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anotherted
12-10-2006, 10:00 AM
Hey there,

Ive been sizing my brass with a LE Wilson trimmer and measuring the case length with a Frankford Arsenal digital caliper. From my reading, it looks like the length of the resized case should be @ 2.005" (.308 cal.). Ive messed with the trimmer to get it as accurate as i can but when i measure the case, i get different sizes none the less. For example, i get 2.005" for one, then trim the next case and get 2.0035", then another @ 2.0045", then another @ 2.0065", etc. I realize that i am dealing in thousandths of an inch, but how precise do i need to be in getting the length 100% on the nose @ 2.005"?

Also, when i deburr will this reduce the length of the case?

Thanks,

Ted

LCAZES
12-10-2006, 10:47 AM
You are now within measurement error for most calipers. If I recall "2.005 is the SAAMI MAX OA case length for .308, correct?

ivanimal
12-10-2006, 11:05 AM
There is a minimum, which has to do with the grip on a bullet and aid in obteration, and a maximum, which has to do with pressure increase. As long as you stay within those limits you are fine. The average sportsman falls into this category bench rest shooters on the other hand are more precise in their needs for uniformity. The only reason I have my cases really close would be when using a crimp, or reloading the 45 ACP which headspaces on the case mouth. When using a crimp die if the cases were all different sizes you would have to adjust for each one. For 45 ACP you would get a lot os misfires or light primer strikes. The worst case scenario is when you do not trim and load max, the increase in pressure could be dangerous. I always measure for max. Not usually for Min unless I have to trim.

Vepr62
12-10-2006, 11:28 AM
Use LEE hand trimer. It consists of a cutter attached to a guage pin, and a shell holder. You affix your shell to a shell holder, insert the pin guage inside and through the primer hole, few turns until your pin hits the bottom of a shell holder and you are done. Same lenght EVERY time.
Vasiliy

anotherted
12-10-2006, 1:16 PM
There is a minimum, which has to do with the grip on a bullet and aid in obteration, and a maximum, which has to do with pressure increase. As long as you stay within those limits you are fine.

So what is the minimum and maximum?

Vepr62
12-10-2006, 11:10 PM
Actually standard lenght for .308 Winchester is 2.015, not 2.005, and my cutter does exactly that. I have found that Hornady once fired brass does not need treeming. Remington brass is not very consistent in lenght, some cases are ok, and some need treeming. The longest bras is Federal. I treem all federal once fired brass. If i bring brass from the range, I resize whole case, and brass from my rifle, I resize the neck only. Deburring won't change case lenght. Hope this helps.

Vasiliy

anotherted
12-11-2006, 8:14 AM
I would simply like to know what the minimum and maximum case lengths are for the .308., and if the fluctuations in my case measurements are ok.

ocabj
12-11-2006, 8:41 AM
2.005 is the minimum. 2.015 is the maximum. This is from all manuals I own and have seen.

I trim to 2.007. I don't trim to the bare minimum. I like to trim to slightly above. Plus, I load ammo in batches, thus I process brass in batches. For .308 specifically, I use Lapua from 100ct boxes. I keep brass from each box together, separated from the brass from other boxes. I trim all the brass in each box/batch to the same length. In this case, around 2.007. As long as all the brass in that specific batch is the same length, that is my main concern as far as case length.

You can always trim to 2.015, but the key to accuracy is consistency. In order for you to be consistent while trimming to a longer length, all the brass in your batch needs to be growing to or above 2.015 in order for you to trim it to the same length. That's why you trim to or close to the minimum.

anotherted
12-11-2006, 9:01 AM
Perfect, thats exactly the information ive been looking for. Thanks ocabj.

ocabj
12-11-2006, 9:33 AM
Perfect, thats exactly the information ive been looking for. Thanks ocabj.

No problemo.

Oh, in response to your question about deburing the case neck, it doesn't 'trim' the case length. What you may notice is that when you trim brass (and quite a bit is trimmed off since the brass is long), the neck face becomes flat and has brass bunched up around the outside diameter. You want to debur the inside and outside diameter before you measure the case length so that excess brass in the inside/outside doesn't affect your measurement.

Of course, it's possible to 'trim' brass with a deburring tool if you chuck it into some kind of power tool (cordless drill, drill press) and really go at it for too long. But by hand, it's pretty hard to shorten brass length with a hand deburring tool.

