Thread: Case weight variation powder capacity and significants on the target

Originally Posted by TeRei

Firstly throw those S&B cases as far away as you can. They are junk.*You would get better returns with annealing and improving neck geometry and tension for the best release. 2C.

Yes, think I will do that. They really are waaayyy heavier.

Originally Posted by Oldbloke

Yes, I could have used AS50N which is a fairly fine shotgun powder. But, honestly, I use AS2208 in the 223 I want to know how much AS2208 they hold, not water.

If I had a container used to store biscuits and I wanted to know it's capacity, would I use water. Nope that would be useless, because of the shape and size of the biscuits. Because I need to know how many biscuits it holds. I understand it's different but, really!

True but depending on how your biscuits pack into the tin there could be between 26 and 50 percent empty space between them. Same with firewood if you have to buy it heaven forbid it's sold as a thrown meter pack it properly and you're lucky to get over half that. Same with powder. If you were to repeat your results several times for each case I suspect you will get a range of results that measure usable capacity, but the only true measure of the cases capacity is to use liquid.

Video from MDT. Maybe a bit simplistic and not a large enough sample size to satisfy some on here but gives food for thought on another ammo aspect that some individuals may get too hung up about. Brings back memories of clipping ends off .303 fmj ammo back in the day, worked well enough at short/medium range. Something to think about. Have at it.
https://youtu.be/svzsT3SYFXM?si=b1Y0eCoUUM5gbv2d

Originally Posted by Oldbloke

Yes, think I will do that. They really are waaayyy heavier.

Yep, done. Only 40.

OCD kicked in today.
Weighed a few 30.06 cases and once again filled them with 2208. Giving them a few taps certainly settled the powder. Did two of each case brand. Very little variation in capacity in the two cases BTW.
Anyway this is the result. Interesting to say the least.

Regarding sako cases. They were weighed a few weeks ago and have since been loaded.

A lot more variation than i expected.
I have abt 100 winchester cases that im currently using.
But last year purchased the 100 FC cases.
Unsure I can use them now.

I figure about 0.5gr variation in capacity will make little difference when hunting deer out to say,,130 yards, accuracy wise.

Comments.

Don't over think it. Go kill stuff.
Extreme spread doesn't change accuracy FA inside 600 yards on most cartridges.
Piss in the Rabbit hole and and move on

Originally Posted by 6x47

That is a well known difference with older NRA shooters. Commercial Win brass had a much higher capacity than mil brass. Using the same warm load from a Win case in the mil brass would produce much higher pressure. It wasn't subtle.

As John said above, slight differences are often imperceptible on game targets out to 300yds but count for a lot past 600yds.

Greetings,
In the early 1980's AAL gave me a batch of mostly LC81 cases that were giving him fits. They were hard to size and the crimp was hard to remove compared to the cases he had been using. The LC81 cases weighed around 20 grains more than the WW Super cases I was using, a bit over 2 grains of powder. I have never done a head to head chronograph comparison for velocity but might one day. As far as mixing different headstamp or even batches this is something I don't do if I can avoid it. Why would you?
GPM.

OCD again today as cold weather.

Among other things I compared Win and FC cases using GRT. No other changes. (Same bullet, pwdr and load) As you can see 59 fps difference. Very mild load tho. I thought it would be more.

I've realised because I have two 30.06s with different loads/bullets (and changing a load probably next year) I'll use Win cases for one rifle and FC for the other when I work up a new load.

Perhaps will carry out the same exercise for the 223.

60 fps would not be noticed on a target. I get this variation in loads using the same brand of cases.

Greetings,
Scratching through my records I found an approximate comparison.
Load 1 loaded 3/03/1991 and fired about that time. 150 grain Norma projectile, Norma case, 46 grains IMR4064, W120 primer, 22 inch barrel. Velocity 2,800 fps.
Load 2 loaded 24/10/2011 and fired 09/2020. 150 Rem corelokt, 45 grains IMR 4064 same lot as above, WLR primer, 20 inch barrel. Velocity 2,750 fps.
The chronograph was the same 35P initially running an eight foot screen spacing and later four feet. The 2 inches difference in barrel (the same barrel shortened) would account for around 50 fps so the Federal case which weighs about 183 grains and the Norma 165 grains would account for the remaining 50 fps.
This is a rough comparison but about what I expected. I have loaded some additional rounds which I will report on once I have shot them.
GPM.

Originally Posted by Oldbloke

OCD again today as cold weather.

Among other things I compared Win and FC cases using GRT. No other changes. (Same bullet, pwdr and load) As you can see 59 fps difference. Very mild load tho. I thought it would be more.

I've realised because I have two 30.06s with different loads/bullets (and changing a load probably next year) I'll use Win cases for one rifle and FC for the other when I work up a new load.

Perhaps will carry out the same exercise for the 223.

Pretty much in line with my results.
GPM.

Here is the 223 results. I had to weigh water capacity of some cases for GRT to give me the results.

Here id an interesting thread about this case capacity question.
https://thefiringline.com/forums/sho...d.php?t=595560

Originally Posted by Woody

Here id an interesting thread about this case capacity question.
https://thefiringline.com/forums/sho...d.php?t=595560

That was a good read, but now my head is swimming
So after getting through to the end of that he was testing for the Extreme spread of his fired cases dimensions? Not actual differences in velocity from different cases. Or have I read that wrong @Woody ?
It seemed at the onset thats what he was going for but in the end it became about case capacity only.

I find some of these US posts filled with detail that blurrs the original thought process.
Of note though I do use 55.5 grains capacity when using GRT for my load work.

Yes, it is a bot of a ramble by a bunch of armchair boys bit they admit to that fact. The best info there was the sd of case weights by brand. My own comparisons between win, lapua fed rem show vsriences from 160-190+ by brand and it is syandard practise to reduce loads by 1.5-2 grains if using military or other heavy brass like fed or lapua. The other elephant in the room is the changes over time within brands. Thete are significant differences in case weight in norma, win and others since a decade ago. One cannot assume older brass is same as new brass, even with same headstamp. I weigh and label all mine for that reason. The significance is greater toward max loads, just as seating depth and bullet are.