The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Art of the Rifle: General

Reply
 
Thread Tools
Old March 8, 2010, 07:12 PM   #1
studman5578
Senior Member
 
Join Date: March 4, 2009
Location: Varying between 1 and 3 hours from Chicago
Posts: 152
Chambering problems in an AR15

Finally finished my first AR that I've been slowly building for about a year now. I bought a match upper the other day and for some reason, my rounds will not go in and come out of the chamber easily. The barrel I bought was made by a smaller independent manufacturer, with a Colt upper. I've only tried hand loaded rounds so far and will go out to get a box of factory to check it to the actual standards. I used lee dyes for the reloading.

When I put the round in the chamber, the bolt will close completely with some rounds (ie the bcg is flush with the end of the upper receiver if you have it broken down), with others the round will not come out without excessive force. I haven't taken it to a range yet and wasn't firing the rounds I put in the chamber, merely checking to see if they'd fit. I'm weary of trying to load a round the standard way by just pulling back the charging handle because I don't want the gun to ram-fire.

Is this how it is with the 223 round in general? I was under the impression that because its semi-auto, the round should slide in there easily, so as not to jam the gun. any information/personal experiences will help alot.
__________________
Rev 5:13 "To him who sits on the throne and the Lamb be praise honor and glory and power, for ever and ever"
studman5578 is offline  
Old March 8, 2010, 07:15 PM   #2
Jimro
Senior Member
 
Join Date: October 18, 2006
Posts: 5,675
Quote:
I've only tried hand loaded rounds so far
Well there's your problem...

Jimro
__________________
"Gorsh" said Goofy as secondary explosions racked the beaten zone, "Did I do that?"

http://randomthoughtsandguns.blogspot.com/
Jimro is offline  
Old March 8, 2010, 07:49 PM   #3
Technosavant
Senior Member
 
Join Date: May 29, 2007
Location: St. Louis, MO area
Posts: 3,913
Does the barrel have M4 feed ramps? The upper? If you're using a non-M4 ramped barrel in a M4 ramped upper, the bullet nose is likely to get caught in the resulting pocket.

Otherwise, I'd strongly suspect the ammo.
Technosavant is offline  
Old March 8, 2010, 08:08 PM   #4
Slamfire
Senior Member
 
Join Date: May 27, 2007
Posts: 4,133
This is a very common problem with gas guns. You have brass, fired in a different rifle, sized by a standard sizing die, and it is oversize for your new rifle.

I am assuming that you are using a standard sizing die, and that you did not set up the die with a cartridge headspace gage.



I have a bunch of Wilson cartridge headspace gages. They cost $15.00 or so. There are two ledges on the back. Each ledge corresponds exactly with “GO” and “No Go” chamber headspace gages. The deeper ledge is the “Go”, the upper ledge is the “No Go”.

Depending on the resolution of your screen, these ledges might be hard to see in the attached picture. The difference between "Go" and "No go" is only around .006".

You set up your sizing die by simply sizing a case then dropping it in the gage. If the shoulder to base length of the case is above the “No go”, you turn the die in a little more to size the case a little more. If the case base is below the “Go”, you are oversizing your case and need to back the die out a bit.


I recommend to size to gage minimum for gas guns. Bolt guns are less fussy with ammo so you can play around with shoulder depth to extend case life.

There are more sophisticated gages on the market and many bolt gun users set the case shoulder back an exact amount, like .003” or so.

Wilson gages are cut with a special reamer: the distance from shoulder to base is correct but the gage is cut big between the shoulder and the base. You can drop a fired case into one of these gages and determine from the expanded case if you have a headspace issue with your rifle chamber. Plus or minus a little error.

There have been a few times when I found I could not size a case below the "No Go" of the gage no matter how much I turned the sizing die down. That is when I figured out that the die was too long and I had to grind material from the bottom of the die to get the sized cases to the proper length.

You will occasionally read threads where this happens to other folks. They completely full length size a case and can't figure out why they are having stiff bolt closure. Without gages they did not know they had a sizing die problem.

You will also read threads where reloaders claim that small base dies "over work" the brass. Mostly likely they are oversizing their cases in the small base dies and don't know what they are doing because they don't have a gage.

