Rock Island Armory 1911 A2 .40 S&W or 10mm 16 RD P16 OEMP164015B



Armscor ACT-MAG for the Para Ordnance P16, Rock Island Armory 1911 A2 .40 S&W or 10mm 16 RD or METRO ARMS 3011 SSD S&W 40 S&W magazine (P16B-40-16) Armscor OEMP164015B. This is the factory OEM magazine in the double stack Rock Island Armory 1911 A2 .40 S&W and 10mm with the 16 round magazine. This magazine is compatible in the 16 round Rock Island Armory M1911 A-2 10mm. 

The magazine is 4.675 in length.


The magazines have the standard flat base plate. They can be used with the Springer Precision extended base (must use with the Springer Precision locking plate).

NOT COMPATIBLE IN SOME OF THE PARA P16.40 WITHOUT MODIFICATIONS. I have been told it works in the Para Ordnance 16.40 LDA with no modification.  It will work in the Para P16.40 Pro Custom WITH SLIGHT MODIFICATIONS. This is what  customers told me they did to make them work in the Para P16.40:

Yesterday my magazines arrived and to my disappointment they didn't fit. I could see that they were shorter but not by much. The first thing I did was take off the ACT base plate and put on the stock pro custom base plate. After doing this they were very close to fitting, but still did not fit. I came to a crossroads where I had to decide if I was going to send them back or make them fit. I am an experienced woodworker but I have very little experience with metal. I packaged the magazines back up and was ready to send them back. I started thinking, ... if I screw one up oh well.

I took the magazine catch out of the gun and inserted the ACT-Mag with Para base plate and saw that the mag catch hole in the magazine was slightly off. I grabbed some sandpaper and a set of small files and slowly started opening the mag catch hole little by little. After about 30 minutes of filing a little and checking I had a magazine that locked in place. I slowly started to polish up my marks all the wall to 1000 grit sandpaper. I ended up widening the mag catch hole towards the top of the magazine by .0310 of an inch. The stock ACT-MAG magazine has an opening of 0.1345 inches I widened it to .1655 inches.

So here is the breakdown: The ACT-Mag base plates must be moved over to your stock pro custom magazines. The stock pro custom baseplates need to be moved to the ACT-Mag. Leave the spring and followers in their positions. The new magazines sit slightly and I mean slightly lower. I have been feeding practice rounds through them and I will be honest they feed better than the stock mags, nice and smooth. So if you buy (2) magazines and you have (2) stock pro custom magazines you will end up with (4) functional magazines. Based on my measurements you should be able to order Dawson Precision baseplates and have them fit.

This is from a customer with a Para P16-40 limited no magwell (built in 2011):

For the "Limited" model it works without any magazine modifications. The mag release may need to be replaced if it fits too loose. I say "may" because when I tried the mag in my Black ops it stayed locked with the stock mag release. The stock mag release has a small tab and the Act-Mag kept falling out (in the Para P16-40 limited no magwell built in 2011). Once I replaced the mag release with the Guncraft aftermarket release with the larger tab, it stayed locked and secure.


  • Model: (P16B-40-16) Armscor OEMP164015B
  • Manufactured by: Armscor - Rock Island Armory

Scott Taylor
5 of 5 Stars
Quick shipping and perfect fit for my RIA 51782. Used Dawson base pads and Arredondo spring & follower for 20 rounds as well. Works like a champ with the factory magazine well. Highly recommended!
Paul Snow
5 of 5 Stars
My first purchase from Greg was great, supper fast shipping. I purchased these for the RIA #52009, 1911 A2 10mm, they function as good as the mag that came with it, plus you get 16+1, instead of 15+1.
James Morrison
5 of 5 Stars
Great service. These fit and feed better than the manufacturer mags. Super fast shipping. Thanx.
James Byerly
5 of 5 Stars
Shipped fast! And if you have ANY questions Greg will respond promptly. I bought one not sure if it would work in my 2011 10mm double stack. Its the same mag as stock. I'm ordering 2 or 3 now. They average out able $27 each shipped and the more you buy its cheaper. And good regular 1911 mags cost more! Thanks Greg!
Barry Uze
5 of 5 Stars
Purchased two of these for my Rock Island Tactical II 10mm (52009). They fit perfectly. I ordered these on a Friday and they were at my house on Monday. Great service.
David Brown
5 of 5 Stars
First purchase from Greg Cote, LLC and I am impressed. Shipping is really fast; order placed Wednesday morning was received Friday. Additional info on mags supplied by GC in the description was the reason I made the purchase. I can confirm these mags work flawlessly in the Rock Island Armory 10mm double stack 1911.