Accurate Mag scratching brass

[demolitionman]

I just built a Mcrees chassis rifle using an Accurate Mag .308 length magazine for my .243 rounds. The mag is a centerfeed. Its scratching the hell out of my brass leaviny big cuts lengthwise where the mag lips touch the brass. Dumb question, would a staggerfeed mag work as well and also is bending out thr mag lips on this centerfeed mag a good way to adjust the mag so it doesnt damage my brass so much? Thank you.

 

[wareagle700]

The scratches arent pretty but won't hurt anyhting. I wouldn't bend the feedlips any. You can take some 800 grit sandpaper and smooth up the rough edges inside the feed lips and it will help.

 

[demolitionman]

Thank you Wareagle. Do any poly mags fit the G7 Mcree's Chassis?

 

[tacticalpanda]

Does this happen on every mag or just one?

What action is it? I thought I had this problem. Then I thought a burr in my chamber. Turns out it's my action and is a pretty common thing. Scratch comes from the race way. Never affected anything and after tumbling can hardly notice.

 

[Threadcutter308]

The scratches arent pretty but won't hurt anyhting. I wouldn't bend the feedlips any. You can take some 800 grit sandpaper and smooth up the rough edges inside the feed lips and it will help.

Agreed, don't bend the feed lips. If you have a Dremel, you can buy some "Cratex" tips and try that too......I'm sure that 800 grit would work just fine as well.

 

[chadrp]

I had the same issue of my accurate mag scratching really badly also when I went to the aics mags from ctr mags. It also seemed harder to work the bolt from the mag "biting" the brass.

After comparing the 2 different mags I noticed looking from the nose of the round, the ctr mag lips were longer, allowed less exposed round, and basically held the round below the flat length of the lips.

With the accurate mag lips being shorter, it allowed the round to sit higher, and held it more by the edge of the lips causing the deep scratching.

I took the mag apart and took a file at about the same angle as the round contacted the lip edge and filed that bottom corner edge that runs the length of the lip off on both sides. This gave it a more tapered thickness instead of a sharp squared eged and more surface contact on the under side of the lip for the round to ride instead of sharp edge the round rode on before. I also filed the inside front curve of the mag a little also as the round lifts up coming out of the mag.

Now there is hardly any scratching and the round strips easier and smoother.


I hope this helps and makes sense with out a picture.

 

[demolitionman]

I had the same issue of my accurate mag scratching really badly also when I went to the aics mags from ctr mags. It also seemed harder to work the bolt from the mag "biting" the brass.

After comparing the 2 different mags I noticed looking from the nose of the round, the ctr mag lips were longer, allowed less exposed round, and basically held the round below the flat length of the lips.

With the accurate mag lips being shorter, it allowed the round to sit higher, and held it more by the edge of the lips causing the deep scratching.

I took the mag apart and took a file at about the same angle as the round contacted the lip edge and filed that bottom corner edge that runs the length of the lip off on both sides. This gave it a more tapered thickness instead of a sharp squared eged and more surface contact on the under side of the lip for the round to ride instead of sharp edge the round rode on before. I also filed the inside front curve of the mag a little also as the round lifts up coming out of the mag.

Now there is hardly any scratching and the round strips easier and smoother.


I hope this helps and makes sense with out a picture.

Chad, that makes perfect sense. You have described exactly what I have going on. The scratching is severe, as in almost gouges my brass. I'm not OCD by any means but the marks I'm getting from the mag lips on my brass is pretty serious and I was planning on running Lapua at some point and wanted to fix the issue now before I make that switch. I've been really busy since I posted this and haven't had a chance to look into the issue closer. I will post up when I figure out if I can fix the scratching/gouging issue.

Also, to those who mentioned the chamber walls causing the brass scratching: its not the chamber. I fired this rifle for hundreds of rounds with an internal box mag with zero marks on my brass.

ONE MORE QUESTION; do any POLY mags work well in these Mcrees G7 chassis?

 

[chadrp]

Chad, that makes perfect sense. You have described exactly what I have going on. The scratching is severe, as in almost gouges my brass. I'm not OCD by any means but the marks I'm getting from the mag lips on my brass is pretty serious and I was planning on running Lapua at some point and wanted to fix the issue now before I make that switch. I've been really busy since I posted this and haven't had a chance to look into the issue closer. I will post up when I figure out if I can fix the scratching/gouging issue.

Also, to those who mentioned the chamber walls causing the brass scratching: its not the chamber. I fired this rifle for hundreds of rounds with an internal box mag with zero marks on my brass.

ONE MORE QUESTION; do any POLY mags work well in these Mcrees G7 chassis?

Glad it made sense. I really need to set up an account for pics, as it would have been easier to draw what I did lol.

I don't reload, yet atleast, but i do keep the brass in case and mine were severely gouged like yours, and didnt like the stiffer feed because of it so it was win win. Also the accurate spring has way more pressure than the ctr mags so I thought about shortening it to help but after the filing and a little fine sand paper to polish what was filed I was happy with it.

 

[Paulyr450]

Agreed, don't bend the feed lips. If you have a Dremel, you can buy some "Cratex" tips and try that too......I'm sure that 800 grit would work just fine as well.

I did this exact same thing with my accurate mags.

 

[5RWill]

The scratches arent pretty but won't hurt anyhting. I wouldn't bend the feedlips any. You can take some 800 grit sandpaper and smooth up the rough edges inside the feed lips and it will help.

I did the same with sand paper on all my AI mags. Haven't worried about it with my AW despite the scratches.

 

[demolitionman]

I hit the feed lips with 180, then some 800, then finished off with some 1500. That's just what i had and it did the trick. Brass chambers easier now and i have very veey minimal scratching. Working the 1500grit paper nearly polished it perfectly smooth. Im very happy with the results. Thanks for the tips.


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