3rd Gen Custom RIA A2 HC 10mm / .40 S&W 10 Round Magazine
Click To Enlarge

These are high quality, high reliability magazines for Armscor Rock Island Armory (RIA) High Capacity 2011-style 10mm and .40 S&W pistols.  Specfically, these are for the A2 HC pistols that use the 16 round double stack magazines and are designed for smooth reliable feeding. They are not for the traditional 8-round 1911 pistols (I would recommend Wilson Combat or Tripp Cobras if you have one of those pistols and lots of websites carry one or the other).

Due to the modifications, these are compatible with Para Ordnance or "Para" style P16 magazines.  If you have a pistol that uses Para style magazines, these should work with them.  I would recommend searching the web to confirm if Para style mags work directly in your pistol or require modification. The mag lips are short so the round is not fully supported - RIA pistols do not require that for example.  If your model of pistol requires the cartridge to be fully supported, these will not work.

These magazines have a block inserted to limit the capacity to 10 rounds and the base plate is permanently riveted in place.  This is done for folks in regulated areas with this round limit.

These magazines are custom made by starting with Mec-Gar P14-45 magazine tubes and we then modify the feed lips to properly retain and feed 10mm rounds.  Note, a normal P14 mag can’t securely retain a 10mm round because a .45 ACP case diameter is 0.4734" while 10mm measures 10.8mm (0.425") and .40 S&W measures 10.77mm (0.424").  What you tend to find is that a 10mm cartridge, which is what I shoot, can sit in a .45 ACP mag but it will pull out or even fall out of the magazine far too easily.  The feed lips must be adjusted to properly retain the 10mm & .40 S&W cartridges, which is exactly what we do.

These hand-tuned mags will only work with 10mm and .40 S&W.  They will no longer feed .45 ACP correctly - just 10mm and .40.  Mec-Gar stamps "P14-.45" on them and I do not have a way to change that.  

I am getting a couple of emails each day asking if I really have these magazines -- Yes, I really have these on-hand.

I recently wrote a blog post about why I think our mags are the best for the double stack 10mm & .40 S&W RIA pistols - click here - it has a lot of photos so you can see one of our mags next to an OEM mag.

These custom mags should work with Armscor RIA pistols that use the OEMP164015B FS A2 double stack magazine.  The RIA pistols that use these mags iinclude:

  • 56862 TAC Ultra Threaded 10mm
  • 52000 PRO Match Ultra 6" HC 10mm
  • 52009 Rock Ultra FS HC 10mm
  • 51738 Pro Match Ultra H - 40S&W - note, I tune for 10mm as I don't have a .40 so some minor adjustments might be needed.

The adjustment process and tooling took some work because Mec-Gar uses surprisingly resilient hardened steel magazine bodies and feed lips.  I had to develop a specialized jig and process to bend the feedlips to properly retain and feed 10mm rounds to the ramped supported barrel that RIA uses in the above pistols.

Again, why buy our magazines?

  • Mec-Gar's quality is superb so we start with an excellent foundation to build on
  • They have hardened steel bodies and feed lips will hold up very well with extreme use
  • Mec-Gar developed a remarkable anti-friction coating that aids in feeding and even makes loading the magazine easier
  • The magazine spring is made from type “D” music wire and holds up nicely - I think it is far better than the original Para or RIA springs.
  • The polymer base plate that fits very nicely in the large RIA mag well funnels.  
  • The floor and baseplates lock into place and can't be knocked off easily as can happen with some of the "toolless" designs.
  • The slightly taller magazine body clears the RIA mag-well funnel very easily.  It’s longer than our previous generations of magazines and is even slightly longer than the original RIA/Act-Mag magazine
  • The magazine’s specified capacity is 16 rounds of 10mm.  It’s a tight fit but I can often fit 17 rounds in there but I can’t guarantee it.

One small detail, since these were originally for .45 rounds, the mag round indicator count doesn’t match since you will be loading either 10mm or .40 – usually you have one or two more rounds of 10mm/.40 compared to what the round count hole label says.

A fellow asked if I had made many magazines for the RIA pistols and I told him I have made and sold well over 700 at this point.  


After the mag lips are tuned, each magazine is tested in either my 10mm RIA 52009 or 56282 pistols to ensure proper fit and feeding.  You may find some final tuning is needed on your particular pistol and it is easy to do – please click here for more information.  Buyers that are using these in both 10mm and .40 S&W pistols tell me they run without any changes needed.

3/10/22 Update:  We are now setting front feed lip gap between .370-.390 based on customer feedback.

I do have something I want every reader/buyer to remember:  PLEASE Always test the magazines before you need to rely on them - you must verify that a given combination of pistol, ammo and magazine are reliable and this is true for any firearm. My liability is limited to the purchase price of the magazine and they are warranted against manufacturing defects only (not including any required feed lip tuning) for 90 days. 

Do you have a brand new pistol?

A brand new RIA pistol will have feeding problems right out of the box because it does need to wear in and this may take 100-200 rounds.  When you get a new RIA pistol, be sure to clean and lube it.  I would then recommend cycling the slide a few hundred times (literally) to help smooth things out before you get to the range the first time.   It may still have some feeding problems after this but they will be a lot fewer.  By the way, the need to wear in or break in is very common in firearms so don't get discouraged right away.

Take Down Pin Bundle

You have an option to add one of our Full Length Guide Rod Take Down pins at a discounted price now if you are interested.


Due to irrational firearm hysteria, I will not ship magazines to locations listed in the USCCA magazine limit guide page that prohibit magazines of this size (16 rounds is my stated capacity) plus try to maintain a list of other areas. I will not ship disassembled "magazine kits" to those locations either - sorry. I can't export them either - I hate having to put all this legal stuff in but I must.  It is the buyer's responsibility to ensure compliance with all applicable laws and regulations before buying these magazines.

The following are the limits per state that we are aware of - and please email us if something has changed:

  • California: We can no longer sell magazines to California due to liability issues
  • Colorado: 15 rounds
  • Connecticut: 10 rounds
  • Delaware:  17 rounds
  • Hawaii: 10 rounds
  • Illinois: We will look up your city and county to see if you have limits.  For example, Chicago and Cook Country are limited to 10 rounds.  
  • Maryland: 10 rounds
  • Massachusetts: 10 rounds
  • New Jersey: 10 rounds
  • New York: 10 rounds
  • Oregon:  Measure 114 is temporarily restrained
  • Rhode Island:  10 rounds
  • Vermont - 15 rounds for pistols
  • Washington D.C.: 10 rounds
  • Washington State: 10 rounds

This product is export controlled by US Government Export Regulations.  We will not export to any country.

Terms and Limit of Liability

This is for one magazine - the pistol in the photos is not included.  We are not liable for any damage or injury resulting from use or misuse of this magazine.  The buyer assumes all liability.

Please do not use Paypal to purchase magazines.  We do take American Express, Master Card, and Visa so please use one of those methods.  Sorry - Paypal's policies do not allow for many firearms and parts transactions but we have quite a few pro-gun customers who do like to use them for other products we sell.


  • Item #: RIA10mmP16HCBlueV3_10rd

3rd Gen Custom RIA A2 HC 10mm / .40 S&W 10 Round Magazine

Price: $59.99
2 or more: $58.99 each
4 or more: $57.99 each
* Marked fields are required.
Availability: In-Stock
# Available: 13
Qty: *
Reviews (0) Write a Review
No Reviews. Write a Review