Sig Sauer AR Magazines

[tso]

Is anyone familiar with the Sig Sauer 223 polymer mags ?

 

[Doc Holliday]

They function fine in a Sig 556, but not in an AR...

 

[ulshop]

just wondering what the difference would be? never used a true sig mag, but ar mags work perfectly in my 556. (sipping more of the magpul kool-aid...)

 

[Doc Holliday]

I just went and pulled them out of the safe and did some testing...

Sig mag would only seat in my AR with the bolt locked back. When you try to release the bolt, it does nothing.

I took some photos comparing a Sig 556 mag & a MagPul PMag:

The Comparison:

MagPul PMag:

Sig 556:

 

[tso]

After a comparison with my other mags the rear opening seems to be the only real difference ... a couple minutes with a dremel tool, the results are on the right, an untouched mag on the left.

Magazine on the right now seats with the bolt closed, manually cycles the rounds and locks the bolt back on after the last round.

Range tomorrow ... will post results.