Bolt not closong all the way

[shotgunred50]

Hey guys I have a problem with misfires/bolt not closing completely on my AR. I took it to a gunsmith and he told me that I need to shoot about 100 rds through it and not clean it. He said the residue will help lap/break in the lugs on the bold face and reciever so that the bolt will lock up every time. I started having problems with it last winter. I had a misfire on a coyote and when I tried to rack in a fresh round the bolt and charging handle was frozen. Same thing happened a couple weeks ago on a deer. I was able to free up the bolt back home after the gun warmed back up but it still took considerable force to get the bolt to let go. I am now using break free cleaner/lube per the gunsmiths advise. Just wondering if you guys think wasting 100 rds will actually help my problems. Btw the misfired rounds had a very slight mark on the primer, not even close to enough force on the firing pin to set it off. The gunsmith said all my springs looked good and he thinks its doing this because the bolt os not fully going into battery. Thanks and shoot str8!

[ryutzy]

Sounds a little off to me and possible a lubricant issue. I used break free for a while, but it feels more like a cleaner than a lubricant to me. Use a liberal amount of a quality gun oil or better yet, try Millitec. I started using it on my AR recently and love it so far. I cleaned and then heated up the action with a torch until it was too warm to hold for very long. I then doused it with Millitec and let it sit. The metal seemed to soak some of it up. I then reassembled the action and so far it has been operating more smoothly than any gun oil I have tried.
If better lubricant doesn't fix your problem, I'd take it to a different gunsmith. Someone else may chime in on their thoughts.

[204 AR]

Ok you didn't say what caliber or ammo you're using, but if you're using factory ammo, it's a gun problem that better oil, more break in Might cure.

If you're using reloaded ammo you're problem is probably that the cases aren't resized fully. Take a fired case, resize it at the setting you're using now, and try to chamber it. It should chamber easily and lock up, and pull back out just as easy. If it sticks, it's not resized enough. Then turn the sizing die down 1/4 turn at a time and keep trying it, at some point it should function well.

HTH

[ClaimJumper]

My questions for you,

1). BCG and barrel matched? same make? or were parts just slapped together
2). Reloads? or factory? COL?
3). Full length sized? or Neck?
4). Virgin brass? or new to you?

You can only shoot full length sized cases, and some need a small base die just to work at that

Most times the ammo is the cause. Wolf has lacquer coating on their cases. If you shoot it "hot" place the safty on with one in the pipe

it may stick because the lacquer melts like glue and is very hard to extract the case. This also builds up and causes problems until you flush the chamber with

brake cleaner. You state the bolt never closes, that's a case size issue to me.

I was able to free up the bolt back home after the gun warmed back up but it still took considerable force to get the bolt to let go

Never heard of "Shoot 100 rds" to make it fit..It should never fail. ever.

[Grayfox]

If your AR will not chamber and close on Factory ammo have your headspace checked. You have a tight chamber and your bolt will not fully close. The fireing pin will will only be able to lightly dent the primer. This is a saftey feature so the rifle will not destroy itself and hurt you.

If your handloading then you are not sizeing your cases to push the shoulder back at least .003".Next check your case overall lenght and trim it to minimum lenght. You will need a caliper and case guage to measure exactly .003".

Take the upper off your lower and turn it so the carrier/bolt is faceing up. Pull the chargeing handle back to open the bolt. Put your resized case in the chamber and slowly push the bolt closed with your finger. If the bolt does not rotate to it's fully closed you need to size the case some more. This will work if you do not have a caliper and guage. Once you find where the bolt closes,adjust your die about an 1/8 more turn down. This will give you a litle margine for brass springback when sizeing.Now try all your resized cases in the chamber to see if they fit. If they fit then your dies are good to go and they are set up for your rifle.

Grayfox

[shotgunred50]

Question
1). BCG and barrel matched? same make? or were parts just slapped together
2). Reloads? or factory? COL?
3). Full length sized? or Neck?
4). Virgin brass? or new to you?

Answer
1. Model 1 sales varmint kit gun with predator custom shop lower reciever.
2. I shoot both. most of the time fresh brass will chamber as well as new ammo.
3. I used RCBS FL dies. I am thinking the problem may be in these dies being crap?!?!?! BTW I ALWAYS make sure the shellplate makes complete contact with the bottom of the die. This is an area where im confused about people saying give it another 1/8 or 1/4 turn. If its bottomed out it shouldnt make a difference?!?!?!
4. Virgin remington brass with remington 71/2 benchrest primers.


Is it really worth going to some high end dies? Its looking like I may as well throw all my once fired brass away unless I can somehow get it sized to chamber again?

[Lead Lobber]

When Full Lenth sizing you must adjust the die to where your handle will "cam" over. Usually 1/8 turn past touching does the trick for me on my RCBS dies.

[shotgunred50]

Well I have a lee press, not sure what the model is but it seems to just hit top dead center and thats it. I guess I need to see this in action to understand fully. It is hard for me to understand because I load .45 acp by the thousands and they go bang every time. Same with .30-06.

[ClaimJumper]

where your handle will "cam" over

Lead lobber is correct.

[Valar]

I use a thin smear of synthetic grease on the slide points on the bolt. Cycle is smoother with faster consistent lockup.

[bow shot]

What the brothers as saying is:

1) With only the shellholder and no sizing die in the press, bring the ram of the press up, (handel relaxed, and down)
2) install the die, screwing it into the press till it touches the shell holder
3) now bring the ram down (handel up) and screw the sizing die 1/8 turn more and lock it down with the locking ring.

Now when you size, your ram will contact the shell-holder when you bring let the lever down (like before) without exerting any pressure on the lever. BUT... you now need to apply pressure to the lever.. you'll feel it cam over, and then come to a positive stop.

Just read RCBS' or any die mfg's instructions... you'll get it and go Oooohhhh !!!