The product in this review: Rainier Arms MARS for Glock gen 1-3

The product in this review: Rainier Arms MARS for Glock gen 4 & 5 - Black version


I have spent the last four months training, shooting and just flat out playing and fiddling with this slick little ambidextrous Glock magazine release. I’ve put just over 4,000 rounds though my Battlefield Green Gen4 Glock19 with this little gem of a product installed. Most all of that in training courses, and on a private training range, using the product in the ways it was intended.

Before I get into the meat of the review… I can say that at the start, I generally liked the concept of this product, I generally liked how it operated, and I had a concept of how and why and when I would use it’s features… But, I had my doubts.

This little sucker grows on you. The more you shoot, train, and just plain mess around with it… this MARS mag release grows on you.

Now after 4 months of carrying this on my Gen4 Glock 19, I will say emphatically… I love this thing! And, I have found it so useful in so many other ways than I originally thought.

Now… before you chastise me and say I’m just a Rainier Arms fanboi (remember I’m a girl so I don’t know what the female equivalent is termed)… I will answer and say, “YES… I am a Rainier Arms Fanboi”.

I really do love their products and John’s company. I love their products and I love doing business with them, but more and most importantly… I absolutely respect John Hwang, the owner and founder for the type of man he is on all levels personal and professional.

That doesn’t mean I give my approval smile on everything. In fact, I am halfway through a charging handle review and during a defensive/combat style training session when I had a malfunction, due to some crummy .223 remans… I ran the charging handle up against a walls corner to clear the malfunction… and the latch broke right off. I was surprised. But, it still worked great and I continued to train with it regardless of being broken.

But… I already knew this product wasn’t really a combat style charging handle, and as much as I really like how it feels… I’m staying with my Fortis Hammer or the Radian Arms. It’s more fit for my purposes and style of training.

SO, I say all of that to say… I’m not going to give a super glowing, both thumbs up and my signature, “SMILE….” Award to everything I’m given to review.

The products still have to meet my requirements.

So… Onto the glowing review of the MARS… because this particular product really does get my “SMILE…” Award.

*** The SMILE Award: The short of it is this; I don’t ever promote any product that I absolutely do not believe in. I’ve been fortunate enough to have been trained and still train with some of the best in their respective fields, and they instilled in me a no compromise approach to my gear and kit. So for me… my signature SMILE Award is based on a product performance that makes me legitimately smile. I can’t help it actually, it happens naturally when I am able to use and run an exceptional product.

The Meat Of The Review…

Philosophy of Use: The general POU for the MARS system is to be used as an ambidextrous magazine release for either your gen3 or gen4 Glocks. In the case of this review, I installed this on my battlefield green gen4 Glock19. The gun is completely stock with the exception of a little Dremel milling under the trigger guard. The objective is to be able to use this product to release the magazine from either your trigger hand thumb like normal, or with your trigger finger on the opposite side. And of course, if you’re left handed… the same thing, but opposite side. (usually most of my lefty shooter friends just switch the mag release button to the opposite side. That’s the overall POU for the MARS.

Installation: The installation was pretty simple once we figured out a little trick with the flathead screwdriver. I’m not saying that this is the preferred method but I am saying that we have installed several of these since, and that little trick helped, and it is a snap to install.

I’ve included a video of my son (16 years of age and a shooter) who is taking gunsmithing courses through SDI, installing the MARS on my Glock19.

Ease of Use:  Once the MARS was installed, I just started fiddling with it. Official dry firing practice, and while just laying in bed watching a movie with my husband. It’s during the laying around fiddling with it that you begin to explore and figure out exactly how you personally want to use this product.

I have spent the last four months playing with this thing, by just releasing a mag and putting it back in… on and on and on and on. Literally for four months. This is where I really began to fall in love with this product. And in all honesty, I love this product not even for what it was engineered to do, which is be ambidextrous. That’s great and works perfectly, but as a straight-a-way mag release, it’s my favorite. And because we test all kinds of products, I’ve got access to the majority of all the popular brands. I prefer this MARS mag release as my standard mag release, ambi or not.

Handling Ease:  One note… I have a pretty deep undercut on the trigger hand side (right side) of my Glock 19. When I first installed the MARS and gripped my Glock, I could feel my right middle finger (the one that usually gets the infamous Glock Knuckle) pressed up against the MARS.  Not a lot but a little, to where I thought that I might accidentally drop the mag with a high strong grip.

After 4,000 rounds in the last four months, during training formats… I’ve never once dropped the magazine. The right side button on the MARS is a little stiffer than the left side and the feel and pressure applied is a little different with each side, in my opinion.

I’ll Break Down How Each Side of The MARS Feels To Operate:

Left Side:  The MARS is smooth to operate. I mean really smooth.  Understand that I do not have large hands and I’m already pushing it using a Glock 19 as my IDC (our term for EDC – see my article on The New EDC Terminology). My G19 has a flat trigger installed so I can shorten the trigger reach a bit.  This helps. So with smaller hands and a Glock, hitting the mag release button during reloads whether in a competition or defensive training (hard for me to use the word “tactical” since I am not an Operator)… has always been a little tough for me, especially at speed.  Meaning… I would rather not really adjust my grip on the weapon while trying to hit the mag release. I’ve tried extended buttons, competition buttons, etc… Didn’t really like any of them.

Not to mention, that they all have the same feel in the action. Get your thumb on the button and press down.

The MARS has a very different feel to me. There’s no direct downward push on the left hand side. It’s easy to reach with my thumb without over exaggerating my hold and flipping the gun.  You can just run your thumb across or up the ramped button and that sliding pressure drops the mag. Doesn’t mean that you can’t apply direct downward pressure, it just means that this is the easiest and fastest mag release, my husband and I have ever used.

