BCG will not lock back when bumped.

[Bearcatrp]

Have had this 12.5 inch 308 for a good 6 years. Put a AR Gold trigger in it. Sat in the safe for over a year. Brought it back out this year. Started slam firing. Replaced the trigger with the original trigger. Still doing it. Is it the spring thats weak that locks the bolt back or something else? Even when I lock the bolt back, the slightest bump will let loose the BCG. Am assuming its the spring but thought I would post this in case I am missing something. Its a Aero lower and a KAK upper. Appreciate your replies.

[hard h2o]

What condition is the firing pin in? Is it able to slide freely withing the bolt?

[Bearcatrp]

Sorry for the misleading headline. I changed it. When I lock the BCG back to leave the chamber open, the slightest bump unlocks it and closes the chamber. Will be taking it apart in the near future to see if any parts are worn or the spring is bad. Thought I would ask to see if there is another area I should be looking at. Thanks

[Rip Van Winkle]

Check the bolt catch for abnormal wear, and make sure there's no debris under it keeping it from fully engaging. You can visually inspect engagement by looking in the breach.

[Bearcatrp]

Here are some images to help diagnose this AR. The BCG is from KAK Industries.

[Rip Van Winkle]

I don't have a 308 based AR to compare it to, but it looks like there's not as much engagement as my M-forgery. Can you get more engagement by pushing on the latch?

Question: When you say it closes with a "tap", how much of a tap are we talking?

Here's a video of the M-Forgery.
[youtube=http://www.youtube.com/shorts/cTk_d9Z8KTw][/youtube]
https://www.youtube.com/shorts/cTk_d9Z8KTw

[nhluke]

Is it failing to stay open with or without an empty mag in? Have you tried other mags?

[Bearcatrp]

Was watching some utube videos yesterday. The pictures I saw showed the latch on 2 lugs, but on mine it shows only on one lug. Just a tiny bump will close the bolt. Even when moving it will cause it to close. I did try an empty 10 round mag which locks it back until a harder bump will close it. My plan for now is to replace the latch with one I have in my parts bin along with a different spring. Not sure if my SFAR in 308 is a standard BCG to try swapping but plan on checking that too. One thing to note. This is a AERO lower. The take down pins from a regular 308 parts kit were to short. Had to buy a AERO parts kit to make it fit properly. May contact AERO to see if there’s are a bit different too.

[Bearcatrp]

Posting pictures of 2 types of latches. The larger one was already installed. The smaller one is probably for AR15's but tried it anyways. Was worst. Sent Aero Precision a email to see if there lower requires a latch from them since this is a Aero lower. Am also starting to think its possibly the bolt itself.