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9/22/2017 12:11:25 AM
Posted: 9/9/2010 6:04:07 PM EDT
rockriver flattop and a stag arms lower. simply wont hold open bolt with mag inserted. have not shot the gun yet. the only thing i have done to the gun so far was to put a new grip on it and installed a madd mag lever...i took the lever off but it still wont lock. seems to be short throwing. im hoping this is an easy fix as i purchased this from someone thru he internet. any help would be appreciated.
Link Posted: 9/9/2010 6:07:07 PM EDT
Does it lock back manually?

Are you trying several magazines or just one?
Link Posted: 9/9/2010 6:11:18 PM EDT
wont lock back at all. ....i tried to hold down the release button and tried 3 diff. new magpul mags
Link Posted: 9/9/2010 6:12:31 PM EDT
[Last Edit: 9/9/2010 6:27:45 PM EDT by RLR350]
It might be something blocking the Bolt Carrier's rearward movement. What stock set up are you using?

When you pull the charging handle back, look in the ejection port. When the BCG is all the way to the rear, the face of the bolt should be behind the bolt catch. If it isn't I suspect you have the wrong spring, buffer or an A2 screw in an A1 stock - of course just a SWAG since I don't know what set up you have.
Link Posted: 9/9/2010 6:22:10 PM EDT
standard retractable 6 position i think. i dont think changing the grip had anything to do with it.....well , a pin fell out that had a point on the end of it but i put it back in......and i also took care when i changed the grip to re install the spring. the pin i assumed inserted with the pointy end inside the rifle, is that correct?
Link Posted: 9/9/2010 6:27:14 PM EDT
Yes - or down in the receiver and then the spring goes in on top of it.
Link Posted: 9/9/2010 6:29:28 PM EDT
hmmmm.....spring? well, i beter start lookin on the floor. any exploded views on ths site?
Link Posted: 9/9/2010 6:40:33 PM EDT
[Last Edit: 9/9/2010 6:42:33 PM EDT by a308garand]
Originally Posted By roadrunner2:
wont lock back at all. ....i tried to hold down the release button and tried 3 diff. new magpul mags

hmmmm.....spring? well, i beter start lookin on the floor. any exploded views on ths site?


If your bolt is going back far enough, and you do not have a rifle length buffer spring in a carbine length buffer tube (receiver extension) as posted above.......

The bolt catch is pressed upwards by the magazine follower. Sometimes, the finger of the bolt catch is not caught by Magpul follower but will work with USGI mags. The two magazines are slightly different in thickness and a slight difference can cause the follower to miss the bolt catch. Check with a USGI magazine.
This trouble is directly related to the lower receiver being slightly out of spec, not Magpul magazines.
See my post here:
http://www.ar15.com/forums/topic.html?b=3&f=66&t=479984


The pistol grip has a spring and detent contained within a hole as it is assembled onto the rifle. This spring and detent push against the safety lever, if it is missing, your safety lever will flop around. It will not be firmly held in Safe or Fire.
See the build it yourself like here:
http://www.ar15.com/forums/topic.html?b=3&f=4&t=226782

Link Posted: 9/9/2010 7:18:00 PM EDT
the finger is well over top of the magazine follower as in pic#4......but the bolt release has no tension on it.......this is frustrating...the guy i bought it fronm said it functioned fine.......i find that hard to believe. i assume the car stock is the proper setup(retractable).
Link Posted: 9/9/2010 7:20:40 PM EDT
[Last Edit: 9/9/2010 7:22:02 PM EDT by a308garand]
There is supposed to be a spring and detent behind the bolt catch. It pushed the catch down to clear the bolt, until the follower pushes it up to catch the bolt. If your bolt catch has little to no resistance and flops in place, spring is gone........

In here:
Link Posted: 9/9/2010 7:39:41 PM EDT
i see what you mean. i checked with a flashlite and saw that there is a spring............i did not take out the rollpin. i tried usgi mags with same results. well, so much for shooting tomm. i guess i will get some pics up for someone to look at and see where it goes. i dont think its anything major....im not too proficient at taking these things apart yet. i may have to take it to a gunsmith if i cant get it goin.
Link Posted: 9/9/2010 7:47:19 PM EDT
You might have the wrong detent under the bolt catch. I once put the pistol grip detent in the bolt hold catch hole (by accident). It would not lock the bolt back. The pistol grip detent is longer than the bolt catch detent. It would not allow the bolt catch to pivot far enough to engage the bolt.
Link Posted: 9/11/2010 3:41:50 PM EDT







it seems that all is in place here. im leaning toward taking out the rollpin on the bolt release and go from there? short of that, i may need some help from a smithy....
Link Posted: 9/11/2010 3:49:21 PM EDT
Try it without the BAD lever, there are sometimes problems with that setup.
Link Posted: 9/11/2010 3:52:25 PM EDT
i thought of that. same deal. ques.....should there be spring tension on the bolt release button when no mag is inserted? i get no movement at any time on it.
Link Posted: 9/11/2010 3:54:06 PM EDT
Link Posted: 9/11/2010 3:56:46 PM EDT
[Last Edit: 9/11/2010 4:01:40 PM EDT by locke12]
Originally Posted By roadrunner2:
i thought of that. same deal. ques.....should there be spring tension on the bolt release button when no mag is inserted? i get no movement at any time on it.


