Colt M16 Mag Questions/Problems

[.45&TKD]

I bought 10 Colt 30 round M-16 mags at a gun show today.

2 Questions:

1) The mags were "new" but discounted because they had 2 holes towards the bottom for water drainage. Apparently, they were made for special op situations (seals) where water is a factor. I paid $190 for 10 mags. There were the same mags for sale without the drain holes for $30 each with no quantity discount. I figured I could always tape over the holes to keep dirt out, if need be.

Q: Has anyone ever seen or heard of mags with drain holes before?

2) Regarding fit: When I got home, 7 out of 10 mags fit perfectly in my Bushmaster AR-15. 2 mags were a tight fit, meaning they did not drop out when I engaged the mag release, but needed to be lightly pulled out. And one of them was so tight that I could barely force it on and out. My only experience with AR mags is with 4 Thermold mags that fit and work perfectly in my Bushmaster.

Q: Is is common for there to be this much variation in fit with metal AR mags, or with Colt AR mags in particular?

The gun show will still be here tomorrow and I thinking of bringing the bad ones back.

 

[444]

Who manufacturered the magazines ?

It should be stamped on the floorplate.

Check out this link. It may give you some food for thought.
http://www.biggerhammer.net/ar15/magazines/

 

[.45&TKD]

"Who manufacturered the magazines ?

It should be stamped on the floorplate."

They are Colt mags.

 

[444]

I haven't encountered that kind of variation in AR15 magazines. I don't think I have ever had one that didn't want to insert into the magwell and I have owned perhaps a hundred not counting the ones I used in the Army. I have had ones that didn't want to lock in, but they went in the mag well fine.
As you will see on that link, Colt mags were made by OKAY and are good mags. If they don't work in your gun, I would take them back, at least the ones that don't work. I have also not seem much variation in guns. Bushmasters are made to mil-spec, I can almost guarentee it isn't anything to do with your rifle.
I wonder if the mags have been refinished and have too much paint on them ?

 

[.45&TKD]

I don't think it is the paint.

So it is unusual for the mag to not fall out when the mag release is appiled?

 

[Badger Arms]

New often means refinished in some crooks' definition. There are a few things you can do. Bushmaster has historically had tighter magazine wells. Their mag wells are not mil-spec in that regard. Still, most magazines will fit. Some, you will have to 'tweak.' The way I do this is first find out where they are rubbing. To do this, I use sharpie or some sort of marker to 'color the top of the magazine. Insert the mags that are tight and then remove them, you will notice where they are rubbing.

Often, this is in the rear of the magazine. To correct this, squeeze just that end in a vice slowly. Take it out after you squeeze a little and test it. If it needs more, reinsert in vice and squeeze a bit more. Take your time, if you squeeze too hard, you will pop the weld in the back and that's not good.

If the mag rubs in the center, take two pencils and lay them alongside the marks and squeeze the pencils against the magazine in a vice. Should be able to do this the same way as I suggested above.

Now, if the magazine rubs on the front and back (meaning it's too deep) you can squeeze the magazine lengthwise but this will invariably bulge the magazine out meaning you might have to do the pencil squeeze.

One place I've never seen magazines too wide was in the front. If they are factory mags, the front is the sturdiest part of the mag and you are unlikely to have them too wide there. Good luck.

 

[444]

Just take them back. I presently own 6 bushmasters and have never had a problem with any magazine. I presently own various USGI mags, Thermolds, and Orolites. I have somewhere in the neighborhood of 50 magazines at present. They all worked fine in all my rifles (Bushmaster, Colt, and Oly). What you describe is abnormal to me, but appearently happens, but I wouldn't bend anything, I would take them back.

 

[TechBrute]

More resources:

http://magfaq.tripod.com/
http://www.ar15.com/forums/forum.html?b=3&f=17

 

[BDM]

TO BADGER ARMS if the bushmaster was not to spec the military wouldnt have accepted the first made M4s by bushmaster back in 91 the magwell was not flared enough to accomadate older made orlite mags but will take evry other mag including newer orlites they flare the wells better now I have a pre and post ban you can see the difference but they are not out of "spec" it was olympic arms with tight out of spec magwells and hammer/trigger pin holes not drilled in the right spots. Bushmaster is the only company making 1 grade of weapon you want to talk out of spec colts removable carry handle is taller than spec and bushmaster makes a modified site to compliment this,as far as colt mags they have 9 weld marks front and back and back in the day most manufacturewrs mags were made by labelle just like parsons,adventureline,and ok were all the same manufacturing plant with 3 different companies same tooling .labelle also made for bushmaster and colt colt just specifies 9 welds.

 

[curt]

The "special forces tactical drain holes" were probably nothing more than holes someone drilled to use para cord for retrieving the mags for pouches.

Just cause the mags have Colt floorplates doesn't mean they are Colts. They could be crappy USA mags that someone put colt floorplates on.

Its likely that the ones that you are having trouble with aren't GI. They shouldn't be painted unless someone was trying to purty them up or they were crappy non-anodized mags. BTW $19 isn't that great a deal for used mags so don't feel guilty about getting your money back.

 

[Badger Arms]

TO BADGER ARMS if the bushmaster was not to spec the military wouldnt have accepted the first made M4s by bushmaster back in 91 the magwell was not flared enough to accomadate older made orlite mags but will take evry other mag including newer orlites they flare the wells better now I have a pre and post ban you can see the difference but they are not out of "spec" it was olympic arms with tight out of spec magwells and hammer/trigger pin holes not drilled in the right spots.

BDM: Bushmasters WERE out of spec. The M-4 carbine is one product they make with new forgings. As late as September 12th of 1994 when I received my pre-ban receiver and assembled into an assault rifle, I COULD NOT INSERT AN ORELITE magazine. Bushmaster's I have bought since then have been hit-and-miss. Per the TDP (technical data package) drawings, they are still out-of-spec. Despite this, if the magazine is within the TDP specifications, it will fit and function in Bushmasters save for the Orelite magazines. The mags he bought were likely surplused because the lips were expanded too much. The fact is, the person who sold them sold them as surplus magazines that worked. A little tweaking will bring them back into specifications and everybody will be happy. IIRC, specifications call for a mag-well of .898" diamater in the rear end. I'm going by memory, but magazines are supposed to be no greater than .890 diamater at this point. All the magazine has to do is expand .009". That's very little. Dropping a full magazine on a hard surface will do this. Measuring my AR-15 mag wells, I got the following results:

Bushmaster pre-Ban: .902"
Bushy post-Ban: .900"
DPMS Post-Ban:" .900"
Oympic post-Ban's: .898", .902"

Every single one of my magazines fit into the minimum-spec Oly receiver. I checked a handful of magazines and all measured .890" or slightly smaller. Forgot to add, about 10 of my pre-ban mags required either the pencil or the vice-to-the-rear treatment. These are the only magazines I use and they are just as reliable as they can be... 100% feed with no magazine-related malfunctions.

 

[BDM]

Bought my preban new in 93 the magwell dimensions are the same between then both the post ban is only 7 months old so maybe you just got a lemon as far as new forgings why would old or new forgings matter as long as they are machined the right way my rifles are 10 years apart and the dimensions of the magwell are the same the post ban is just flared on a steeper angle so if this were true measurements would be different it could be you got a poor machined one maybe less care was taken cause it was just a receiver all I know is my factory carbines dimensions is the same as the post ban just the post ban is finished better but thats the only difference Im sure if you sent them back the receiver they could take care of it im sure its easier to open up a magwell than one thats been broached to wide.