Do AICS mags need to 'break in'?

SRSDriver

Sergeant
Full Member
Minuteman
Aug 10, 2011
551
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Northern CO
I'm using an XLR chassis, and have absolutly zero problems with my 140g hybrid load and my 5 round aics mags, but I end up with some binding/feed issues with the same round in the 10 rounders.

1) Do these need to 'break in'?

2) Should I just drill/weld the 10 rounders to remove the front plate and extend the length? I'd rather not play with the jump, they are shooting for me now.
 
I've experienced the same. Might help to clarify what cartridge and OAL rather than bullet weight, but I don't think it is uncommon.
10th (or first round) being more difficult to chamber than the rest of the mag.
 
my new 10 rounders took a few magazines worth to break in and feed reliably. The feed lips also need to get worn down, as they're scratching up the brass pretty good on chambering. You should be fine, just go shoot some.
 
I am curious to know outcome. I am experiencing same or simliar issue with 338 LM feeding BUT I assume it is due to lips needing tweaking. I have yet to tweak lips as I have not finalize LD with two other bullets and powders. I figured once completed al I would have to do it tweak lips and be done.

FWIW, as it stands right now (OAL at 3.630" of 3.650 max interior mag length) appears cartridge is released too soon into action causing a slight jerk needed to feed round into chamber.
 
I've experienced the same. Might help to clarify what cartridge and OAL rather than bullet weight, but I don't think it is uncommon.
10th (or first round) being more difficult to chamber than the rest of the mag.

Same here.
First couple are rough and then they smooth out.
Five-round mags are all smooth as butter in the same actions.
 
My AICS .308 mags are loaded to just under max OAL and I'm having a tiny bit of binding, but it seems to be the feed lips rather than the bullet grabbing the front of the mag. The lips are extremely tight and scratching up the brass pretty good. I've only run about 60 rounds through them, so I'll see if they loosen up next time I go out.