The Firing Line Forums

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

Reply
 
Thread Tools
Old June 27, 2009, 07:20 PM   #1
The Duck
Junior Member
 
Join Date: June 27, 2009
Location: South of Tucson AZ
Posts: 3
.223 oal??

I understand that factory loads for .223 are 2.25 inch. But I also understand that the distance from the bold face and the rifleing are different in many barrels.
I have found that (in my weapon) a factory match load (77grain) measures X from the mussel of the weapon. I place a 80 grain MK into the chamber and slide it in until it stops (no pressure added) and that distance is now is X minus approximatly 0.38 inches. I now place a 77 grain MK int the chanber and the reading becomes approximatly X minus 0.25 inches.
I understand that the ojive of the bullet will change the distance the bullet travels into the barrel before encountering the rifleing.
My question is how do I figure a OAL for my reloads using these two bullets.
I have read that the shorter the bullet jump to the lands makes for a more accurate load. But, I also read that that jump distance should be at least 0.002 inch.
I have loaded some 80 grain MK to OAL of 2.35 inch and have had good luck with them. But do I have room to go longer, and should I?
The Duck is offline  
Old June 27, 2009, 09:32 PM   #2
QBall45
Senior Member
 
Join Date: April 5, 2008
Location: South Central Minnesota
Posts: 583
What rifle are you talking about? AR15 or a bolt gun?

Factory 223 ammo is loaded to 2.25 so that it will fit into an AR15 mag.

How to answer you real ? Well that depends really on your rifle.
QBall45 is offline  
Old June 27, 2009, 10:33 PM   #3
The Duck
Junior Member
 
Join Date: June 27, 2009
Location: South of Tucson AZ
Posts: 3
.223 oal

AR 15
The Duck is offline  
Old June 27, 2009, 10:38 PM   #4
The Duck
Junior Member
 
Join Date: June 27, 2009
Location: South of Tucson AZ
Posts: 3
.223 oal

yes i understand i depends on the rifle but what i really would like to know is, just how close to the rifleing should the bullet get before it is too close?
i know that loading so that the bullet comes into contact with the rifleing could cause an over pressure.
i am not worried about using the rounds in a mag. i am tring to find a round that preforms well at long range. loading one round at a time.
The Duck is offline  
Old June 28, 2009, 07:40 AM   #5
firewrench044
Senior Member
 
Join Date: July 9, 2007
Location: Fort Pierce, Florida
Posts: 187
the 77gr bullet is made to be used in the magzine,
that legnth is 2.260 inch

the 80gr bullet is made longer to be loaded one at a time through
ejection port (usualy used at 600 yards )

the barrel should have 8 to1 or less twist to stablilise bullet

the distance off the lands varrys with the brand of bullet and the brand
of barrel
my Bushmaster shoots best at 25 thou. off, most other brand barrels
shoot best at 5 to 15 thou. off the lands

Work up your 80gr load, then vary the length to find the distance
off the lands that your rifle likes
firewrench044 is offline  
Old June 28, 2009, 01:02 PM   #6
Alleykat
Junior member
 
Join Date: July 26, 2007
Posts: 3,668
I recently built an AR, using a RRA 20" bull varmint barrel with Wylde chamber. Leade is much shorter than with my other .223s. Have to load @ 2.220" or shorter, or I'm into the lands, with 55gr. bullets.

Also recently built an AR, using M4 YHM chrome-lined barrel. Glad I used the old Stoney Point tool to determine length to the lands. Again, much shorter than with other .223s.
Alleykat is offline  
Old June 28, 2009, 02:16 PM   #7
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 10,189
The Duck,

The answer changes with every bullet that has a different ogive shape. I recommend you get a pair of calipers and the Hornady Overall Length gauge and find out where your gun's throat is and how deeply each bullet has to be seated to avoid crushing into it? Typically, longer bullets that are still suited to magazine feed, like the 77 grian SMK, will be able to seated out to SAAMI maximum COL (2.260"). Bullets seated longer to get them closer to the throat in your chamber will have to be fed singly.

You can develop loads that touch the lands if that works out in your gun. They will have a little less powder in them than those made with the bullet seated off the lands because the jump lets the pressure drop a bit. How much depends on the seating depth and the length of time gas can bypass the bullet before it enters the lands and obturates the bore, sealing the gas off. I generally find performance sweet spots with the bullet touching the lands, or with it seated somewhere between 0.020" and 0.040" off the lands. Another seating depth sweet spot, though usually not quite as tight at the others, will tend to occur when the bottom edge of the bullet's bearing surface (the cylindrical portion that touches down in the grooves of the rifling) is seated about 1 caliber into the case, as long as the top of the bearing surface is still above the edge of the mouth.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Patron Member
Unclenick is offline  
Old June 28, 2009, 08:26 PM   #8
42769vette
Member
 
Join Date: January 11, 2009
Posts: 86
I recently built an AR, using a RRA 20" bull varmint barrel with Wylde chamber. Leade is much shorter than with my other .223s. Have to load @ 2.220" or shorter, or I'm into the lands, with 55gr. bullets.

Also recently built an AR, using M4 YHM chrome-lined barrel. Glad I used the old Stoney Point tool to determine length to the lands. Again, much shorter than with other .223s

this statement shows the diffrence in the exact same guns. rra 20" bull upper and im loading 2.25 and not in the lands. i soft seated a few and my lands are 2.4-2.5.
42769vette is offline  
Old June 29, 2009, 04:47 PM   #9
Alleykat
Junior member
 
Join Date: July 26, 2007
Posts: 3,668
Quote:
this statement shows the diffrence in the exact same guns. rra 20" bull upper and im loading 2.25 and not in the lands. i soft seated a few and my lands are 2.4-2.5.
Suggest you try a more precise method than "soft seating"!! Also, could be the difference in the profile of the bullets I'm using vs. the profile of the bullets you're using.
Alleykat is offline  
Reply

Tags
.223 , oal , reloading

Thread Tools

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 06:43 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2014 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.07331 seconds with 7 queries