If you press on the BOTTOM of the catch lever, not the top where the serrated pad is, the little part of the latch below the roll pin. If you press there it should have tension, and movement.
Link Posted: 9/11/2010 6:28:51 PM EDT
roadrunner2, if you are in the CLE metro area, I'd be glad to take a look at it for you.
Link Posted: 9/11/2010 6:38:43 PM EDT
thanks muncie....im in athens county(athens ohio). i took a few more pics as a lastditch effort b4 i spend money on a smithy.................................






maybe someone can see something out of the ordinary..
Link Posted: 9/11/2010 11:09:30 PM EDT
Do you have a rifle length buffer or rifle length spring in a collapsing stock extension tube?
Do you have a A1 fixed stock screwed on with an A2 length buttstock screw?
Does it have some sort of aftermarket "buffer pad" glued or screwed to the front of the buffer?

All these can prevent the carrier from cycling completely to the rear to allow the bolt lock to engage.
I would start here.
Link Posted: 9/12/2010 4:00:57 AM EDT
Originally Posted By Milo5:
Do you have a rifle length buffer or rifle length spring in a collapsing stock extension tube?
Do you have a A1 fixed stock screwed on with an A2 length buttstock screw?
Does it have some sort of aftermarket "buffer pad" glued or screwed to the front of the buffer?

All these can prevent the carrier from cycling completely to the rear to allow the bolt lock to engage.
I would start here.


i purchased the rifle from a guy that already had the rr upper and added the safari lower. im really not proficient with taking all that apart and eyeballing the difference but i will have it checked out.
thanks for the info...

Link Posted: 9/12/2010 7:57:33 AM EDT
The photos that show the empty mag inserted and the bolt hold open still in the down position would mean that the bolt hold open is not pivoting. The mag follower is trying to push up the bolt hold open but it is not moving. If you feel comfortable remove the bolt hold open roll pin, remove the BHO, spring and detent. If you can not move the BHO with it the way it sits now then it has to be one of those components.

TC
Link Posted: 9/12/2010 8:46:19 AM EDT
will the bolt lock move easy?
I have seen people drop the hammer a few too may times on a lower (without an upper in place) and bent the frame so the bolt catch is hard to move.
Link Posted: 9/12/2010 9:52:35 AM EDT
I know how frustrating this can be. I had a similar issue with an assembled lower I picked up from my Smith (30yrs experience & excellent rep). No matter what mag I used (USGI, Lancer, PMAG, D&H, CP), bolt would not hold open. I tried a different Bolt latch, still would not work. Everything looked right, seem to function right.... except the bolt not holding. I started comparing everything, and then noticed when comparing the tension on the Bolt latch versus my other lowers, it was very stiff. I pulled the spring and it looked right, same as my others, but I noticed it was much much more stiff in comparison. Once I swapped the bolt latch spring it finally worked.
Link Posted: 9/12/2010 11:26:58 AM EDT
[Last Edit: 9/12/2010 11:43:44 AM EDT by H53EXPERT]
Why is it so hard for you to diagnose the problem?

Hold the bolt back and depress the lever, let the bolt go forward and observe the interface between the bolt lugs and the bolt catch.

Just by looking at your pictures, as worthless as most of them are for anyone to actually observe what is actually happening, and comparing to my rifles, it appears that your bolt catch was either machined to an improper dimension or someone tried reducing the profile for whatever reason and cut it down too much. That means the catch is not tall enough to block the bolt lugs, and the bolt just rides over the top of the catch.

Another thing to note, is that your bolt catch does not appear to be actuated to the up, or block, position by the magazine being in place. That most likely means that someone placed something underneath the catch that shouldn't be there. Or that the small well that is supposed to give the lever room to cant a little was not milled deep enough. By looking at the pictures that is what appears to be the problem. However, if the lever does actuate, even though the pictures are not showing as such, it has to be the height of the catch being wrong. I have some pictures to follow to better explain what I am saying.
Link Posted: 9/12/2010 11:52:39 AM EDT
Question #1. Does my lever actuate?





Question #2. If it does actuates, does it interfere with the bolt?



Question #3. If not, is it because the lug is too short?



Question #1A. If my lever does not actuate, why not?
At this point there are only so many possibilities. The back side of the lever was not made correctly, so there is no space for it to tilt. The well on the side where the lever is supposed to tilt into, when you push the lever, is not machined correctly so you can't depress the lever. The hole on the catch, where the roll pin goes through it too small, and doesn't allow the lever to pivot because of the tight fit. The roll pin is the wrong roll pin, and it is causing the same effect.

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