Percentage variation on case weights

[jpretle]

For those of you who weigh cases, how much variation do you find acceptable. For example, on case weights of
170g, do you accept a 4g variation??? or approx. 2.5%???

 

[stool]

its not a a percentages, tho you could work it out that way.

1000yd match brass...+/- 0.05
short range brass +/- .1
fun stuff, short range milsurplus..as small as i can get ...maybe +/- .2/.3

 

[jcampbellsmith]

For those of you who weigh cases, how much variation do you find acceptable. For example, on case weights of
170g, do you accept a 4g variation??? or approx. 2.5%???

On Remington 260 Rem brass which nominally weighed 162 gr I had some cases as low as 158.9 gr and some over 165 gr. I used to sort them in ~ 1 gr lots. There seemed to be two distinct lots in my brass and I've now moved it on. I've Nosler and Lapua brass now and I never even bother weighing it.

Regards

JCS

 

[stool]

what are you shooting ? caliber distance discipline ?/

For those of you who weigh cases, how much variation do you find acceptable. For example, on case weights of
170g, do you accept a 4g variation??? or approx. 2.5%???

 

[mikegaiz]

The year I set three IBS Heavy Gun 1000 yd. records my brass was sorted to + or-.5 gr. on Norma 300 WSM brass. ???

 

[stool]

just think if it had been .05 brass it might have been 5 or 6 records...

good shooting...the wind is not your friend at 1000 yds!

The year I set three IBS Heavy Gun 1000 yd. records my brass was sorted to + or-.5 gr. on Norma 300 WSM brass. ???

 

[stool]

for the number crunchers..
the 300wsm norma brass weighs around 247 , so .5 is 1 gr/247gr or 0.4%, or plus o rminus 0.2%

again great shooting...more the shooter than the ammo i think..

The year I set three IBS Heavy Gun 1000 yd. records my brass was sorted to + or-.5 gr. on Norma 300 WSM brass. ???

 

[mikegaiz]

Never rule out dumb luck, or the power of cleavage, but I digress... :

 

[jlow]

I am interested in hearing from you guys as to what weight variation will affect in reloading.

From my own standpoint, if you believe that weight variation = volume variation (and I know not everyone believes in this but to avoid getting bog down in THAT argument, you too could make your case as to what other effects it could have), then it could potentially affect chamber pressure and following that MV.

However, I’ve never seen it proven and more importantly that difference could move you out of an accuracy node. I do sort my brass by weight but only to keep case weight minimal within a group of reloading rounds. Mostly voodoo… ;D

 

[MFG_BOP]

Mr O'Hara, the 1000 yd agg record said: "I quit weighing cases because of the outside variations". Does he weigh internal volume? I dont think so. I would just scrap the brass in both extremes of the scale and have fun with the others IMHO.

 

[seymour fish]

Gents, Have recently gone down this road with Lapua 308 brass, and found that once prepped and fireformed, the water capacity was so close to exactly the same that a .005 difference in seating depth has a much greater magnitude pressure change on quickload. the cases varied a grain and a half heaviest to lightest, over 300 cases. Since they are already segregated by weights, I'll continue to run them that way. Dare me, and I'll dump them all together for 1K f-tr. Seymour

 

[Patch700]

Mr O'Hara, the 1000 yd agg record said: "I quit weighing cases because of the outside variations". Does he weigh internal volume? I dont think so. I would just scrap the brass in both extremes of the scale and have fun with the others IMHO.

Can't argue with that philosophy in my findings.... For a friendly reminder to myself once in a blue moon I will run designated fouler rounds (which are normally 3 tenths on either end of the weight spectrum and some that are a full grain under or over) into a group with my selected brass and low and behold... They go into the group if I do my part.

 

[langenc]

Kinda what I found with weighing 22 LR ammo.

Sort it to 0.2 gr variance. Then ran out with 3 or 4 shots to go on the target. I used some of the outliers and got all 10s w/ them??

Wasting my time weighing??

I do like to weigh and remove those on either side of the large group in the middle. Once in a while a round will be 0.6 grain or more off-it is a sighter/barrel dryer.

 

[jpretle]

seymore fish, in regards to Lapua 308 brass, given everything the same, EXCEPT LOT, would you dump them all together and use as one lot????

 

[jcampbellsmith]

seymore fish, in regards to Lapua 308 brass, given everything the same, EXCEPT LOT, would you dump them all together and use as one lot????

No. I've just loaded some 260 Rem rounds and one box of 50 rounds is from a different lot. I will keep the lots separate.

Regards

JCS