tenths of a grain. The same spreads in handloaded new cases has produced 3 inch or better accuracy in bolt action rifles shooting .308 ammo.

AllenJ · July 22, 2014, 05:47 PM

Good information. Your view on the thicker brass saving powder is something that has never occurred to me, interesting observation. Also the brass weights help confirm to me of the brands I don't want to consider purchasing in the future.

T. O'Heir · July 23, 2014, 04:16 PM

"...scavenge 308 Winchester/7.62 x 51 mm range brass..." Quit doing that. You have no idea what has been done to any of it, how many times it has been loaded or anything else. And 7.62 brass will have crimped primers. Not a big deal, but it is a nuisance if you mix 'em with commercial.
Other than that it really makes no difference for regular match shooting. Bench rest shooting is different.

Bart B. · July 23, 2014, 04:34 PM

T. O'Heir, I think it does make a difference. Especially when folks using good cases in regular match rifles fired off their shoulders in position matches get accuracy testing loads equal to what the benchresters do with a rifles rested atop a bench at the 300 to 1000 yard ranges used in both disciplines.

WESHOOT2 · July 25, 2014, 05:18 PM

I would only point out that some guns might prefer a certain brand case.....

Bart B. · July 25, 2014, 11:13 PM

I've heard for decades that some rifles 'prefer' certain brands of cases. None of 'em has ever explained how a rifle 'knows' the brand of case that's in its chamber. Without a brain and nervous system to know and discriminate what the rifle likes, I'm not believing that at all.

Having shot many makes and weights of cases, as long as the were all of equal high quality, accuracy was equal across them all.

4runnerman · July 25, 2014, 11:27 PM

At the fear of getting beat up on this one I will say anyhow. I have never sorted brass by headstamp. I do sort by weight. I keep my 308 ( and all my brass for that matter) with in 2/10 gn weight after deprimed,sized,trimmed, and chamfered. Never noticed a big difference in POI. For my matches I use Lapua Brass any how.

Bart B. · July 27, 2014, 09:36 AM

4runner, the Accuracy Police will be knocking on your door holding a pair of handcuffs just your size in one hand and a subpoena in the other. Not supposed to release to the public that case weight uniformity is more important than what's stamped on case heads. Call a good lawyer; quick.

I'm sorry, but I called them after reading your post.

