by Tom Gaylord
Writing as B.B. Pelletier

Crosman MAR
The MAR177 from Crosman.

History of airguns

This report covers:

Tested before
From 2012
The AR system
The lower
National Match lower
Stopping here
Buying the MAR
The purpose of the MAR
What is the MAR177?
Where did it come from?
What about THIS one?|

Today is the big day and now you know. This report will be about the Crosman MAR177. As I told reader Brent on Wednesday, this gun is no longer being made, yet I believe the one I am testing is brand new. By sheer luck as I was researching another article I stumbled across this New in the Box MAR177. Apparently it has never been out of the box, because the accessories are still factory wrapped.

Tested before

I tested the MAR177 extensively in 2012, right as it hit the market. I was asked to write a feature about it for Shotgun News. To test it I had to build an AR-15 lower, because the MAR177 isn’t a complete airgun. It’s just the upper to an AR-15 or M16 lower. Let’s look at that history first.

From 2012

The MAR177 is a target precharged pneumatic upper that fits on any standard National Match AR lower (I’ll cover that in a moment) and turns the U.S. M16 service rifle or its civilian-legal semiautomatic counterpart AR-15 into a target air rifle. Those airgunners who own AR rifles can buy the MAR177 right now and have a target PCP that’s ready to go. This report will be a thorough test of that rifle. One caveat — some AR-15s made by Colt have larger pins for the upper/lower connection and special steps must be taken for them.

I didn’t own an AR-type rifle at the time. From my time in the Army I had grown to distrust the reliability and accuracy of the platform. That had changed by 2012, but being a hater I wasn’t aware of it. None of my shooting friends owned one, either. So, I was at a disadvantage when I was asked to report on this unique new air gun.

There have been other air rifles before now that have resembled the AR-15/M16. Crosman just introduced their M4-177 multi-pump rifle that I tested for you in 2011, and back in the 1990s they made the much simpler A.I.R. 17 — another multi-pump that was crude but did follow the AR styling. So, the story is not that an AR airgun has been made. The story is that this one is a precision target rifle and could rival some 10-meter rifles.

The AR system

Before I continue, everybody needs to be on the same page. The AR system that the Crosman MAR (modular adaptive rifle) belongs to is comprised of two principal subassemblies — the upper receiver and the lower receiver. The upper receiver contains the barrel, gas system, bolt, sights and operational hardware for the rifle. The Crosman MAR177 is an upper. I will talk a lot about the upper throughout the rest of this report, but let’s look at the lower receiver for a moment.

The lower

The lower, as it’s called, is a frame that contains the operational parts, pins and springs for the trigger, selector and safety, magazine catch, as well as the buttstock and buffer assembly. It’s considered by the Bureau of Alcohol, Tobacco, Firearms and Explosives (BATF&E) to be a firearm. It’s the part that has the serial number. You can buy and sell uppers almost anywhere in the U.S. without paperwork, but each lower is classified as a firearm. The fact that this is a modular system with many different uppers — all on one lower — allows you to own many different rifles of different calibers, all under one registration.

But I didn’t own an AR — so I didn’t have a lower receiver. And the MAR177 was never sold as a complete rifle. Crosman had plans to build it that way at some time in the future, but those plans never materialized. I needed to get a lower.

At first, I looked around for just a complete lower receiver to buy used, and they do exist, but as I searched I found that the people who have them don’t always know exactly what they have. For example, the upper and lower attach via two cross pins, and there have been different sizes of pins over the years. Colt made pins that were larger than those made by other manufacturers, so you might get a Colt lower that doesn’t fit the MAR upper. There are bushings to reduce the sizes of the holes in the lower; but since I was doing this from scratch, I didn’t want to begin with a workaround.

I located a brand new Rock River Arms lower receiver that was stripped of all parts. It was just the receiver shell by itself. But there are parts kits to build up such receivers, so I went online and ordered a National Match lower parts kit and an A2 buttstock assembly from Rock River. I would build the receiver myself, and when finished, I would have a complete Rock River lower — not a bad thing to have. Rock River is a good name — one of many you will find if you look. And there are also a few names to avoid — just as there are with airguns.

