The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Reply
 
Thread Tools Search this Thread
Old February 18, 2010, 01:51 PM   #1
ScottRiqui
Senior Member
 
Join Date: January 27, 2010
Location: Norfolk, VA
Posts: 2,905
How often do you trim .223 brass?

I'm about to start reloading .223 (the dies & other stuff should be on my doorstep when I get home today.) Last night while I was tumbling the brass, I measured a few dozen cases to see where they fell compared to the recommended length.

Both my Lee and Speer manuals list the case length specification as 1.76". All of the cases I measured fell between 1.745" and 1.755", so they don't appear to need trimmed yet. I realize that they may stretch a little bit once they're full-length sized, but do you find that you have to trim .223 cases after each firing, or even after every other firing?

Thanks,
Scott
ScottRiqui is offline  
Old February 18, 2010, 01:57 PM   #2
Hey_Allen
Member
 
Join Date: October 14, 2008
Location: NW Washington
Posts: 39
It's not likely that you'll find oer length cases before sizing, unless you're processing new brass that you just pulled out of a bag.

I plan on having to at least check length on every reloading cycle, and likely trimming every cycle.

Some of the reports on the RCBS X-dies I've read seemed to be saying that they cut down on how much the case is stretched during sizing, but I haven't had the chance to play with them, so I couldn't say how much that cuts down on the trimming required.
Hey_Allen is offline  
Old February 18, 2010, 02:09 PM   #3
rjrivero
Senior Member
 
Join Date: November 17, 2008
Location: NW Ohio
Posts: 1,399
The key to success is consistency. I trim all the .223 brass to 1.750 every time for semi autos. I have a log for specific length for each bolt gun.
rjrivero is offline  
Old February 18, 2010, 02:17 PM   #4
DiscoRacing
Senior Member
 
Join Date: December 19, 2008
Location: milton, wv
Posts: 3,640
since im actually way too worried...and have free time.... i trim mine after each sizing...and its for a bolt gun no less.
DiscoRacing is offline  
Old February 18, 2010, 02:20 PM   #5
ScottRiqui
Senior Member
 
Join Date: January 27, 2010
Location: Norfolk, VA
Posts: 2,905
Thanks all for the replies.

rj and Disco - I agree wholeheartedly about the benefit of running every case through the trimmer each time for the sake of consistency, but do you generally find that you're actually removing brass each time, or do you mostly find that the cases are still in-spec?
ScottRiqui is offline  
Old February 18, 2010, 02:21 PM   #6
rdmallory
Senior Member
 
Join Date: February 10, 2009
Location: Deltona FL
Posts: 953
I have ran across some "cheep" ammo that was too long after one firing. I was told some of the over seas ammo you can get now is using "reconditioned" brass. So I would spot check all of it especially if it is range pickup.

Doug
rdmallory is offline  
Old February 18, 2010, 02:23 PM   #7
rjrivero
Senior Member
 
Join Date: November 17, 2008
Location: NW Ohio
Posts: 1,399
After I pick up "once fired" brass, it'll need a good trimming. However, I'll find that on the second or third reload, there isn't too much additional trimming. The 4th and 5th will have significantly more brass trim in the scrap bucket.

I use a Dillon Rapid Trim setup for the semi Auto brass. (i.e. BULK brass prep.)

I use an RCBS for any runs less than 50 or so pieces.
rjrivero is offline  
Old February 18, 2010, 02:25 PM   #8
DiscoRacing
Senior Member
 
Join Date: December 19, 2008
Location: milton, wv
Posts: 3,640
sometimes its not taking off any at all...and sometimes you can see some trimmings each time... using mixed headstamps makes a lot of difference...each brand seems to expand at different rates...dont take much of a difference to make a difference...that is why i just save the guesswork and trim each time.
DiscoRacing is offline  
Old February 18, 2010, 03:01 PM   #9
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,022
The SAAMI specification for .223 brass is 1.760" +0.000/-0.020. In other words, 1.740" to 1.760". Case trimming by manufacturers isn't very precise, so they generally aim for the middle point, 1.750" to have maximum available error. I see commercial trim length in new bulk brass run up and down around that number by several thousandths all the time. Many load manuals also recommend that midpoint target trim length. The fixed cut length Lee trimmers are set up to cut to that length. Before I got my Giraud trimmer I always trimmed my match .308 and .223 brass on an L.E. Wilson trimmer, which tool is consistent withing about two thousandths. So I trimmed back to minimum plus a couple thousandths, and got the a maximum number of reloads without retrimming that way.

A number of .308 gas gun match shooters just ignore the SAAMI minimum and trim to -0.030" or -0.040" from maximum. That way they never have to trim again, even without the X-die, before they toss the cases (usually after four loads or so in the gas guns). That doesn't seem to hurt them since they don't load short bullets that need as much grip as possible.

