My first AR and a Mystery

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Last Friday I finished up assembling my AR - first one I have owned. I used a Palmetto stripped lower, the Palmetto lower build kit, and a Palmetto 5.56 upper.
Off to the range Sunday to sight in. I have been reloading .223 for over 20 years for bolt guns, so have lots of components. I did not want buy any factory ammo, so I used a hand load that I had worked up for one of my bolt actions. The load was a commercial case, fully resized with RCBS dies, and trimmed to spec. The bullet was a Nosler 55 gr. jacketed. Powder charge was 22.5 gr. of X-Terminator with a CCI #400 primer. My Sierra manual shows a beginning charge of 22.7 gr.for ARs, so I was confident that the load was safe, although maybe a bit light.
I loaded one round into the Pmag, and it chambered just fine. Pressed the trigger, and the noise and recoil seemed normal. However, the bolt did not lock back, and when I tried to open it, it was stuck. I could not get it open at the range, so when I got home, I squirted some CLP down the barrel and on the bolt. After it soaked for a couple of hours, I tapped the rifle butt down on a chunk of 2x4 while pulling on the charge handle, and the action opened. The empty case stayed stuck in the chamber, so I tapped it out from the muzzle with an old cleaning rod. Now I am wondering why the case got stuck in the chamber. I thought I had thoroughly cleaned the barrel and chamber before firing it. the only thing I can think of is that there must have been some grit or something in the chamber that I missed.
Any ideas, thoughts?
 
if it chambered then it was probably sized alright...I small base size for some but FL for others. Did the rim look ok?
 
First thing I notice is the under charged load. That itself will stop the bolt from going back far enough to lock the bolt back. You probably didnt move the bolt far enough to even eject the round.
 
Did you try a few loaded ones in a mag and pull the charging handle to eject them first? Its weird the bolt didn't lock back. The one shot test is what I use to make sure I have the gas tube adjusted correct. Is this brass have a lot of firings in a bolt gun
 
as I understood it, the case stayed in the chamber even when he beat the bolt open... curious here. short stroking would still have held onto the case.
 
how long has it been since you trimmed your brass? What did the neck look like after you got the case out?
 
I had trouble with 204 brass that had multiple firings in a bolt gun and then I fl sized it for a new ar15 build, and it did the same thing u explain I think. I couldn't get enough out of the die. Then I got a SB sizer and used different brass and it worked fine. Mine was a shilen barrel though, and I think they run a tighter chamber.
 
I size with SB dies and I get a similar situation. When I chamber a round, about 1 in 3 won't eject if I pull on the charging handle without firing. I normally grab the charge handle and smack the rifle down on the but, then the un-fired round ejects. Factory ammo doesn't do this, not sure whats up? I'll be following this thread!
 
You never said what your chamber was. Is it a .223 or a NATO 5.56? If it's a new tight chamber (.223) I would recommend neck resizing along with full length resizing. I do not use the small base dies. I've never had the base hang up in a semi auto but I have had the necks hang up in a .223 chamber just like what happened to you.

Lastly, if it was a brand new barrel did you give it a brushing and run some patches through it prior to shooting it? It could of had some metal filings in it from being machined.

kwg
 
Originally Posted By: bushyif it chambered then it was probably sized alright...I small base size for some but FL for others. Did the rim look ok?

If it is sticking I would say they are not, my friend has a dpms that will not run loads prepped and then measured with a wilson case gauge, they have ran in 4 different AR's that I've owned and will try them in a 5th shortly.

Powderburner do unfired rounds stick also?
 
Originally Posted By: Mo LassisDid you try a few loaded ones in a mag and pull the charging handle to eject them first? Its weird the bolt didn't lock back. The one shot test is what I use to make sure I have the gas tube adjusted correct. Is this brass have a lot of firings in a bolt gun

Trying a few loaded rounds and see how they chamber and eject sounds like a good idea.
I would also thoroughly clean the BCG, and remove the extractor too (hold it in place with your thumb when you push the pin out).
Shine a light into the chamber for examination. A chamber brush while not needed very often, is important to have IMO.
Light/low power loads can cause problems.
The bolt not locking back can be the magazine; I have a rifle that don`t lock back reliably when using one mag. out of several..others work fine.
I also agree that the brass may not be sized quite right, and the load/unload of a few rounds should give you an idea.Most of my reloads will chamber even when the bolt is released slowly, but sometimes take just a little push forward with the FA, or thumb on the bolt.
 
Powderburner,,,,Chuck a piece of cleaning rod with your chamber brush attached into a cordless drill motor and after applying a few drops of oil on the brush, spin it in the chamber for approximately 30 seconds and then clean out the remaining debris with patches or a .38 cal. bore mop...

I had the same problem years ago with a new AR and that was the solution given to me by the owners of CMMG and it's a standard part of my cleaning routine anymore...Many times, there is a bunch of gunk that is left over in the manufacturing process and it will lock up brass upon firing if not cleaned out initially...If you are shooting a high round count at high speed, it can also be the cause of sticking brass due to debris build up...Not all powders burn with the same degree of cleanliness...

Also, the next time you have a round (live or fired) that is stuck in the chamber...rather than pounding on the weapon with a 2x4 or any other item, slam the weapon straight down on a solid object or ground very sharply om the butt stock, just make sure the muzzle is away from your face/body, and it will normally unlock the bolt and eject the problem round...
 
This is a follow on to my original post. First, to clarify, the bolt failed to lock back because it never did open in the first place. I opened it by tapping the butt down on a firm surface while pulling down on the charging handle. I did not beat it open with a 2x4! When I got the action open, I found the case still firmly stuck in the chamber.
I removed the stuck case by inserting a cleaning rod into the muzzle, and tapping it. When the case was removed, it showed that the rim was torn by the extractor when the bolt was opened.
I went to the range this AM, and fired 12 rounds of various factory loads that I had accumulated. All fired and functioned perfectly. I deduce that there was something about that first hand load that was not right. My next step is to load up a few rounds with carefully prepared once fired LC brass, and see how it goes.
Thanks to all for your comments and suggestions.
 
Go back and read my last reply about the under charged load. The AR requires gas pressure to run the action. I just went through the exact same thing with my 6.8 while trying to adjust the gas block. Your load was not hot enough to push the bolt back. It moved it a little and pushed the expanded empty case back into the chamber. That is why you could not pull it back without tapping the gun. It was not long brass and you do not need SB dies. If the brass was to long, it would not have locked into battery and would not have fired. Start at least mid way between minimum and maximum if you want the gun to function. I usually start 1 grain below max.
 
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