Question about .223 case length

tpcollins · June 21, 2012, 07:41 AM

The SAAMI case length for .243 Winchester is 2.025"-2.045". In .204 Ruger it's 1.830"-1.850". Both of these have a range of .020". However, the spec for the .223 is listed as 1.730"-1.760" which is a .030" range. If my math is correct, it doesn't appear that either length will allow for a full caliber length of bullet seating in .223.

If you're reloading for an AR, is there any advantage to one end of the specification versus the other? Thanks.

angus6 · June 21, 2012, 08:13 AM

Seems that 1.750 is a pretty common length to trim to

moxie · June 21, 2012, 09:41 AM

Haven't noticed any difference in performance of different OALs within the range.

"Max" length is 1.76". "Trim to" is 1.75".

My OALs (55FMJBT only) work out to the ~2.240-2.255 range.

OAL will also depend on and vary with the bullet weight and type. They vary from 40 all the way up to 80.

wncchester · June 21, 2012, 03:32 PM

"... it doesn't appear that either length will allow for a full caliber length of bullet seating in .223"

Quite a few cases don't have caliber length necks. ???

Don't think SAAMI specs "trim-to" lengths. Modern loading books list an arbitrary trim-to at 10 thou less than max for those timid souls who fear making a decision on their own. Long before they started doing that I choose 5 thou less than max for myself, and that's what I still aim for, but I know I'm not going to blow anything up if I go shorter. (And I know exactly how long each of my chambers are so I also know how much longer I can go without blowing anything up.)

HJ857 · June 21, 2012, 04:01 PM

Agree with wncchester, my trim length is 1.755, and I'll accept any case between 1.750 and 1.760. Or in other words, my target length is 1.755 and I'll accept a +/- 0.005. I do not load for absolute precision though.

I think if you're loading for precision, then every factor counts to some level. So a consistent case neck would one of those factors, and if you use a crimp, and I'm pretty sure you do, then that consistent neck length should hit the die at the same spot every time.

If not loading for serious precision, then I wouldn't worry about it.

a7mmnut · June 21, 2012, 04:03 PM

You are correct. That's why the .222 is almost always more accurate. BTW, the .204 is based on the .222 Rem Magnum case.

-7-

mohr308 · June 22, 2012, 01:44 AM

i trim mine to 1.755 also, never had a problem. I am loading my ammo for an AR-15, plus I taper crimp all my ammo about .0015-.002"

243winxb · June 22, 2012, 12:00 PM

Quote:

If you're reloading for an AR, is there any advantage to one end of the specification versus the other?

Longer would be better than shorter. Longer provides more neck tension. This is needed for an auto loader. Military ammo requires a bullet pull of 45 lbs. As other have said, use the standard trim to length. Not the minimum usable length listed by SAAMI. http://www.exteriorballistics.com/re...sgunreload.cfm

Edward429451 · June 23, 2012, 02:07 AM

I stay on the longer side also. As long as they are all consistently the same length then thats best. You can trim to a shorter length case as was noted, but the potential problem in shorter necks is there has to be enough neck to hold the bullet securely. (neck tension). This is why longer is better.

If you want to trim short for whatever reason, trim a few cases and seat bullets and test them against a bathroom scale to 50 lbs and see if the bullet moves. If it gets shorter, you need more neck.

eldorendo · June 25, 2012, 06:11 PM

I trim my AR-bound .223 brass to 1.740" when using the RCBS X die, per instructions. I then don't have to trim again. I've used o.a.l. out to 2.270"-or-so, but I'm having to load as short as 2.200" for some of my ARs.

June 21, 2012, 07:41 AM	#1
tpcollins Senior Member Join Date: February 18, 2009 Location: SE Michigan Posts: 558	Question about .223 case length The SAAMI case length for .243 Winchester is 2.025"-2.045". In .204 Ruger it's 1.830"-1.850". Both of these have a range of .020". However, the spec for the .223 is listed as 1.730"-1.760" which is a .030" range. If my math is correct, it doesn't appear that either length will allow for a full caliber length of bullet seating in .223. If you're reloading for an AR, is there any advantage to one end of the specification versus the other? Thanks. __________________ What direction did that last shot at Kennedy come from?

June 21, 2012, 09:41 AM	#3
moxie Senior Member Join Date: October 17, 2006 Location: TX Posts: 513	Haven't noticed any difference in performance of different OALs within the range. "Max" length is 1.76". "Trim to" is 1.75". My OALs (55FMJBT only) work out to the ~2.240-2.255 range. OAL will also depend on and vary with the bullet weight and type. They vary from 40 all the way up to 80. __________________ If you want to shoot...shoot...don't talk! Tuco USAF Munitions 1969-1992 RVN 1972-1973

June 21, 2012, 03:32 PM	#4
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	"... it doesn't appear that either length will allow for a full caliber length of bullet seating in .223" Quite a few cases don't have caliber length necks. ??? Don't think SAAMI specs "trim-to" lengths. Modern loading books list an arbitrary trim-to at 10 thou less than max for those timid souls who fear making a decision on their own. Long before they started doing that I choose 5 thou less than max for myself, and that's what I still aim for, but I know I'm not going to blow anything up if I go shorter. (And I know exactly how long each of my chambers are so I also know how much longer I can go without blowing anything up.) Last edited by wncchester; June 21, 2012 at 03:45 PM.

June 21, 2012, 08:13 AM	#2
angus6 Member Join Date: October 11, 2008 Location: N.E. Missouri Posts: 31	Seems that 1.750 is a pretty common length to trim to

June 21, 2012, 04:01 PM	#5
HJ857 Senior Member Join Date: January 9, 2007 Posts: 447	Agree with wncchester, my trim length is 1.755, and I'll accept any case between 1.750 and 1.760. Or in other words, my target length is 1.755 and I'll accept a +/- 0.005. I do not load for absolute precision though. I think if you're loading for precision, then every factor counts to some level. So a consistent case neck would one of those factors, and if you use a crimp, and I'm pretty sure you do, then that consistent neck length should hit the die at the same spot every time. If not loading for serious precision, then I wouldn't worry about it.

June 21, 2012, 04:03 PM	#6
a7mmnut Junior member Join Date: February 27, 2009 Location: NC Foothills Posts: 1,150	You are correct. That's why the .222 is almost always more accurate. BTW, the .204 is based on the .222 Rem Magnum case. -7-

June 22, 2012, 01:44 AM	#7
mohr308 Senior Member Join Date: January 15, 2012 Location: Western New York Posts: 466	i trim mine to 1.755 also, never had a problem. I am loading my ammo for an AR-15, plus I taper crimp all my ammo about .0015-.002"

June 23, 2012, 02:07 AM	#9
Edward429451 Junior member Join Date: November 12, 2000 Location: Colorado Springs, Colorado Posts: 9,494	I stay on the longer side also. As long as they are all consistently the same length then thats best. You can trim to a shorter length case as was noted, but the potential problem in shorter necks is there has to be enough neck to hold the bullet securely. (neck tension). This is why longer is better. If you want to trim short for whatever reason, trim a few cases and seat bullets and test them against a bathroom scale to 50 lbs and see if the bullet moves. If it gets shorter, you need more neck.

June 25, 2012, 06:11 PM	#10
eldorendo Senior Member Join Date: May 8, 2012 Posts: 239	I trim my AR-bound .223 brass to 1.740" when using the RCBS X die, per instructions. I then don't have to trim again. I've used o.a.l. out to 2.270"-or-so, but I'm having to load as short as 2.200" for some of my ARs.