How much will cases grow? If depends on several factors: brass hardness, load history, peak pressure of your loads, and your chamber headspace. A long chamber stretches cases more, and when you resize them, if you full-length resize 100%, a case stretched further has its shoulder pushed back more, and the extra brass from that has to go somewhere? One place it goes is into the neck length.

The X-die uses a mandrel with a step in it to limit case growth. The instructions have you trim the case to the minimum number (1.740" in .223). The brass grows from that length forward until it runs into the step, then grows no more. Everyone I've spoken to who has one says that it works. For a volume reloader using progressive loading equipment that is a Godsend, as he can trim once and never have to interrupt the progressive loading sequence again for trimming.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old February 18, 2010, 03:08 PM   #10
Hammonje
Senior Member
 
Join Date: January 11, 2010
Location: Lilburn, GA
Posts: 117
I trim my .223 Rem cases every time to 1.755". I do so for the sake of consistency. The same amount of brass placing tension on the bullet. COL affects point of impact....I bet case length would also. I would never compare my handloads to commercial ammo...the point of handloading, or my major point, is to generate superior ammo for a more reasonable cost.
Hammonje is offline  
Old February 18, 2010, 05:40 PM   #11
80viking
Senior Member
 
Join Date: December 8, 2009
Location: The Peoples Republic of Massac
Posts: 333
When I load the .223 for my match AR, I trim to the max. case length, 1.760. Why? Because I feel the neck is already too short on this case.

When I load blasting ammo I check every case with a max. length gauge, if the case goes thru it gets loaded, if it does not go thru it gets trimmed to 1.750 before it gets loaded. Crimping is done with a lee f/c die for consistency.
80viking is offline  
Old February 18, 2010, 09:52 PM   #12
mongoose33
Senior Member
 
Join Date: June 23, 2009
Location: Wisconsin
Posts: 228
I'm using the X-Die so I'm only trimming it once.
mongoose33 is offline  
Old February 19, 2010, 05:33 AM   #13
Randy 1911
Senior Member
 
Join Date: May 7, 2009
Location: Western Arkansas
Posts: 273
I resize and then measure. If it is over 1.760 it gets trimmed to 1.750, which is about every other time.
__________________
Been Reloading 27 Years
NRA Member
Member Old Fort Gun Club www.ofgc.org
Randy 1911 is offline  
Old February 19, 2010, 05:46 AM   #14
russaz1911
Member
 
Join Date: February 11, 2006
Posts: 16
Accuracy or quantity?

If you are loading for pure accuracy then you'll want to trim all of your brass to the length of the shortest case the first time that you load them. Same goes for Quantity loading but after the first trimming you should select about 10% of your cases and measure them to find out how much they are stretching. Always measure your cases after they have been sized.

I shoot 600 yard benchrest competitions. For my bench rifle I trim my brass once and won't trim it again unless it actually hits the end of my chamber, at which point I trim all of my brass to match the shortest case or take .005 off, which ever is greater. But the chamber if my bench rifle is so tight that no sizing is required to reload. Just punch the primer, clean the case, prim, load.

After a few firings you should notice that the cases are stretching less. By the time you have trimmed your brass for the third time it will probably be worn out unless you anneal your cases.
russaz1911 is offline  
Old February 19, 2010, 01:09 PM   #15
3085R
Member
 
Join Date: July 23, 2009
Location: Southern Illinois
Posts: 23
Because I have too much time on my hands, I trim my rifle brass during each reloading cycle. The RCBS 3-way cutter makes it somewhat less painful. Typically trim to the book trim number of 0.010 shorter than SAAMI spec.

Again, too much time, I measure each brass after sizing and before trimming. I've found that like everything else there is a typical distribution of growth lengths. In my 308 average case growth is 0.005 but some grow as much as 0.012 and some as little as 0.001. I've started setting aside cases that grow less than 0.002 and more than 0.008 for foulers as these are the outliers in the spread. The "reject" lot typically accounts for 6-8% of the total lot.

Is this too much attention to detail?
3085R is offline  
Old February 19, 2010, 07:51 PM   #16
Clark
Senior Member
 
Join Date: December 4, 1999
Location: WA, the ever blue state
Posts: 4,678


I tried to trim brass.
10 gallons of 223 is allot of trimming.

I got so I could trim faster but...

I made a fixture to measure the case space of each chamber.
Then I measured the headpace of each chambers.
Then I measured the headpace of the ammo I made.

The max brass length is the chamber case length - chamber headpace + ammo headspace.

That is the firing pin will put the case forward, and that has to be taken into account.

So for a (5) 223s, the worst was the Bushmaster:
d) Bushmaster 1.786" - .008" = 1.778"

And that is longer than 1.760", but the brass keeps growing.

The pressures I was testing for brass growth was way above SAAMI for 223 and a little above 5.56.

At that pressure with FL dies, the brass would grow fast.

Then I tried using the Lee Collet die on the single shot 223s.
The brass grew very slowly at high pressures.

What does it all mean?
The trick may be to neck size and NOT trim.
Clark is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 03:56 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.11277 seconds with 8 queries