450 MAGS - MY OPINION WHAT WORKS AND WHY

[MR 450BUSHMASTER]

I'm presenting my thoughts, along with some data and images to back them up, about what I've found to work when 'making' your own mags for the 450. There has been discussion on this forum and others but I have not seen any on this specific aspect. Forgive me if this is old news!

Based on recomendation from someone on this forum I picked up 3 of the single round inserts for the mags:
http://fulton-armory.com/magazinefollow ... astic.aspx
Three shipped cost $39.85

I had also read somewhere that the stainless 20 round mags would work great for the 450 so I picked up 3 of:
http://www.midwayusa.com/viewproduct/?p ... ber=132999
Three shipped cost $38.92

So for just shy of $80 I've got 3 new 450 mags... Wrong - and here's why!

After messing around with the mags and cycling rounds through the gun (not shooting just with swift pulls to the charging handle) it was obvious that the mags were not created equal. The opening (specifically where the round is held by the top of the mag) was narrower on the factory 450 mag from bushmaster I have as compared to the new AR Stoner mags. I checked three of the 30 round Brownells mags I've got and found them to be much closer to the factory bushmaster mag.

Here's the data (in inches) - I measured the back, middle, and front of the opening (that holds the case) and here's the results (in that order of measurement for each mag).

Factory mag .442, .456, .461
Brownells 1 .438, .447, .450
Brownells 2 .443, .447, .455
Brownells 3 .449, .453, .459
AS Stoner 1 .467, .491, .505
AR Stoner 2 .460, .485, .501
AR Stoner 3 .463, .492, .500

The round is .500 at base and .476 at 'neck' (image attached)

The difference is obvious. And reflect how the rounds feed. The AR Stoner mags with the wider opening don’t hold the round in place well enough and they feed horribly, and I scratched and dented the rounds constantly with this exercise. All three of the 30 round Brownells mags with the narrower opening fed great, and held 10 to 11 rounds easily.
I’ve attached a photo. From left to right you are looking at:

LEFT: factory mag MIDDLE: AR Stoner mag RIGHT: Brownells

In the middle photo you can see the blue follower piece in the AR Stoner mag. The first question that came to my mind was what the follower looked like? I tried putting the follower from the factory mag in the AR Stoner mag and it made no difference.

Now for your thoughts…

Bill

[dale]

check out the sig 556 mags. mine work flawlessly right out of the box.
i bought a 2-pack from the sig sauer website, 2 more for $20 at a gun show.
they hold 12 tight, 11 easily.

[gunnut]

The Sig 5.56 mags Do work work right out of the box, no mods. Full auto tested Hold 12rds. I load 10.
throw away the coupler, good for about 3 rds.

[Texas Sheepdawg]

Yeah, the sig mags work great. Got a pair myself.
I don't remember any data on Stoner mags. But it's
good to hear the Brownells feed ramps are usable.
With the right followers, that might be another way to
go.

[Jeepejeep]

ARGGGG all this is killing me! I can't get those mags here because of the moronic high cap mag ban in NYS. DAMMIT I have to move and soon!

[Texas Sheepdawg]

ARGGGG all this is killing me! I can't get those mags here because of the moronic high cap mag ban in NYS. DAMMIT I have to move and soon!

Housing and jobs are good here in the DFW area in Texas.
And the hogs are so plentiful, they have Ted Nugent machine gunning
Them from a helicopter.

[Jeepejeep]

Texas is one state I think I'd like but my wife will not move that far away from family in NY. I think I'lll wind up in PA possibly Va. Not great but better than friggin' NY.

[gunnuttwo]

I got a pair of the Sig Sauer 5.56 Polymer 30-round magazines. I am very dissatisfied with them! Everyone else on this site says that they work good, but not for me. The lips look like they were trimmed by someone inexperienced as they are uneven, at an angle, curved, BUT not upside down! I contacted the company and the representative just spaced me off.
From your (Mr 450Bushmaster) assessment of the magazines, I can see how they are different. I don't have any way of measuring the lips, but by loading the magazines and comparing them, I can see quite a difference. The feed lips on the Sig mags hold the bullet lower and flatter than the factory magazine. I think I will take the time to trim the lips up to match the factory magazine and see if they work any better.

Gunnut: I don't understand what you mean by the statement: "throw away the coupler, good for about 3 rds." How does the coupler change the number of rounds that the magazine will hold?

Thank you everyone for your comments and feedback, that is what makes this such a great place to hang out!

[Shootist]

The magazine coupler will break from the recoil.

[gunnut]

The sig 5.56 mag coupler will not hold the 2 mags together when fully loaded with 450B ammo for more then 3 shots fired.