ASC Magazine fix?
- Thread starter cyclone
- Start date
I get this question a lot.
There are two main spots that need to be smoothed out for them to run 100%. The less important one is on the inside upper edge of the front of the magazine. This reduces the amount that this edge catches on the bullets and casings as they are fed. A simple way to know when you've filed enough is by slowly pushing the rounds out with your thumb; if the shelf where the bullet and case meet catches the lip and stops feeding, then you need to keep filing.
The more important spot is the inside of the curvature near the front of the feed lips. As the mags are formed, this area tends to become jagged and somewhat out of round when compared to the brass casings that ride across it. You need to take a small round needle file to the area. As the rounds feed, this area catches on the brass and sometimes the rim of the cases, deflecting the bullet tips up and outward from the midline, thus causing misfeeds.
This is a view of the jagged area before filing:
Testing to see if you've filed this portion enough is similar to the previous one. Push rounds out slowly, if you notice a scratch or gouge forming on the brass from that area, or if that area catches the case rim, you need to keep filing. Another thing to mention is you must keep that area round; if you square it off, or file it into an irregular shape, it still will not feed well.
----
As an aside, if you have issues loading your mags to 10 or inserting on a closed bolt, do not clip coils from the spring. The spring never reaches full compression or "solid height." The height of the legs of the follower is significantly greater than the solid height of the spring (approximately 10mm greater if you do the math). In order to increase to 10.5 round capacity, you will need to file your follower legs or replace them with aftermarket followers like Magpul, etc.
You can see the Magpul followers have the same leg length as the standard ones, but the thickness of the "tabletop" where the rounds sit is maybe 1mm less. By trimming the standard legs, you achieve the same effect.
There are two main spots that need to be smoothed out for them to run 100%. The less important one is on the inside upper edge of the front of the magazine. This reduces the amount that this edge catches on the bullets and casings as they are fed. A simple way to know when you've filed enough is by slowly pushing the rounds out with your thumb; if the shelf where the bullet and case meet catches the lip and stops feeding, then you need to keep filing.
The more important spot is the inside of the curvature near the front of the feed lips. As the mags are formed, this area tends to become jagged and somewhat out of round when compared to the brass casings that ride across it. You need to take a small round needle file to the area. As the rounds feed, this area catches on the brass and sometimes the rim of the cases, deflecting the bullet tips up and outward from the midline, thus causing misfeeds.
This is a view of the jagged area before filing:
Testing to see if you've filed this portion enough is similar to the previous one. Push rounds out slowly, if you notice a scratch or gouge forming on the brass from that area, or if that area catches the case rim, you need to keep filing. Another thing to mention is you must keep that area round; if you square it off, or file it into an irregular shape, it still will not feed well.
----
As an aside, if you have issues loading your mags to 10 or inserting on a closed bolt, do not clip coils from the spring. The spring never reaches full compression or "solid height." The height of the legs of the follower is significantly greater than the solid height of the spring (approximately 10mm greater if you do the math). In order to increase to 10.5 round capacity, you will need to file your follower legs or replace them with aftermarket followers like Magpul, etc.
You can see the Magpul followers have the same leg length as the standard ones, but the thickness of the "tabletop" where the rounds sit is maybe 1mm less. By trimming the standard legs, you achieve the same effect.
Last edited:
