New brass then after first shot

[misskimo]

Hey. Been reloading for about 6 months. Been having a blast. I bought the lees 50th Anv kit for for my collection of rifles. 223, SKS, 22-250, 243, 270, 30-30 , 308, 30-06 , 338 win mag and 300 ultra mag , winter is here so I can't shoot to test out my test loads. But my question is. New brass for each of my cal will run low and then I will have to reload used brass. You see. I did all these load groups to find what works best with my gun, with new brass, After the new is gone , I will have too find the magic load again huh?
Tonight I loaded the last of my new 308 brass , test loads with a different bullet . So for kicks and giggles, I dug in my box of shot shot once brass and grabbed a 308 shell. Filled it slapped full of powder. Then filled up a new brass to the top packing it good. Measured the shell and powder and man. 1 gr difference, I bet my pet load with new brass will fly out the end of the barrel with used brass huh?
What do y'all do



Tony

[roklok]

That is a very unscientific method of measuring capacity, and I can not imagine ten grains of powder capacity difference between new brass and once fired brass (unless it was fireformed brass in an improved chamber, and even then 10 grains is a stretch). A better aproach is to weigh the amount of water each case can hold.

That being said, I normally do not use brand new brass for serious purposes, reserving it for range use and practice. I work up pet loads and hunt with brass that has been fired at least once.

[hogcowboy]

I don't see what the big deal is. I've never seen that much difference between new brass and once fired unless you are look for serious long range shooting. Put your pet load in both. Just use the new stuff for target shooting.

[Myke_Hart]

Are you sure you did not compare a 30-06 case to your new 308 cases?
Doing that should give you somewhere around a 10 grain difference.

Then again if you did not subtract the weight of the brass it might be possible to be that far off.

Your measurements will also be skewed if one peice of brass was fired out of your gun and the other out of someone elses. The same thing happens if one peice is unfired and the other is fired. If this is the case...Full length size the new and old brass being careful to keep the spent primer. Then put an old spent primer back in the cases. (this will hold the water in)

Weigh the clean and empty cases...new brass and old brass... Write that down.

Fill them both with water and tap out the bubbles and make sure they are full.

Weigh them full of water...write that down.

Subtract the empty weight from the full weight. (the result is your case capacity)

There should not be a huge difference between the capacity of the old and new peices of brass if they are both commercial 308.

Nato 308/7.62x51 will give you a different capacity than commercial as well.

[DiscoRacing]

If you full length size it and trim... it will be the same as new.

[wncchester]

"After the new is gone , I will have too find the magic load again huh?"

No.

[Unclenick]

Originally Posted by misskimo

After the new is gone , I will have too find the magic load again huh?

Not at all. Here's the thing:

Pressure depends on how much volume the powder is burning in. In loads that fire at approximately 30,000 psi and up, the case expands until it sticks to the chamber wall and the head stretches back and touches the breech face all before the powder has got very far in its burning curve and before the bullet bullet has moved very far down the bore. The result is that the peak pressure depends on the volume the case expands to in the chamber, not on the volume the case has when it is inserted into the chamber. So, the chamber size is what is determining peak pressure and barrel time, not the volume of the new or resized cases.

[4runnerman]

"After the new is gone , I will have too find the magic load again huh?"

No. Deprime,resize,load and go TaDa,all done.. Check case length if your serious

[mehavey]

I dug in my box of shot shot-once brass and grabbed a 308 shell. Filled it slapped full of powder. Then filled up a new brass [case] to the top packing it good... 10 gr difference.

I too, have a [real] problem envisioning a 10 grain diffference between two cases of the same 308 Win cartridge.

Please repeat this comparison using water (full case -minus- empty case) and tell us the difference in net water weights. Also tell us the brass manufacturer(s).

[FrankenMauser]

If you want to get back to near-original capacity, just Full-Length size the cases.

[medalguy]

10 GRAINS???? No way. I only put about 42 grains in 308 when loading and the powder is near the top of the case. No way could I ever get another 10 grains in there, not that I would want to.

I bet my pet load with new brass will fly out the end of the barrel with used brass huh?

You're not serious, are you? If so let me know which range you are planning on using. I'll stay away.

[misskimo]

Thanks y'all. I will deprime and resize it Then do some experimenting to find out my self

[4runnerman]

yes a error was made for sure here somewhere.The only way this could happen is if case length grew that much,which in that case would not matter because it would not fit in you gun any more 10 gns is a lot ogf powder

[700cdl]

Are you weighing one with a spent primer and the other with a new primer?
Is the once fired brass tumbled?
Is the once fired brass trimmed, reamed, and chamfered?
Are they both the same headstamp and from the same lot?
Once fired brass will often have a different volmetric size as it has been spread out in areas where it was once thicker and expanded to your guns chamber. Also, residue will adhear to the inside changing its volmetric size as well. There are a lot of possible variables between new and fired brass.

[700cdl]

Even if you FL size and trim it, it will still have different demensions than new brass. Once it has been fired it will stretch and thin out changing shoulder position as well.

[temmi]

""After the new is gone , I will have too find the magic load again huh?"

No. Deprime,resize,load and go TaDa,all done.. Check case length if your serious"



You Must check case length as a safety measure.

If the case is too long the neck can crimp the bullet and raise the pressure.

Do not exceed the maximum case length

[wncchester]

"After the new is gone , I will have too find the magic load again huh?"

But the question is about the need for further load development.

