[MAJORMINUS]

I have noticed that the top cartridge case is getting dented in a 20 rnd. mag that I like to use.It appears that the bolt is denting the case right behind the shoulder of the case.I am not having any feed/extraction problems, but I would like to eliminate this problem if possible.I have not noticed it with my factory 5 rnd or any of my 30 rnd mags.Any suggestions on a fix would be appreciated.

 

[va hunter]

Mine does this too I am going to try different gas bushing from Mikes IN OREGON.excuse spelling

 

[cajungeo]

Welcome to the forum Major. If you check the sliderod assy, about 1 3/4" in front of your finger handle there will be brass colored stains. This is where the case is getting dented, not the bolt. Mine used to get some heavy dents where you described, and on the case mouths. After replacing the std gas port with a smaller one this reduced the ejection velocity so there isn't the heavy impact with the cases. I cannot explain why it ONLY occurs with your favorite mag.

 

[MAJORMINUS]

Thats a negative on getting dented during ejection. The deformation is taking place before firing. I compared the mag in question to a Ruger mag and the lips are higher than the factory mag.The bolt is denting the case when the top round is on the left stack. I did a little bending on the lips and the result has been a less severe dent on the case.I want to add that I almost FUBARed the mag by bending the lips with needle-nose pliars and I am not happy with the job. I have seen the little dings caused by the ejected case striking the charging handle/slide , but the deformation caused by the bolt is more severe.I do not know the manufacture that produce this 20 rnd mag, but none of my 30 rnd or 5 rnd mags have this problem . I don't like the 5 or 30 rnd mag when using my Mini for hunting, so it looks like I will have to come of a little $$ for a new 10 or 20 rnd mag.

 

[cajungeo]

Sounds like you have it nailed down. I like duck bill plyers over needle nose plyers, as it dosen't leave the waivy little dents. I also wrap the jaws with a couple wraps of masking tape. Being in aircraft, we cannot bend parts, we "reform" them, and do not leave tool marks. A pair of calipers for measuring gaps etc. may come in handy.

To identify your mag visit our mag. gallery. It has most all mags, and views to Id most mags. You then can do a search to get a general consensus on the function of that brand.