Overall case length

[thumbs]

Just wondering what effect case length has? The reason I ask is I am trying to make all the cases the same size and am wondering how short is to short? I know to long is a problem but if the OAL or the completed cartridge is within spec is the length of the brass that awful important as long as they are the same?

thanks

 

[Titegroups]

Simply put for revolver ammo case length is really only a factor in consistent crimps, for autoloader ammo the cases also headspace off the case length so thats an additional factor. Rifles are a different story. Most practical handgun reloaders don't concern themselves with case lengths unless you're having some type of issue.

 

[AlwaysUp56]

I am getting back into reloading pistol ammo after having been out for quite a spell, but in brushing up on methodology and all I bought Lyman pistol and revolver handbook, 3rd edition. Anyway from what I read it is best to trim if case exceeds the "trim to length". Trimming further? Why? if you find an especially short case, crush th mouth with pliers and toss into your scrap brass bin. The amount of a given charge of powder in a short case might result in unexpected pressures very different from data tables. Reloading is like following a recipe, in the sense that you should always follow load data as precisely as possible from one cartridge to the next when reloading to get reliably repeatable results.

 

[thumbs]

Just wondered. I'm not being ridicules about it. I just wanted to cut all the cases to the same length. Some of the cases are pretty long. I am cuttin them to the average. I "think" that if the the OAL of the round were in spec then the pressure should be fine. I say "I think" unless someone can explain otherwise. Ya never know there maybe a reason.
I know to long is a problem.

 

[Titegroups]

What caliber, what gun? Where did the cases come from and the history? How long? More info. Generally not an problem though.

 

[thumbs]

S&W Sport .223. These are American Eagle AR .223 ammo bought at Walmart. I fired them once. After firing they were running 1.135 or so. (I think) I do not have the book with me but "I think" the Lee book says 1.17??. Most of my casings are under 1.140. I wanted to cut them reasonably the same so I allowed them to go to 1.140 before I cut them and cut the gauge to 1.140.

The problem came in when I changed my method of cutting the cases. Anyway I cut a bunch down to 1.133. Not sure the Sport cares but I found the difference is a bit much when loading. I set the dies for the 1.140 size cases. The major problem came when dumpin the powder. I am using the Lee powder measure on the press. Using the 1.140 length it works fine. I get the full amount of powder being dropped. When I try the 1.133 the disk does not extend out enough to drop a full charge. The case is to short to activate the powder drop properly. I could recalibrate the thing but that just throws another problem into the mess. I may load them anyway by manually moving the disks to dump the powder but I would like my casings to be all the same or close. I think the rifle will handle the 1.133 case but it's more trouble than it's worth to load.

 

[2hawk]

thumbs, case length is pretty important on rifle ammo. 50K psi is alot to be dealing with, especially when it's only a few inches from your face. Don't be guessing, get some good info and stop experimenting.
I found this in a couple of seconds of web searching, so not having a book is no excuse:

http://www.varmintxt.webs.com/images/bullets/223rem.png

The numbers you're using are way off. The trim-to length I use for .223 is 1.75", and that diagram shows the spec at 1.7598". I think you should stop loading and start checking your dimensions and methods if you value your eyes and fingers. No slam, but I'd hate to see your next post being about "my rifle blew up." Take care.

 

[Gamer]

How short is to short, I guess each caliber, rifle or pistol case could be different but I looked into how short was to short for 45 Colt cases a while back. For example, my Hornady manual lists max case length as 1.285 and case trim to length of 1.275. I looked into the SAMMI spec and it shows case length as (-.020/ + none). So, I took it as no longer than 1.285, no shorter than 1.265.

I suppose you could trim your cases to something other than 1.275, but I use this number because I assume the OAL given for specifc round is based upon the trim lenght specificied.

 

[thumbs]

thumbs, case length is pretty important on rifle ammo. 50K psi is alot to be dealing with, especially when it's only a few inches from your face. Don't be guessing, get some good info and stop experimenting.
I found this in a couple of seconds of web searching, so not having a book is no excuse:

http://www.varmintxt.webs.com/images/bullets/223rem.png

The numbers you're using are way off. The trim-to length I use for .223 is 1.75", and that diagram shows the spec at 1.7598". I think you should stop loading and start checking your dimensions and methods if you value your eyes and fingers. No slam, but I'd hate to see your next post being about "my rifle blew up." Take care.