I use small base dies for all of my gas gun calibers: 223, 308 and 30-06. I would use them for other calibers if they were available. It is highly likely that your once fired brass is too fat. Even if you size the stuff to the correct length, you need a small base die to size it to fit in your chamber.
Slamfire is offline  
Old March 9, 2010, 12:17 AM   #5
Tim R
Senior Member
 
Join Date: November 30, 2004
Location: God's side of Washington State
Posts: 1,601
If you did not bring your die down to touch the shell holder with the ram all the way up and then add a another 1/4 turn to the die before locking it down. Then you more than likely did not get your case sized enough.

I shoot 223, 308 and '06 in service rifles for High Power and John C. Garand matches and have not had to use small based dies for any of it. Out of the three, 223 needs the extra 1/4 turn on the die the most.
__________________
God Bless our Troops especially our Snipers.
Tim R is offline  
Old March 9, 2010, 01:35 AM   #6
studman5578
Senior Member
 
Join Date: March 4, 2009
Location: Varying between 1 and 3 hours from Chicago
Posts: 152
I did the 1/4 turn when i loaded my ammunition. I think I'll pick up one of those gauges because I've got about 300 rounds of this hand-loaded stuff that I need to pick through. I think .223 Remington has been the biggest pain for me to load thus far. First I used the Rem SR primers for about 100-150, now I've got this gauging issue. I'll probably have worn out the shell holder on my bullet puller by the time I'm done with this... Learning my lessons the hard way.
__________________
Rev 5:13 "To him who sits on the throne and the Lamb be praise honor and glory and power, for ever and ever"
studman5578 is offline  
Old March 9, 2010, 01:53 AM   #7
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 3,767
There is one issue new reloaders keep discovering.

Your seating die also has a crimp function built in.

It is a topic of controversy as to whether or not you should crimp the bullets on a .223.I'll leave that alone.What you do not want to do is apply excessive crimp,as it will actually deform the brass.

Just for fun,back your seater die away from the shell holder,maybe the thickness of a penny or so.Or,very carefully read you die instructions.
HiBC is offline  
Old March 9, 2010, 09:51 AM   #8
Slamfire
Senior Member
 
Join Date: May 27, 2007
Posts: 4,133
Quote:
I did the 1/4 turn when i loaded my ammunition
.

The difference between Go and No Go is .006" for a 308. I don't know what it is for a .223, probably close.

See that tiny difference between the Go and No Go ledge in the picture of the Wilson gage? Just cranking the die down random numbers of "quarter turns" is a crude and imprecise way to improperly size your brass.
Slamfire is offline  
Old March 9, 2010, 11:24 AM   #9
tirod
Senior Member
 
Join Date: January 21, 2009
Posts: 1,219
Hand cycling a semi auto action will create problems by the dwell time of gravity. I don't think this is the problem, but it happens all the time.

LET THE BOLT SLAM HOME. Do not ride the bolt. The forces involved are identical to the action cycling. The bolt is at the rear most portion of travel when it reverses and moves forward. It's designed to work that way, not hand fed.

You won't get a slam fire unless you are using a really sensitive primer. The AR firing pin does touch it when chambering, it doesn't cause slam fires on military ammo, and no known research shows that sensitive civilian primers are any better at improving anything in the AR. Very few seem to be that touchy, anyway. Getting them flush when seating is far more important.

M4 feed ramp cuts were designed by Colt to improve reliability in full auto fire - the ancient cheap magazine design will let one rattle loose in combat and having the cuts improves reliability feeding it. There's million's of M16's without them, they have a softer cyclic action and don't pop rounds out of the magazine as much. It's a carbine length action thing (big hint about HD and SHTF use - go to mid length.)

This is a common situation in new AR's - hand cycling the action is kinda like testing to see if the clutch will withstand a full power dump at the dragstrip by doing it at idle. Not the same thing at all, sure it stalls. In this case, filling up with regular (factory ammo) and going to the strip (range) is needed first. Then science out the special fuel when the platform is known to be good to go.
tirod is offline  
Old March 9, 2010, 11:45 AM   #10
studman5578
Senior Member
 
Join Date: March 4, 2009
Location: Varying between 1 and 3 hours from Chicago
Posts: 152
thanks for all the help. i'll probably get one of those gauges this week and get a new bullet puller while i'm at it...
__________________
Rev 5:13 "To him who sits on the throne and the Lamb be praise honor and glory and power, for ever and ever"
studman5578 is offline  
Reply

Tags
223 remingtion , ar15 , build , chamber

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 06:06 AM.


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 0.09199 seconds with 9 queries