Right Side: For a right-handed shooter, I thought this would be a great product. Giving a shooter both sides as options to drop the magazine. Similar to my HK VP9 with the paddle mag release, Which I initially liked.

When first using the MARS on the right side my initial attempts were to manipulate the button with my trigger finger.  Which was fine and it worked, but for me… I felt like I still had to flip the gun just as much as I did when dropping a mag on the left hand side with my thumb.  This was because the pressure applied on the right side is different than the more sliding pressure motion on the left side.  And even without my trigger guard undercut on the right side… using the trigger finger to manipulate the MARS button, finds my middle finger in the way.

The reason is that the right hand side has a little lip towards the trigger guard and you press the tip, which is slightly angled.  Let me say, that it works perfectly. But I found after playing with the MARS for a while that I actually preferred (Found it easier, faster and less adjusting of my master grip) manipulating the right side button with the middle finger at the first knuckle.  Right on the crease of the knuckle, where you would typically get Glock Knuckle. I really like this method of manipulating and using the MARS.  The more I worked it that way, the more I liked it and now after doing it that way for the last four months… It’s ingrained.

Running Support Hand – Support Off Hand:  All I can say is ARGH!!!!  I am not remotely ambidextrous.  My husband who is a former professional athlete in a few sports, seems to be able to do the same things the same way with both hands.  In fact he’s usually better with his non-dominant hand, than most people are with their dominant hand.  But not me…Which of course then frustrates me when we are at the training range and he’s takes the MARS and says… “See… do it like this.”

The MARS is perfect for left shooters, if they choose to use it in this manner. I had a few lefties run it for a day at training and they loved it.

Me personally… It worked, and I worked to get better at my technique, but it wasn’t pretty.  I’m sure you can see that in the video mash-up.  I will say, that IF I ever end up in the situation where support hand-off hand becomes my only way to fight my way out… I’m glad I have the MARS installed on my Glock.

Fit and Feel:  To me… perfect. Nothing get’s in the way. No accidentally mag drops (Yes, I’ve had issues with this, just ask my buddies). Looks fantastic on my Battlefield Gen4 Glock 19. Plus it comes in a few other colors.

Warranty: It’s Rainier Arms. No need to say anything else.

Quality Construction-Components:  High quality product. Manufactured extremely well, as is every Rainier Arms product I’ve ever used. And I like that it’s a solid bomb-proof product, and that there is no button tab to screw on the actual mechanism.

This thing is dead on for competition, combat, or duty use. Having had a lot of my SF Combat Vets and SWAT buddies run it during some trainings. Wish it was legal for USPSA Production. Since it operates with the speed and effectiveness of a competition mag release, but it’s not a competition mag release.

Looks & Esthetics: Good looking product. Fit and finish is perfect. No over aggressive textures, everything is flush with the firearms frame, etc…  I did slightly sand the bottom edge on the right hand side to smooth it out. This is because when I use my middle finger to manipulate the button, I drag it across the button. So I added a little light sanding to make a smooth bevel, and it added a great little touch.

Reliability: Just over 4,000 rounds so far… haven’t had a single problem yet. It did take me a few days to really get the feel down, for the right hand side, based on how I wanted to actuate the MARS button.

Company Reputation: It’s Rainier Arms… what else is there to say. This is they’re product and they stand behind everything they sell.

Suggestions: Everyone has their own preferences and loyalties to different brands and products for a variety of reasons. I like and use this product because it has proven to me to work, and work better than any mag release I’ve used, regardless of being ambidextrous or not.

Things To Watch Out For:  Nothing. Little adjustments, maybe, for your preference, and the set up of your particular Glock.

Overall Performance: Once again, just over 4,000 rounds and four months of solid weekly use and daily fiddling. Works better than I thought it would. It personally took me a few days and a few training sessions to figure out how I wanted to work it.

Whether for CCW, Competition, Duty, Home Defense, etc… this product worked for me and those on my team, and agree that this product works, and can be used for anything you do with your Glock.

I’ve carried my Glock19 appendix, and it doesn’t snag, doesn’t accidentally drop the mag by pressing or rubbing up against my RDR Kydex Holster. And overall, makes it faster and more effective and efficient to drop mags.  No matter your usage… to me, that is what counts the most.

Things That Should Be Changed: Nothing. You may not like it, but that would be because of a personal preference towards another product someone is currently using.

Things You Would Personally Change: Nothing that I couldn’t adjust, with a little light sanding.

Will Women Like It?: Absolutely YES! I will strongly suggest that if you run Glocks, that you install this MARS product. Believe me when I say, that it will make reloads way, way easier and faster.

In Closing

Remember, that this is all coming from my perspective and my experience with the MARS Ambi Mag Release.  I am not the fastest at mag changes and emergency and speed reloads. I still get a little loose and end up with the gun further out from my body when stress is added during training. I’m working on that constantly. It’s just counter-intuitive for me.

In fact, I am really working on that general concept, even in my combat jiu-jitsu training. Working from that center core space where there’s control and power.

This product gets my SMILES Award. But… it did take me a while to get more proficient with it. That was a function of having to work on my own technique.

Otherwise… this thing works. And it works better than I thought it would, and it got better the better I got.

Check it out in action:

In case you missed it: Rainier Arms M.A.R.S. Review and How to by JS

The product from this review: Rainier Arms M.A.R.S. for Glock gen 1-3
The product from this review: Rainier Arms MARS for Glock gen 4 & 5 - Black version