50ae
12-11-2006, 10:42 AM
I must say, I've never trimmed my 45's and haven't had a problem but now you've made me paranoid so I'll have to go measure a representative sample of my cases. Now, being that I have about 30k of spent cases that means I'll have to do a lot of measuring and being that I'll probably find differences I'll end up finally buying a trimmer which means I'm going to end up in a fight with the wife over money so therefore, thanks for starting a fight between my wife and I;) BTW, my guess is that I'll end up with one of those Dillon trimmers that mount on my press, good thing I worked out in CA the last two months and took my big CA money back to TX:p

There is a minimum, which has to do with the grip on a bullet and aid in obteration, and a maximum, which has to do with pressure increase. As long as you stay within those limits you are fine. The average sportsman falls into this category bench rest shooters on the other hand are more precise in their needs for uniformity. The only reason I have my cases really close would be when using a crimp, or reloading the 45 ACP which headspaces on the case mouth. When using a crimp die if the cases were all different sizes you would have to adjust for each one. For 45 ACP you would get a lot os misfires or light primer strikes. The worst case scenario is when you do not trim and load max, the increase in pressure could be dangerous. I always measure for max. Not usually for Min unless I have to trim.

ivanimal
12-11-2006, 10:57 AM
Thank you ocabj for getting the info out so fast!

The subsonic cases such as the 9MM 45ACP 38 special................do not create enough heat aka pressure to cause brass flow. Brass flow is the reason we must trim. I have never had to trim 45 ACP but do measure anyway. I have a gauge that makes it easy, too easy to not do it. I do this while examining the cases for flaws.

http://img.photobucket.com/albums/v631/ivanimal/f81507.jpg

thmpr
12-11-2006, 11:50 AM
For the 223 and 6.8, trimming is a must. As long it is within the max and min specs, no trimming is required. But I normally trim all my cases to min specs due to metal expansion after firning and sizing. The Giraud trimmer is a must when high volume of trimming is required.
For the 6.5 Grendel, no trimming required after 4 re-loads. Maybe due to the hardness criteria.

xrMike
12-11-2006, 12:39 PM
I must say, I've never trimmed my 45's and haven't had a problem but now you've made me paranoid so I'll have to go measure a representative sample of my cases.Don't bother! Nobody trims .45ACP (or any other straight-walled brass). The only brass that grows longer from shooting are the "necked" calibers.

.45ACP actually shrinks a little, the more you shoot it.

50ae
12-11-2006, 1:20 PM
OK Animal, where did you get that guage? I must have one!!!!

I didn't think anyone trimmed 45's but I just wanted to be sure. I have loaded well over 200k 45's on my Dillon and never had a problem but it is always good to learn new tricks.

sargenv
12-11-2006, 1:59 PM
I disagree completely about straight wall pistol cartridges. 10 mm and 357 magnum both stretch if you load magnum loads or if you load them several times. I have a bucket of about 200 or so 357 magnum cases, and about 250 10 mm brass that are all about .002-.005 too long to chamber. Despite having a moon clip on the 10 mm, if they are over long, they will not chamber well in the 610 revolver. I don't know how they perform in a semi since I have yet to own a 10 mm semi.

Vince

xrMike
12-11-2006, 3:08 PM
I disagree completely about straight wall pistol cartridges. 10 mm and 357 magnum both stretch if you load magnum loads or if you load them several times.Interesting, I heard (or read? can't remember...) differently. You learn something new every day I guess. Don't think .45ACP stretches though, if anything the opposite.

NRAhighpowershooter
12-11-2006, 4:18 PM
I have found that I need to trimm on occasion my 357 brass and my 45LC and ALWAYS 44mag brass..... and have yet to trim ANY of my 9mm and 45acp brass.. and some of my 45acp brass has been reloaded over 20 times and has been in use since '85

dw1784
12-11-2006, 6:15 PM
OK Animal, where did you get that guage? I must have one!!!!


Lyman makes one:
http://www.natchezss.com/product.cfm?contentID=productDetail&prodID=LY7832215&CFID=1377938&CFTOKEN=57355261

xrMike
12-11-2006, 6:33 PM
Yeah, my mistake on the trimming comment. Just checked my Lee reloading manual and he states that hot or magnum pistol loads may sometimes require trimming. But generally, pistol brass does not.

ivanimal
12-11-2006, 11:09 PM
Any load over 1000 FPS is my que to look at trimming. The 45-70 is a straight walled case that usually needs a trim.

ebay is your friend.

http://cgi.ebay.com/Max-case-length-gauge-many-calibers-OLD_W0QQitemZ250057962925QQihZ015QQcategoryZ71117Q QrdZ1QQcmdZViewItem?hash=item250057962925
http://cgi.ebay.com/Rifle-Max-case-length-gauge-270-45-acp-reloading-press_W0QQitemZ180061347020QQihZ008QQcategoryZ7112 0QQrdZ1QQcmdZViewItem?hash=item180061347020
http://cgi.ebay.com/McKILLEN-HEYER-MAXIMUM-CASE-LENGTH-GAUGE-RELOADING_W0QQitemZ260060189412QQihZ016QQcategoryZ 71117QQrdZ1QQcmdZViewItem?hash=item260060189412

anotherted
12-11-2006, 11:53 PM
After i used the deburring tool i was getting consistent 2.007" measurements. I also went out and bought a vice. This helps out with speeding things up.

Thanks,

Ted