Cabin fever and bordum.

[Beekeeper]

OK I have it bad.
So Bad I have begun to weigh brass .

Which leads me to the question I have.
I shoot a lot of 7x57MM Mauser.
Back when I started ( don't ask when) I formed all of my brass from LC63 Match brass.
Weighed a lot of it today and get as much as a 5 grain span in weight.
As I am always trying to get better and better groups how much diference would the 5 grain span make ?

All else staying the same
ie:
boolit
primer
powder charge

Would the 5 grain diference make that much change?

[Bullshop Junior]

It will make a differance. Most of my targer shooting brass was weight sorted to within 1/2gn, but but my hunting plinking ammo. Alot of my targets I shot for plstal matches were one case used over and over.

[btroj]

When I was shooting high power I never sorted by weight. I sorted by neck runout. Less than a thousandth and it was 600 yard case, one thou or so and it was 200/300 yard case. The few over two thou and it was trash.

[Ron in PA]

To make a big differance is to remove internal flash-hole burrs.

[Harter66]

I had this 06' ............
Depending on the rifle it can make a huge difference . I acquired a lot of 125 LC43 factory "fresh" and took my trusty 1965 110 to the range after about 10 rounds I noticed the scope had moved and a 16" group. I took it home put the scope back where it was supposed to be and shot it again this time there were 2-3 right together then 2-3 over a little ways but together and the rest of the 10 all over . I went home checked all the mount and ring screws for tight and bedded the action, and repeated the 2-3 and scattered groups. I bought a new scope and repeated the check mounts and rings only to repeat the groups . More or less I decided to just empty the brass of the remaining lot of 80 or so. I practiced breathing hold squeeze as there was no point in wasting the range time. What appeared were 3 very distinct groups separated by about 8" and a 6-7 flyers. I did a water volume weight and found 2gr of difference and a light case at 189.? and a heavy at 207.? I also found 3 groups of cases that were w/in 1gr and plus 3-4 of the flyers from that last day of shooting that were very light or heavy. The 1 gr lots were about 2-3 gr apart being 192,194,198gr IIRC. I scale all the brass now when I start new lots,it just eliminates 1 reason for "why the HHHH is that 1 out there". Although I will also admit that w/sub 1200 fps Unique loads the odd lots seem to work fine as long as I keep them w/in lots of heavy or light IG up to 191 or above 199 treated as separate lots.

[Beekeeper]

Thanks for the answer Harter66.
That is about what I thought but needed to confirm it with someone else.
I am always looking for some way to make my shots a little better.
That and bordum are the reasons for even weighing the brass.
Since I do not shoot long distance I guess the 4-5 grain diference will not make that much diference with cast boolits.
Again thanks all for the info.


beekeeper

[762 shooter]

Boredom.

I'm bored.

762

[bgokk]

I had this 06' ............
Depending on the rifle it can make a huge difference . I acquired a lot of 125 LC43 factory "fresh" and took my trusty 1965 110 to the range after about 10 rounds I noticed the scope had moved and a 16" group. I took it home put the scope back where it was supposed to be and shot it again this time there were 2-3 right together then 2-3 over a little ways but together and the rest of the 10 all over . I went home checked all the mount and ring screws for tight and bedded the action, and repeated the 2-3 and scattered groups. I bought a new scope and repeated the check mounts and rings only to repeat the groups . More or less I decided to just empty the brass of the remaining lot of 80 or so. I practiced breathing hold squeeze as there was no point in wasting the range time. What appeared were 3 very distinct groups separated by about 8" and a 6-7 flyers. I did a water volume weight and found 2gr of difference and a light case at 189.? and a heavy at 207.? I also found 3 groups of cases that were w/in 1gr and plus 3-4 of the flyers from that last day of shooting that were very light or heavy. The 1 gr lots were about 2-3 gr apart being 192,194,198gr IIRC. I scale all the brass now when I start new lots,it just eliminates 1 reason for "why the HHHH is that 1 out there". Although I will also admit that w/sub 1200 fps Unique loads the odd lots seem to work fine as long as I keep them w/in lots of heavy or light IG up to 191 or above 199 treated as separate lots.

Your post got me to thinking:groner: and with our snow and ice (bored). I weighed a batch of FC .223 cases (88 ct.). Once fired brass cleaned but not resized nor trimmed.

Boy was I surprised! The weight ran from a low of 94.7 grains to a high of 96.6 grains. I was not expecting that much difference.
61 cases are between 95.6 and 96.2 grains. I wonder how 0.6 grain difference will effect groups? These 61 fall into two 0.3 grain groups lite group 95.6/95.8 heavy group 96.0/96.2.

When the weather and range conditions allow I will be running some test with a known load.in my NEF single shot. The boolit is the RD TLC 225-50-RF, lubed and checked weigh 53.2 grains, 6.0 grains of IMR 700X, WSR primer, cases R-P NOT WEIGHED. This load chronoed at 1896 FPS and shoots 1/2 to 3/4" groups at 50 yards.

Looking forward to better weather.

[Wolfer]

You think your bored. I have no heat in my reloading, casting shed and the temps here seem to like it around 0 a lot of nights. Wind has been blowing hard any time I get a chance to try and call up a coyote.
Theres nothing on TV, I've read all my books, I can't find my Linspeed to refinish all my stocks. I'm literally about to go stir crazy. Woody

[olereb]

You think your bored. I have no heat in my reloading, casting shed and the temps here seem to like it around 0 a lot of nights. Wind has been blowing hard any time I get a chance to try and call up a coyote.
Theres nothing on TV, I've read all my books, I can't find my Linspeed to refinish all my stocks. I'm literally about to go stir crazy. Woody

It's been in the 80's and sunny here the last few days,you should come back down for awhile.