Rock River lower receiver
A bare Rock River National Match AR-15 lower receiver.

When I placed the order, though, I failed to notice the fine print at the bottom of the Rock River webpage that said some of the parts were on indefinite backorder. They didn’t specify which parts those were from the hundreds of choices on the page, but sure enough it turned out to be the entire parts kit I needed for this report. That’s because Rock River is currently experiencing a 60 to 90-day backorder status on their whole rifles, and they certainly aren’t going to sell their parts faster than they can build entire rifles to sell. It makes perfect sense, but only when you know it. And I only found out when I didn’t get the parts I ordered. So, I had a stripped receiver without the parts to complete it.

[Editor’s note: This was the height of Barrack Obama’s first term, and firearms were flying off the shelves — particularly the AR-15 platform!]

Once I realized my backorder status, I placed a call to Rock River to see what the expected delivery date would be, and that’s when I learned everything I have just shared with you. I then explained my short publishing deadline to them (a special feature article in the July color issue of Shotgun News) and they bent over backwards to fix the problem — but don’t expect them to do the same for everyone. If you want to build a lower receiver, you had best first pin down a source for parts before doing anything else. So, this test is made possible through the good graces of Rock River Arms, who, before last Wednesday, had never heard of Tom Gaylord.

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National Match lower

Now that you know what a lower receiver is, what’s so special about a National Match lower? Simply put, it’s a lower that meets the specifications for the U.S. Service Rifle National Matches held at Camp Perry, Ohio, every year. One of the most important aspects of this specification is the trigger. Standard AR rifles come with single-stage triggers that are barely adequate at their best. But the National Match specification allows for a two-stage trigger that breaks cleanly with no less than 4.5 lbs. of force. There’s a host of additional information available for National Match triggers; but for our discussion, this is sufficient.

I was hardly going to test the MAR177 — a target rifle — with anything less than a good trigger. I say “good” advisedly; because to someone used to a nice match airgun trigger or even a Rekord sporting trigger, these AR triggers are fairly crude — even those that are National Match. But in the sport they’ll be used, the National Match triggers are as good as you’re allowed to have. Testing the new air rifle upper with a stock single-stage trigger would be a crime.

Stopping here

The old blog goes on and on about me building the lower I needed to test the MAR177. It is very interesting stuff, but I have given you a link to Part 6 of that report and there you will find links to the five earlier parts. I am going to now skip ahead so I can talk about the subject airgun.

Buying the MAR

I found this airgun on Ebay, and from the photos it looked like it had never been used. As I unpack it and examine it, I will comment on that if necessary, but at this point I believe this is a new-old-stock MAR. I opened the box one time upon delivery a few weeks ago and haven’t touched it since. Today I photographed it as I opened the box for only the second time. I want all of you to see this as I am seeing it.

Crosman MAR box
The MAR box as I received it. It looks identical to the box I received in 2012 — and yes, I can still remember it.

Crosman MAR box open
The box opened. I am seeing this for the first time with you, because the packing bubbles that were inside have now been removed.

Crosman MAR accessories
The accessory package contains the manual, the false magazine insert for the MAR (for proper balance and hand placement when firing) — still in its sealed factory foam wrap — the 10-shot circular magazine (a Marauder mag) that fits into the receiver, an Allen wrench to depressurize the reservoir, a tube of Crosman Silicone Chamber Oil that has been opened and various pieces of Crosman literature, including instructions for loading the Benjamin Marauder rotary magazine.

Crosman MAR accessories out
All the accessories.

The purpose of the MAR

The MAR was developed to allow AR-15 and M16 shooters to train with pellets that are both cheaper and safer than .223 Remington/5.56mm ammunition. We have seen military trainers like this before — most notably the Hammerli Trainer insert for the Swiss K31 military rifle. Like the MAR that was also not a complete airgun, but required the service rifle to operate. The theory was a soldier would be able to train with his own service rifle shooting inexpensive BBs and close range. That training was safer, quieter and much less expensive, plus it did not require a formal rifle range.

K31 rifle
Swiss K31 military rifle.