[misskimo]

Well yeh. And I recon I will load the used brass with my new brass loads and see. I just prep and resized about 60.
Also. My bad on the 10 g. Take away the 0. 1 g bigger after a shot. I would have thought they do get a tad bigger after its first shot is all which would mess with you pet load when new. My bad. Yall

[Cowboy_mo]

Misskmo..... you stated a 1 gr difference in your OP. I been going nuts wondering where this 10 (ten) gr difference came from.

Unless you are loading max or max plus (very dangerous) once fired cases and new cases should hold the same loads w/o problems. At least that has been my experience in the short time I have been reloading.

[roklok]

Cowboy Mo, read the post before yours.

[misskimo]

I wasn't loading it to the max. Like I said. For kicks and giggles I compared a new brass with one that was shot by using a full load of powder and weigh. Then dump it back in the powder can afterward, Sorry. My bad

[roklok]

The main reason I do not use brand new brass for hunting has to do with its reliablity more than accuracy issues. My favorite cartridge for big game hunting is the .35 Whelen. I have three rifles chambered for the Whelen. Two of them (Ruger 77 and Ruger #1) will not fire reliably with brand new brass, as the shoulder is smaller than fired brass. Both have exhibited numerous misfires with brand new brass, as the case shoulder does not fill the chamber correctly, and cartridge is able to move away from the firing pin. Using resized fired brass, the shoulder is much more defined, and have never had a misfire using them. My Rem 700 fires both equally well, but I figure why chance it, if the other two rifles prove fired brass to be more reliable.

I have not noticed this with any of my other rifles in other chamberings, but my uncle has a Ruger 77 in 30-06 that acts the same as my Ruger 35 Whelens. For it to be reliable, brass has to be fired previously.

[Qtiphky]

You don't need to do anything other than trim the used cases and neck size. They were fired in your gun and you are developing loads for your gun. They are now fireformed to your chamber and after trimming, you will only need to neck size them and they will fit perfectly to your gun.

They will now be more accurate than when you tested them with the new brass, so yes, they may change, but I would say for the better. Many of us do and have done this. I bought commercial for my 308 and used them up. Then, because they were fireformed to my chamber, I trimmed and neck sized them with the loads that I wanted to test. Guess what, they became more accurate and I had no problems at all. I have done this with 2 308's, 300 wsm, 270, 22-250, and 204 Ruger. They have become very accurate guns, the brass lasts longer and my reloading costs have gone way down because I am re-using the brass. That is where the savings come in.

[wncchester]

(neck sized)... "They will now be more accurate than when you tested them with the new brass, so yes, they may change, but I would say for the better."

Well, that's common hunting campfire 'wisdom' but it rarely works out that way on targets. FL sizing is quite often as accurate, or more so, than "fireformed-necked" ammo and the feeding is flawless. Even when there is an advantage to neck sizing in a factory rifle it's tiny. And there is no way in this world anyone can predict how any given change may affect accuracy.

[Doodlebugger45]

Thanks wncchester. It's reassuring to hear someone else validate what my own observations show me. I have taken to partial full length sizing, mainly in the interest of prolonging brass life. I tried neck sizing only when I first started loading for rifle cartridges (I started with pistol cartridges because it seemed simpler). I didn't like the fact that after neck sizing once (those "usually" chambered fairly well most of the time) by the second or third time, they were not chambering very consistentnly at all. And I do like consistency. So I finally figured out how to measure my headspace and then use a feeler gauge to set my dies so that I was only bumping the shoulder back about 0.002" As stated, it was mainly for consistency and also to prolong brass life. However, I had read where folks claimed that neck sizing only or partial full length sizing would improve accuracy. Either it didn't improve the accuracy or else I'm just not a good enough shot to tell the difference. Accuracy is fine either way, I just couldn't tell any difference.

Another thing I do is track my brass pretty closely. I mean that when I buy 100 new cases, I don't go out and load up all the new ones until I run out and THEN start reloading them. Typically, I will have maybe 2 or 3 different powders that I want to experiment with using one particular bullet. For a given powder, I might load up 20-25 rounds with different weights of powder and see what works best. As I see some favorable results grouping around a certain weight, I use those same 20-25 cases trying to dial in the perfect combo of powder and seating depth. I will have a different set of 20-25 cases reserved for experiments with a different powder. As much as possible, I try to make sure that each set of 20-25 cases are reasonably close in weight to one another. I don't get compulsive about it, but I try to eliminate as many variables as possible.

Naturally, I always keep the cases segregated by manufacturer. That's an even bigger variable than case weight alone I think. For a given caliber most brass made by a given manufacturer is reasonably close in weight. I typically just segregate mine into "heavy" or "light" weights if the spread isn't too much. For a couple calibers, I have more cases so I can divide them up into 3 weight classes. It does mean though that when buying new brass, you kinda have to stick to one brand of brass for a given caliber. Otherwise you get a very large assortment of brands and weights. Although, sometimes that's not bad either. I have a couple of 7 MM mags I load for. They have very different headspace requirements. So, to aid in keeping brass separated, one rifle gets Remington brass and the other rifle gets Winchester brass. So all my 7 mm Winchester brass gets the sizing die set one way and the Remington brass has a different setting.

The one exception I made to that practice is for my .243. I had about 120 pieces of Hornady brass from factory ammo I had bought and shot. When I started reloading, I couldn't find Hornady brass, so I bought Winchester brass. I still use both, but I have to keep them separated to ensure racial purity.

I think the OP will quickly discover that having to "resort" to re-using brass is not a compromise at all. It is the very essence of reloading and the results will actually be better and more consistent loads than just using new brass.