[popper]

Interesting idea. I'm having trouble clambering 9mm, I think due to case(base) thickness. HS doesn't make a diff. So maybe wt will allow me to cull good/bad cases. Thinking 115 cases are diff. than 130 cases. Thanks.

[Bigslug]

Years ago, when Pop and I were heavily involved in Highpower Rifle competition, Precision Shooting Magazine ran an article that covered some pretty serious research on what percentage of change to case weight equated to a change in internal volume that would make the round think that it had a tenth of a grain more or less powder inside it.

I don't remember the details, but as a result, I segregated my .308 into batches that were all within 3 grains of each other. As nit-picky as we were with the loading techniques back then, I would guess the formula would have said 5 grains or less for a .308. Larger cases like the .45-70 will be less finicky about this - smaller ones like the .221 Fireball are notoriously fussy about it.

I've taken to firing my load workups over a chronograph and try to place my final load in the flat spots where velocity does not significantly change as the powder charge increases over 6 tenths or so. These are the plateaus in the pressure curve where those little variables mean less. If you're loading close to a peak, they'll cause more trouble.

[Wolfer]

It's been in the 80's and sunny here the last few days,you should come back down for awhile.
To make matters worse, now I'm out of ice cream!

80s is sounding pretty good to me right now!

[.22-10-45]

I've been waiting to try out a couple of early Lyman .32 wadcutter moulds since before the holidays! Just too darn cold! Re-reading books on Alaska/Klondike gold rush..Sourdough Sagas one of the best with diaries going back to early 1880's...whenever I get to feeling sorry about the snow & ice..I recall that a cast iron stove would be glowing red hot & just a few feet away frost would be a foot thick on cabin walls..or when a saucer of mercury left outside would freeze solid..best to stay inside!

[tygar]

Years ago, when Pop and I were heavily involved in Highpower Rifle competition, Precision Shooting Magazine ran an article that covered some pretty serious research on what percentage of change to case weight equated to a change in internal volume that would make the round think that it had a tenth of a grain more or less powder inside it.

I don't remember the details, but as a result, I segregated my .308 into batches that were all within 3 grains of each other. As nit-picky as we were with the loading techniques back then, I would guess the formula would have said 5 grains or less for a .308. Larger cases like the .45-70 will be less finicky about this - smaller ones like the .221 Fireball are notoriously fussy about it.

I've taken to firing my load workups over a chronograph and try to place my final load in the flat spots where velocity does not significantly change as the powder charge increases over 6 tenths or so. These are the plateaus in the pressure curve where those little variables mean less. If you're loading close to a peak, they'll cause more trouble.

Sorry but absolutely not. 5 grains difference in a 308 is Huge! .5 grain difference for weighing & separating brass from the same lot. Even for hunting loads I would use .5 but depends on distance for most.

The difference in pressure from different weight brass is significant. Pressure equals change.

[Love Life]

Case sorting is a bummer. I'll order a large batch and segregate until I have 100 cases all within 2 gr of each other in weight. Then I have been known to use plugs and sort by water weight...painful.

Then I check neck wall thickness, and turn only if absolutely necessary. Primer pocket uniforming and flash hole deburring are in there as well.

Then I shoot. Random, uncalled fliers and I segregate that piece of brass for sighter or coyote use.

Sort bullets by base to ogive and then by weight...sigh.

My goal is the least amount of vertical dispersion as possible. The chrono and shooting guide me in this. Then there is the concentricity guage which makes me want to throw it on the ground and stomp on it.

About the only way I see I can do better is to get a promethius II or an lab scale that can weigh down to the kernel.

The minutia all adds up into dropped shots or missed steel. Through out the process I keep telling myself "You only have to do it once."

However; shooting pays dividends. Hours can be spent at the bench doing case and load prep, but when you have your load, go shoot. Keep shooting.

[Wolfer]

Back when I was loading for 5 different 223s for prairie dog hunting I bought a 1000 WC cases from a guy in Nevada. To do load work up I weighed out 50 cases that were within 1 grain of each other. Off the top of the box it took 55 cases to get me 50. Sometime later I bought 1000 LC brass and did the same thing. It took 150 cases to get me 50.
This doesn't help answer the OPs question as I can't recall testing the test cases against the rest.
Needless to say I like WC brass. Woody

[southpaw]

I weighed some new 338 wm Winchester brass. I took the lightest one (231gr) one from the middle (234gr) and the heaviest (236gr). The prep work involved was flash hole deburring, trimming and sizing. Those shots landed inside of .750" at 100 yards. This is about what it shoots with weight sorted brass. I can't say that I won't weigh any of them again but I know I won't be very picky with them.

It mostly depends on what you are shooting them out of. Is it a factory rifle that you mostly use for hunting or is it a custom gun that you shoot out to 1000 yards?

I know I won't weigh any cases for my one 06 since I know it won't see light past 200 yards on a stretch. I will weigh my 308, 22-250 and 223 that I like to see how small of a group I can get.

To answer the op's question yes it will make a difference but will it be noticeable or worth the effort? That is for you to decide.

Jerry Jr.

[Garyshome]

I noticed that there were some 223/556 cases that were more full with powder then others, to the point I did not think it was safe to finish loading them [may compact the powder]. I didn't check the weight though, they are plinking loads anyhow. Most are military stuff.