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July 22, 2014, 03:41 PM	#1
robert harrison Junior Member Join Date: June 6, 2012 Location: Fort Lauderdale, FL Posts: 1	308 Winchester Case Weight by Manufacturer As a cost conscious service rifle match competitor, I scavenge 308 Winchester / 7.62 x 51 mm range brass. I sort the brass by manufacturer, I size it, de-prime it, tumble it clean and weigh it. The weight of brass and the uniformity of a manufacturer’s brass weight will influence chamber pressure and bullet velocity. Brass weight can also influence the cost of competing. My accumulated stockpile of brass includes the following manufacturers: CBC (Companhia Brasileira de Cartuchos), Federal, GFL (Giulio Fiocchi), Hornady Match, Lake City Match (NM 68, NM 77 and Match 91) PMC (Eldorado Cartridge Corporation—previously Patton and Morgan Corporation and Pan Metal Corporation), PPU (Prvi Partizan) WCC (Western Cartridge Company), and Winchester. I have found very little RP, Norma or Wolf brass. The Mean weight in grains of the listed manufacturers brass is as follows: Winchester at 157.13, Winchester nickel plated at 159.82, Hornady Match at 166.29, PPU at 166.94, Federal 308 WIN at 176.90, Lake City NM 68 at 177.55, Lake City Match 91 at 177.98, Lake City Match 77 at 178.45, GFL at 178.89, WCC at 179.48, PMC at 179.50 and CBC Nato 12 at 183.09. As you can see Winchester’s mean weight is the lightest at 157.13 grains, even when nickel plated it only weights 159.82 grains, and CBC Nato 72’s mean weight is the heaviest at 183.09 grains. That is a range of 25.95 grains. These weights are important because the American Rifleman recommends that powder charge be reduced by 1 grain for every 11 grains of empty case weight. This translates as 17 grains more brass weight requires 1½ grains less powder. For example if I am loading 42 grains of IMR 4895 in a Winchester brass—mean weight of 157 grains—and switch to Federal brass—mean weight of 176 grains—I should reduce my IMR 4895 load to 40.5 grains to avoid excess chamber pressure. There are 7000 grains in one (1) pound of IMR 4895 which costs about $30. Therefore with a 40.5 grain load, I can get 172 rounds at $.17 each with a 42 grain load I can get 166 rounds at $.18 each in powder cost. Accuracy is influenced by consistency. A wide variation in weight of a specific manufacturer’s brass may influence the consistency of camber pressure and thus bullet velocity. The weight Standard Deviation by manufacturer is as follows: Federal 308 WIN at .633, GFL at .635, Lake City Match 91 at .691, WCC at .755, PMC at .873, Lake City NM 68 at 1.072, Winchester nickel plated at 1.083, Lake City Match 77 at 1.083, PPU at 1.462, CBC Nato 12 at 1.557, Winchester at 1.911, Hornady Match at 2.342. The weight Standard Deviation is lowest for Federal at .633 with GFL close at .635 and highest for Hornady Match at 2.342. It appears Federal has a more uniform weight and Hornady Match has the least uniform weight. If uniform weight is an indication of uniform case capacity, then Federal is the most uniform and Hornady Match is the least uniform. Shot to shot consistency is important when competing. If uniform brass weight means uniform case capacity then chamber pressure and bullet velocity will produce more consistent—accurate—ammunition. According to Brownells’ website, Federal 308 Winchester goes for $26 per 50 or $. 52 per and Hornady 308 Winchester Match goes for $35 per 50 or $ .70 per. Federal brass is less expensive, has greater weight uniformity and less case capacity which means I can get the velocity I need with a smaller powder charge. For an 800 point service rifle match, I can use rounds that cost $ .69 per round using Federal brass as opposed to $ .88 per round with Hornady Match. That will save me $16.72 per match. The cost of bullets and primers are not factored into this cost. This is in no way a scientific survey nor can inferences be deduced from my findings, but it might be useful to service rifle competitors and the re-loading community.

July 22, 2014, 04:39 PM	#2
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Good post; excellent info on all those makes and types. Out of a few dozen makes of .308 Win cases with weights from 150 grains (WCC58 match) to 180 grains (I forget the make, now) used for reloading, my first choice of any would be based on the uniformity of their wall thickness if accuracy is the number one objective. A 1 to 2 grain increase in charge weight increase with a light weight case to get a bit more velocity is way down on my ammo's objectives list. Uniform wall thickness means neck wall thickness is uniform. It also means the wall thickness all the way back to the case head is uniform. Which means the cases will stretch uniformly all the way around so the case head hits the bolt face uniformly all the way around it after being driven full forward in the chamber when fired. Otherwise, the case head hitting the bolt face off center tends to make the barreled action whip and vibrate in a different direction. Bullets leave the muzzle axis in a direction that makes them strike away from the point of aim. The most uniform wall thickness' I've seen across several makes of .308 Win or 7.62 NATO cases are those made for the US International Team's 300 meter free rifles; Western Cartridge Company's WCC58 headstamped 150-gr. cases. 99% of them have wall thickness even/uniform enough all the way around to make a fired case pressure ramp (the 1/10th inch wide pressure ring from extractor groove to its largest diameter where the "pressure ring" is typically related to shown on the right in the picture below): No wonder these cases were used winning most of the matches and setting most of the records at long range from .308 Win. cases in the heyday of match rifles chambered for that round. The case on the left shows the opposite side of that same case with no pressure ramp at all; it's the thickest part of the case wall. Uniform walled cases have the same pressure ramp all the way around. My WCC58 brass has 99% of all cases' pressure ramp the same all the way around; neck wall thickness spread is less than .0005". My Remington .308 Win. BR small rifle primer cases like the one shown have about 95% uniform ramps/wall thickness. Arsenal cases, including Lake City Match, are typically not all that good, but some of the Lake City National Match ones have been at about 93% uniform. One thing I (and many others) have observed reloading fired cases for service rifles; they don't shoot as accurate as new ones. No service rifle I know of has their bolt face squared up with the chamber axis. The US Army Reserve Team did extensive tests decades ago reloading once fired commercial and arsenal match cases from their M14NM competition rifles. None of the reloaded cases shot as accurate as new ones. Their heads were smashed out of square the first time fired and smacked one side of the bolt face first the next time they were fired. Accuracy degraded by about 50% compared to the same cases when new. Most of the accuracy loss was shot stringing from 7 to 1 o'clock on paper as the M14 bolt's lugs locked up at 10 and 4 o'clock. Less stringing was at 10 and 4 o'clock as the most case head support was at those points aligned with the closed bolt's lugs. Resizing those cases did not square up their heads. I don't think a small spread in case weight has much effect on accuracy. Many thousands of rounds of .308 Win. Federal Gold Medal Match fired in both M1 and M14 rifles rebuilt the right way would shoot inside 4 inches at 600 yards. Case weight spread was 3 or more grains, bullet runout as many thousandths and charge weight as many tenths of a grain. The same spreads in handloaded new cases has produced 3 inch or better accuracy in bolt action rifles shooting .308 ammo. Last edited by Bart B.; July 22, 2014 at 05:38 PM.

