Had a problem with my AR today

[kid_couteau]

Hi All

I was at the range today with my AR and some other guns and I had a problem

I had a primer not go off when I pulled the trigger.. After waiting the usual few moments for safety I tried to eject the round and the bolt was locked in place.

Is this a common thing? If the round does not fire the bolt is locked shut?

To fix the problem I had to take the upper off, reset the hammer, put it on safe, reassemble and then try firing again. Once the round fired the gun functioned ok.

Little help on this please. I am new to ARs

Thanks
Kid

 

[Husker1911]

You were unable to manually extract the unfired round in the chamber?

 

[Chris Orndorff]

Hmm...sounds familiar.

http://www.thehighroad.org/showthread.php?t=208736

 

[kid_couteau]

Hi

I wasnt using wolf ammo

When I looked at the bolt the "gears" of the bolt where interlocked with the receiver so that it could not back out

Kid

 

[Byron]

Who is the manufacter of the AR? Since these were new,had you cleaned prior to shooting? What was the brand of the ammunition? Byron

 

[kid_couteau]

It is a DPMS

I was testing some of my handloads

The funny thing is this thing eats wolf for breakfast with no worries.

Kid

 

[rbernie]

The brass may have been out of spec, or the bolt may have been too dry.

For what it's worth, I've had rounds that stuck in the chamber if I let 'em sit there for a bit. As a result, I clear a misfire immediately and do not let the rounds sit in the chamber.

 

[taliv]

kid, did you trim your brass? to what length?

 

[kid_couteau]

That may be it I did forget to trim the brass doggone it

 

[Grump]

My armchair diagnosis is either too-long headspace on your case = bolt jammed on the round too tight to fully lock closed, firing pin did not contact hard enough to fire, but the falling hammer fully locked the bolt. Round jammed too hard to allow manual extraction without doing the "pogo stick" maneuver, but the gas system (of course) could do the job.

OR, less likely, the case mouth was too long and jammed at the chamber/throat junction, same effect but different jam point.

Less likely, you *can* get the same effect with a bullet with an out-of-spec ogive that jams in the throat.

 

[MikeH]

I had a somewhat similar experience. After chambering my own handloads, the bolt wouldn't go into battery completely, and couldn't be extracted by pulling the charging handle either. I had to knock the bolt carrier (hence the bolt) completely into position using a hammer and screwdriver. After that the rounds did fire, extract, and eject normally.

The cases were trimmed, but I only neck-sized them after the first time. This starts to happen after 3 or 4 reloads.

 

[Byron]

What type of powder were you using and the charge amount? What primer were you using? What brand of cases are they? What type of lubricant are you using on the bolt carrier? Byron

 

[kid_couteau]

Two different loads

1st:

19 grains of Reloader 7
55 grain bullet

2nd:

21 grains of Reloader 7
55 grain bullet

Brass is mil brass with a WCC headstamp.

Winchester primers

Lube is synthetic oil with teflon

 

[dmftoy1]

How about pulling a bullet on those and checking the case length. (Just curious. )

Regards,
Dave

 

[kid_couteau]

I checked some of the ones I fired

They were about 6 thousandths over

 

[dmftoy1]

Thanks! I'm somewhat new to reloading for my AR and will be running my second batch through late this fall. (trimmed all for the first go-round) I was just curious how far over "max" you had to be to see bad problems.

Have a good one,
Dave

 

[rbernie]

Six thou over max trim length shouldn't pose a problem for anything but the tightest possible chamber. Are you full length resizing?

 

[kid_couteau]

Yes I full length sized

 

[Byron]

The Alliant Powder data indicates 20.5 grains of Reloader 7 is max. I wonder of the combination of the thicker military brass,1/2 grain over max charge and being 6/1000ths too long made a combined to create the locked bolt.Were you outside at the range?If so, summer temperatures could increase the pressure. Byron

 

[kid_couteau]

My 45th edition Lyman manual lists Reloader 7 at 20-22 grains for 223

According to a friend of mine the people that make the charts started downloading the charges because people were going over the max amount and blowing up. Mine is older and doesnt have that problem.

See ya

 

[rbernie]

Which load locked the bolt - the 19gr or 21gr? If the 19gr worked fine, I'd chalk this one incident up to a hot load and see if it ever repeats with normal loads...

 

[kid_couteau]

I am not completely sure but I think it was both loads that did it

Thank you
Kid

 

[pcf]

Couple thoughts on tough extraction, with loaded rounds....

Borrow/buy a .223 case guage and check your cases, Stoney point and Dillon make them. Most likely cause is that your not resizing enough, the shoulder need to be pushed back just a smidge more. Or you can lower your sizing die an 1/8th turn at a time until the cases don't stick.

Make sure your shell holder and resizing die are made by the same company. Mixing an matching shell holders and dies can prevent you from being able to resize correctly. I've always had problems with Lyman shell holders and RCBS/Hornady dies, just can't get the sizing die screwed down far enough.

Did you check your bullet seating depth and make sure that the bullets are not getting jammed into the lands. Happens even with "5.56 NATO" chambers.

Every fifth round or so put a dab of lube on the inside of a case neck, this will keep the expander from pulling the case shoulder out while resizing.

You may need a small base sizing die, some chambers are a bit on the tight side, combined with very little leverage to manually extract cases, the only solution may be a small base die. (pretty rare and usually with "Match" chambers)

Why it didn't fire? I'm not even going to guess.

 

[taliv]

kid, step two in reloading is to buy yourself a case gauge. it answers all these questions pretty fast. although go/no-go gauges have been hotly debated on the forums before, I wouldn't diddle much with ARs without one. The combination of a gauge to check your cartridges and a gauge to check your chamber seems kind of like common sense to me.

however, i agree with rbernie that .006" over max is highly unlikely to be your problem.

take one of your resized cases (unprimed), seat a bullet in it and see if you can close your chamber on it.

 

[JohnKSa]

Next time slap your bolt assist to finish chambering the round and you should be good to go.