I recently purchased a couple of 20 round magazines from a local gunshop.  They had Brownell's labels on the package with stock #687-015-020.  They have a steel body with polished, black oxide finish made by S.L. SMITH & ASSOCIATES, INC.  They feed ok, except sometimes the bolt won't fully feed the first round out of the mag and the last round never feeds properly.  The bolt is always held back with the last round hanging loose in the receiver.  I was wondering if anyone else has had these problems with this particular manufactures product and if there is anything I could do to get these mags working properly.  I also have 2 USGI mags that function perfectly, so I don't think it is the rifle, or atleast I hope it isn't.  Any help I could get would be greatly appreciated.  I am new to AR-15.com, as I have just purchased a DPMS a few weeks ago, and am greatly impressed with the amount of knowledge that I have gained from you guys since joining.

I don't know, as I dont have any 20rd GI mags to compare them too,  I only have 30rd ones.

Just FYI USGI 20 is 4.5 inches at the front 4 inches at the back .

Thanks Kodiak-AK,
I measured them and they are about a 1/4 inch longer on each side, does this mean they may be Promags?  And if so, is this a common problem with these mags and is there any thing I can do to make em feed properly?

I've got the same problem but with a different brand of 20 rd mags.
The mags are some old Colts with the following stamp on the baseplate:
COLT AR-15
CAL. 5.56 MM
COLT'S PT. F.A. MFG. CO. INC.
HARTFORD, CONN. U.S.A.

Also, if I happen to load just one round, it comes loose from under the mag lip and falls loose into the receiver. What's going on?

Brownells mags are a hit and a miss. I purchased three of their 30rd mag bodies. One worked perfectly, one I sold NIW, and one had excessive flashing on the inside welds that was stopping the follower from feeding properly. Im still trying to get that one to work correctly. Good luck.

PS- From what I have heard, Brownells sells the same mag bodies as CMMG.

Quoted: Thanks Kodiak-AK, I measured them and they are about a 1/4 inch longer on each side, does this mean they may be Promags?  And if so, is this a common problem with these mags and is there any thing I can do to make em feed properly?

I'm sorry . I have no clue . The only Non USGI mags I have are Orlites.


gkkuo

Those are the same marks as my USGI 20's . Have your feed lips spread at all maybe?

Quoted: Quoted: Thanks Kodiak-AK, I measured them and they are about a 1/4 inch longer on each side, does this mean they may be Promags?  And if so, is this a common problem with these mags and is there any thing I can do to make em feed properly? I'm sorry . I have no clue . The only Non USGI mags I have are Orlites. gkkuo Those are the same marks as my USGI 20's . Have your feed lips spread at all maybe?

Now that I carefully examined those mags, I'm fairly sure that I need to change out the followers. When there's a single round in the mags, the follower tilts. The round isn't seat correctly under the feed lips. So when I put the mag into the well, the round jars loose.

billy_dynamite,
I would first request a refund from the shop where you purchased them.  If that does not work, contact Brownells.