No slam taken. I think I meant 1.740. That's why I kinda hate to post numbers, I sure don't want anyone to match them.

Yeah the reason for the 1.740 is the factory (American Eagle) run about 1.735. I "think" the 1.7598 is the case limit. I was just trying to stay close to the factory length knowing I could go as long as 1.7598. The reason for the original question was if the case length expands a few thousands would it really make a difference? My thinking was if the factory length is 1.735 and the length limit is 1.7598 then anywhere in between should be safe. The question would then be, if within he limits, how does case length effect accuracy?

The OAL for the cartridge is the same so the cavity for the powder is the same no matter what case length I am using. Really the only variable is the length of the neck itself.

I am always open to constructive criticism. And your concern for my safety is appreciated. Your right ya gotta be careful with this stuff. I don't "think" I am out of bounds with my loads. If I am sound off. I always thought the problem with case length came when it was to long. Remember my powder cavity is the same. The bullet is in the same place as factory in the chamber.

I can be wrong but I "think" the diagram uses max lengths. I can be wrong here. I know the factory lengths are shorter in both case length and OAL. I was just trying to say close to factory length and be able to cut them to the same size. No way will these cases every get to 1.7598. Well not for their useful life anyway. At least I would dough they would expand that much. I know they load well.

 

[AlwaysUp56]

Simply put...set your calipers to the listed case length of a given cartridge and lock it down. Each fired or even unfired factory case should be measured for excessive case length and trimmed to the listed length, PERIOD. If you do find a short case, trash it! This is not a passtime for those for which DETAILS do not matter. Incidentally, this is also a good time to remind that after case trimming, you should always deburr the inside and outside of each casemouth. Good time to inspect for any casemouth splitting or other condition that would render the case not suitable to reload.

 

[2hawk]

thumbs, I'm glad you're asking the questions. And I need to make a correction, I use 1.72 as a trim to length. Been awhile, I had to check.

So if you're at 1.733, I wouldn't see any problem as far as shooting them goes. They will stretch a little each time anyway, so no need to trash them on that basis. But, if they are anywhere in the range you mentioned, I don't even see how they could work.

My thinking on the short cases is, if they can cause a problem when you're reloading, do you really want to see if they're going to be a problem when you shoot them? You are right as far as I can figure, short is better than long, but even that has got to have a limit. Case pressure will be the same with the same OAL, but I would be concerned about the neck tension, especially if you are using a boat-tailed bullet. Worst case scenario I can think of would be that you chamber a round, have a FTF or need to eject it, and stick the bullet in the bore. Usually that would easily be caught due to all the powder in the action, but if not caught by a fan of the forward assist, there could be a BIG problem.

I don't know how many cases you have that are short, but I'd say scrap them and just keep things simple. Trying to fix things with work-arounds just isn't worth the trouble a lot of times. Stay Safe!

 

[thumbs]

Simply put...set your calipers to the listed case length of a given cartridge and lock it down. Each fired or even unfired factory case should be measured for excessive case length and trimmed to the listed length, PERIOD. If you do find a short case, trash it! This is not a passtime for those for which DETAILS do not matter. Incidentally, this is also a good time to remind that after case trimming, you should always deburr the inside and outside of each casemouth. Good time to inspect for any casemouth splitting or other condition that would render the case not suitable to reload.

I understand what your saying but the problem is I will have to throw away every brass case I have after firing them once. None of them are 1.7598. I dough that they will ever be that length. The factory length of the case is 1.735. The question is what is to short? I don't believe that the factory made all their cases to short. I know of no way to expand the neck from 1.735 to 1.7598. The overall length of the cartridge is also shorter than the book spec. I am sure the factory lengths are safe. I won't go below them.

I was just wondering if anyone knew the answer to how short is to short and what effect case length has on accuracy if any?