July 23, 2014, 04:34 PM	#5
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	T. O'Heir, I think it does make a difference. Especially when folks using good cases in regular match rifles fired off their shoulders in position matches get accuracy testing loads equal to what the benchresters do with a rifles rested atop a bench at the 300 to 1000 yard ranges used in both disciplines. Last edited by Bart B.; July 23, 2014 at 10:32 PM.

July 22, 2014, 05:47 PM	#3
AllenJ Senior Member Join Date: December 11, 2009 Location: Northern California Posts: 1,766	Good information. Your view on the thicker brass saving powder is something that has never occurred to me, interesting observation. Also the brass weights help confirm to me of the brands I don't want to consider purchasing in the future.

July 23, 2014, 04:16 PM	#4
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...scavenge 308 Winchester/7.62 x 51 mm range brass..." Quit doing that. You have no idea what has been done to any of it, how many times it has been loaded or anything else. And 7.62 brass will have crimped primers. Not a big deal, but it is a nuisance if you mix 'em with commercial. Other than that it really makes no difference for regular match shooting. Bench rest shooting is different.

July 25, 2014, 05:18 PM	#6
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	I would only point out that some guns might prefer a certain brand case.....

July 25, 2014, 11:13 PM	#7
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	I've heard for decades that some rifles 'prefer' certain brands of cases. None of 'em has ever explained how a rifle 'knows' the brand of case that's in its chamber. Without a brain and nervous system to know and discriminate what the rifle likes, I'm not believing that at all. Having shot many makes and weights of cases, as long as the were all of equal high quality, accuracy was equal across them all.

July 25, 2014, 11:27 PM	#8
4runnerman Senior Member Join Date: January 16, 2010 Location: Minnesota Posts: 3,577	At the fear of getting beat up on this one I will say anyhow. I have never sorted brass by headstamp. I do sort by weight. I keep my 308 ( and all my brass for that matter) with in 2/10 gn weight after deprimed,sized,trimmed, and chamfered. Never noticed a big difference in POI. For my matches I use Lapua Brass any how.

July 27, 2014, 09:36 AM	#9
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	4runner, the Accuracy Police will be knocking on your door holding a pair of handcuffs just your size in one hand and a subpoena in the other. Not supposed to release to the public that case weight uniformity is more important than what's stamped on case heads. Call a good lawyer; quick. I'm sorry, but I called them after reading your post.