Should Ar Magazines Drop Free?

[eightshot627]

I just finished my first AR build. Should the magazines drop free from the mag well when the release is pushed? Or do I have more work to do?

Thanks,

Walt

[n2ipsc]

I just finished my first AR build. Should the magazines drop free from the mag well when the release is pushed? Or do I have more work to do?

Thanks,

Walt

Ideally, yes. A search will turn up many threads on fitting mag catches and the proper "fit" of mags in your AR (such as THIS and THIS). In short, the consensus seems to be that any quality mag should seat with some very slight but noticeable "slop," and (thus) drop free.

You'll likely find that different mfgrs' mags will behave differently (you don't mention which receiver you used, but this can play a part as well - some are tighter than others...). By way of example, I've a few mags that require a bit of a pull to remove. This isn't necessarily a bad thing - I use them for the primary load when I've clamped a pair together for a mid-COF reload - keeps them from "getting away from me," if you will. Everything else I expect to rocket out of the gun when the release is pushed...

The worst offenders I've found are the 40-round steel units, which seem to have the sloppiest tolerances. Quite often these won't begin to drop free, and, sadly, it usually takes buying (and discarding) several to find one or two that will drop reliably. YMMV.

Be aware, too, that curved high-cap units that rocket out of the gun when held vertically can bind with the slightest inclination of the rifle. I had a couple of 40's that were driving me nuts until it dawned on me that I was elevating the muzzle ever so slightly when I hit the release, and inducing just enough drag to where partially-discharged mags would not drop.

Edited September 6, 2006 by n2ipsc

[George]

Yes they should, but a lot do not. Lotsa' reasons.

Mag bodies on metal ones can be outa' square and need squeezing/peening back to square.

Mags can be oversize like the later Thermolds are, or the mag well can be undersize and need some metal removed.

GI 20's should always drop free and if they don't this would probably indicate a too small mag well.

I wound up squeezing in a vice and using a ball peen hammer on some older Sanchez USGI's to get them to drop free. I also wound up hoggin' out the magwell on one AR with a Dremel to get the later Thermolds to drop free.

Do a lot of measuring and inspecting first before you start removing metal from anything. Sometimes the issue is as small as a burr on a weld seam of one mag.

I won't put up with mags that won't drop free and I also won't put up with AR's that require tapping a mag into place to seat it. Neither should be happening.

[.40AET]

I just finished my first AR build.

I had the same problem. Unscrew the mag catch one turn and try all of the mags again.

[lynn jones]

i'm sure "magpul" people would say no!

lynn

[George]

I have Magpul's on all of my 30 round AR mags, but they are only there for protecting the bottom plates when I monopod, not for "pullin" the mags outa' wells ;-)

[eightshot627]

Thanks for your responces.

DROP FREE! Back to the work bench.

RRA Lower (after more reading they have tight wells), every thing else is DPMS, JP and Clark.

I checked the mag catch before posting.

New lower, new mags, I think my best bet now is to take it to the range and scrape the "NEW" off. Then hit the workbench.

Thanks,

Walt

[Paule]

Sometimes the mag catch itself is the problem. If mags drop free from the lower without the upper installed, but have issues when assembled, mag catch may be a little high. Geometry tolerances in AR specs are pretty wide and still "in spec". Sometimes just a little off the top shelf of the catch works wonders.

[Brazos]

Sometimes the mag catch itself is the problem. If mags drop free from the lower without the upper installed, but have issues when assembled, mag catch may be a little high. Geometry tolerances in AR specs are pretty wide and still "in spec". Sometimes just a little off the top shelf of the catch works wonders.

I discovered an interestingbit of info about this a while back...my comp rifle lower is a Bushmaster, all my other lowers are DPMS. I had purchased some older mags and some would not drop from my Bushy but would drop from all the DPMS.

After much inspection it bacme clear that the large Bushmaster logo stamping was the issue. It pressed into the side of the mag well over such a large area that it was causing the mags to bind in the well. Sanding helped a bit...but know I just use mags that will drop out of that lower.

B