 

[thumbs]

thumbs, I'm glad you're asking the questions. And I need to make a correction, I use 1.72 as a trim to length. Been awhile, I had to check.

So if you're at 1.733, I wouldn't see any problem as far as shooting them goes. They will stretch a little each time anyway, so no need to trash them on that basis. But, if they are anywhere in the range you mentioned, I don't even see how they could work.

My thinking on the short cases is, if they can cause a problem when you're reloading, do you really want to see if they're going to be a problem when you shoot them? You are right as far as I can figure, short is better than long, but even that has got to have a limit. Case pressure will be the same with the same OAL, but I would be concerned about the neck tension, especially if you are using a boat-tailed bullet. Worst case scenario I can think of would be that you chamber a round, have a FTF or need to eject it, and stick the bullet in the bore. Usually that would easily be caught due to all the powder in the action, but if not caught by a fan of the forward assist, there could be a BIG problem.

I don't know how many cases you have that are short, but I'd say scrap them and just keep things simple. Trying to fix things with work-arounds just isn't worth the trouble a lot of times. Stay Safe!

Ok it looks like your shorter than I am. I'm at 1.740 as my max. Some didn't expand so they run around the 1.735 factory length. I have had no problems with ftf or fte with factory or handloads.

Yeah I'm trashing the short cases. I was trying a new way to trim and "assumed". Anyway there weren't that many anyway but the question came to mind. I guess it would be nice if the specs gave you a range of go no go. I know people work up loads using different case lengths, OAL's and powder changes to suit their particular rifles. I can't remember ever having a factory length of 1.7598.

 

[MichiganScott]

Simply put...set your calipers to the listed case length of a given cartridge and lock it down. Each fired or even unfired factory case should be measured for excessive case length and trimmed to the listed length, PERIOD. If you do find a short case, trash it! This is not a passtime for those for which DETAILS do not matter. Incidentally, this is also a good time to remind that after case trimming, you should always deburr the inside and outside of each casemouth. Good time to inspect for any casemouth splitting or other condition that would render the case not suitable to reload.

I disagree. Trim to recommended length which is 1.750" or 0.010" less than max. Any cases that are too short will hit recommended trim length after two or three loads.

FWIW, RCBS recommends that you trim your brass to 0.010" less than usual when using their X-Dies, in this instance 1.740". 1.735" is short, but no big deal.

 

[Titegroups]

Simply put...set your calipers to the listed case length of a given cartridge and lock it down. Each fired or even unfired factory case should be measured for excessive case length and trimmed to the listed length, PERIOD. If you do find a short case, trash it! This is not a passtime for those for which DETAILS do not matter. Incidentally, this is also a good time to remind that after case trimming, you should always deburr the inside and outside of each casemouth. Good time to inspect for any casemouth splitting or other condition that would render the case not suitable to reload.

Be careful of your assumptions, as with any task experience teaches you whats practical. You will find few handgun loaders who check empty case lengths, especially every shot. Rifle reloading requires more attention to details, the vast majority of threads here refer to handgun reloading.

 

[krallstar]

Are you sizing these before you measure. The expander ball will pull alittle when sizing and stretch the neck some. Most like to run their .223 brass @ 1.750 no shorter than 1.740 but not more than 1.760.

Yeah the reason for the 1.740 is the factory (American Eagle) run about 1.735. I "think" the 1.7598 is the case limit. I was just trying to stay close to the factory length knowing I could go as long as 1.7598. The reason for the original question was if the case length expands a few thousands would it really make a difference? My thinking was if the factory length is 1.735 and the length limit is 1.7598 then anywhere in between should be safe. The question would then be, if within he limits, how does case length effect accuracy? Neck length does have effect on accuracy. longer neck means more neck tention. If you are shooting bullets with a cannalure and you crimp, 1.740 is to short to hit it. At 1.750 and you should be in the middle of this cannalure.

 

[bevenue]

Are you measuring the OAL before or after you resize the brass?

 

[thumbs]

Are you measuring the OAL before or after you resize the brass?

I measure after resizing.