Hammerli trainer
Hammerli trainer insert for the Swiss K31 rifle.

Crosman MAR 177 complete
This is my actual AR-15 with the MAR177 I tested in 2012.

There is or was a set of rules in the CMP rulebook for an AR-15 clone airgun. As far as I can tell, no specific match was ever run for the MAR177.

What is the MAR177?

You already know that it’s a trainer for the AR-15/M16 platform, but what is it? It is a 10-shot repeating .177-caliber precharged pneumatic target rifle. The box says “High-Powered Simulation AR Competition PCP Rifle.” It certainly is not high-powered, as the box also says the expected velocity is 600 f.p.s. That is a target rifle velocity. Perhaps someone meant the MAR is a simulation FOR a high-powered rifle, but the wording seems vague.

Crosman MAR 177 box detail
Regardless of what the box says, the MAR177 is not high-powered.

Though it is mounted on an AR lower and is a repeater, it is not semiautomatic. It must be cocked for each shot by pulling back what would be the charging handle on an AR, but on the MAR is the bolt handle. The rotary mag is spring-loaded, so when the bolt is retracted, the mag advances to the next pellet. Pushing the bolt home pushes a pellet out of the mag and into the breech of the barrel.

This is no lightweight flimsy add-on. The MAR177 I’m testing weighs bang-on 7 lbs. and will gain several more pounds when the lower is attached. This isn’t some kid’s plastic AR truck gun. It’s a National Match stand-in that does the job.

Where did it come from?

The rifle that served as the basis for the MAR177 was developed by Scott Pilkington, the man who used to support the American Olympic airgun shooting team. He put his rifles together with real AR components, and added his own custom parts to interface to them. He took that idea and gun to the Crosman Corporation and sold them the idea and plans, and they developed it into the MAR177.

The MAR was a top-end air rifle, or the greater part of one. The barrel was from Lothar Walther and all the components were solid and well-made. That quality drove the retail price to $600 in 2012. As I said it was a time when ARs were in great demand, but apparently a top-flight air rifle upper that cost twice what a lower-end firearm upper cost in the day was too much for the market to bear.

The rifle is not regulated, but my tests that were conducted in 2012 revealed a very consistent valve. Naturally I will test this one for you as well.

Ed Schultz who worked on the MAR told me it was always his hope to make it a semiautomatic rifle, but the gun didn’t remain in production long enough for that. From the research I have conducted it seems likely that between 500 and 1,000 MARs were produced between 2012 and 2015/16 when production apparently ended.

What about THIS one?

I took the MAR out of the box for the first time today, while writing this report. I think that is the first time it’s been out of the box since it was built. The clear plastic sheet was still on the face of the pressure gauge on the bottom of the rifle — more evidence of a NIB gun.

Crosman MAR 177 gauge
The clear plastic film was still on the face of the gauge from the factory.

I filled the gun to 3,000 psi four hours ago and the onboard gauge says it is holding. I filled the male fill nipple with Crosman Silicone Chamber oil prior to filling with air, so the oil would be blown in and get on all internal seals. I will keep an eye on the gauge as time passes.


There is so much more to report that there will be more description stuff in Part 2 and perhaps in the other parts as we go. Now that I have an AR-15 of my own, I think this guy is home to stay. But there is more.

This is a great idea that died for many reasons, but the entire idea doesn’t have to go away. What if an AR-15 upper could be made that would be more like the Hammerli trainer insert for the K31? It would be a BB gun — not an pellet rifle. No expensive Lothar Walther barrel, but an accurate BB barrel like the one on the Daisy 499. The steel BB has been refined to the point that it is highly accurate over short distances. And there are tens of millions of AR-15s, M16 and clones in the world that could use such an airgun.

I would have bought that MAR I tested in 2012 if I could have afforded it, but my lengthy stay in 2010 in 4 hospitals left Edith and me burdened with a huge debt. So, when this one recently became available I did what I had to do, to acquire it. 


This may be one of the most important blogs I have ever written. Not only is the MAR177 one of the most important airguns Crosman ever made, the concept is many orders of magnitude greater. Only time will tell how far this may go!