First Gear | Breakout Versatility: Glock 34/35 MOS

posted on January 17, 2016

Glock G34 MOS 

There are not many pistols out there that we like better than the long-slide Glocks, and especially the G34 (9 mm) and G35 (.40 S&W). To fabled reliability and accuracy, they add longer sight radii and barrel lengths, as well as a “match” parts tune to controls and the trigger. These have been supplemented over the years by the “Gen4” upgrades to the grip/beavertail, an ambi-mag release, and a dual-coil spring system. It’s one of the very few pistols you can take right out of the box and use to qualify for a nationals-level competition: Been there, done that, have the t-shirt.

You might (reasonably) think there isn’t much left to do, but we’d politely suggest you’re mistaken, as the G34/35 MOS pistols demonstrate. While not exactly new (the MOS versions were announced at SHOT in 2015), the difference may be a little subtle even for fairly sophisticated pistoleros/as. The big deal here is that with MOS—Modular Optic System—Glock has brought “in-house” one of the best possible options on a thoroughly modern pistol: a straightforward way to add reflex sight technology.

We’ve talked about this sight tech before, and here’s the short version: Using a small, efficient light source and a curved lens, these sights overlay a bright, precise aiming point on the target, even in bright daylight. Not only are they astonishingly tough and really speedy in the target acquisition department—once you get used to them—they also solve a huge, annoying problem for many with eye issues: The dot is on the same visual plane as the target, so your distance prescription or correction renders the aiming point and target in welcome, uniform clarity.It’s one of the very few pistols you can take right out of the box and use to qualify for a nationals-level competition.

What the G34/35 MOS brings to the party is adding this technology to your pistol for essentially nothing, other than the cost of the sight. Long the province of extensive/expensive milling of your existing slide and careful selection (or outright fabrication) of a mounting system, Glock simply includes a set of four baseplates with each MOS pistol, and you select the one that matches the base of your reflex sight. Two screws pop off a filler plate and secure the baseplate, and two more screws—those provided with your sight—attach the sight itself (a list of optics here). Ten minutes, tops.

Our pictured combo is a G34 with a Burris Fastfire III, and we can only rave. We haven’t shot the reflex/red-dot technology enough, but our last excuse is now out the window.

At present, MOS Gen4s are limited to the “small frame” G34/35, and “large frame” G40 (10 mm) and G41 (.45 ACP) models. With yet another SHOT Show looming, we’ll hope we can expand this list of MOS Glocks for you. The technology isn’t superb only for competition and hunting as implied by the original, longer-barreled pistols, but also to many defensive, law enforcement and military roles as well.  

And just plain fun? Oh yeah! 

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Mag-na-port + Lone Wolf

If you’re already fired up about a MOS Glock, we issue a warning: We’re going to make it worse. Guaranteed.

We’ve had good luck over the years with Lone Wolf Distributors’ products, and particularly their conventionally rifled barrels (and caliber-conversions) as well as their superb G9 Carbines. But when the G34/35 MOS pistols appeared, our enthusiasm was really sparked, and the reason will soon be clear. 

In order to keep slide dynamics similar to the standard/duty-sized Glocks (G17 and G22), the longer pistols have what’s commonly called the “balancing cut” in the forward, upper surface of the slide. This elongated oval reduces slide mass, and does its job very well: Most folks find very little difference in the “feel” of the standard guns vs. their long-slided cousins, yet the latter accrue the velocity and sight radius benefits typical of the added barrel length. Well done, Glock.

… that opening is just about perfect for another really nifty reason: It makes the long-slide pistols easy to “port,” in the original fashion, a la Mag-na-port …But as it happens, that opening is just about perfect for another really nifty reason: It makes the long-slide pistols easy to “port,” in the original fashion, a la Mag-na-port International of Harrison Township, Mich. Pioneered by Larry Kelly in the 1960s and kept going today by son Ken, Mag-na-port (like other compensating technologies) vents combustion gases upward as the bullet passes ports cut in the barrel. What’s particularly useful, however, about this form of recoil reduction is that it has essentially unmeasurable impact on velocity, adds no weight or length to the firearm, and doesn’t require any refinishing: The spectacularly precise Electrical Discharge cutting method blends the existing finish into the metal.

Mag-na-port and Lone Wolf fixed us up with barrels for our MOS Glocks, and the results were well nigh fabulous. We’d say the recoil reduction hovered between 20 and 25 percent, and there’s no easy way to describe what that means when combined with a reflex sight. Particularly in the G34 (9 mm), lighter bullet loads seemed to leave the sight picture all but undisturbed, though even the thumpier .40 S&W muzzle settled back where it belonged with fairly spooky haste, too.

Acquiring and porting a barrel to work with your MOS long-slide Glock starts at $99 times two (barrel + porting). And we think it’s worth every penny

Visit Mag-na-port International at Visit Lone Wolf Distributors at

Robar/GlockKraft Trigger

We expect a few readers have gotten to this question before us and, if so, congrats: “If I’ve got a red-dot/reflex sight, and a ported barrel, aren’t I perilously close to an ‘Open’ or ‘Unlimited’ style gun?!” 

To which we reply, “Yes, you are.”

For those unfamiliar with what this means, we’ll get you up to speed: “Open” or “Unlimited” divisions are found in several classes of competition, and they’re generally the absolute, no-holds-barred versions of modern handguns. Another way to think of them is as the “test beds” of handgun technology. What appears here often becomes law enforcement, military and defensive kit down the road.Another way to think of them is as the “test beds” of handgun technology. What appears here often becomes law enforcement, military and defensive kit down the road.

It seems to us that this trigger upgrade could hardly be more complete: A Glock™ OEM mainspring/ejector housing anchors a Wolff X-Power 6-pound trigger spring, OEM trigger bar and “minus” connector (all properly deburred, polished and NP3ed), and fronted outside the gun with the GlockKraft Aluminum flat-faced trigger (in either NPS or black hard anodized). Not only is this a jewel of a trigger (as we said in more detail here), it’s just about the perfect “icing” to a Glock/Mag-na-port/Lone Wolf Open gun “cake.” Just add some magazine baseplates, and you’re racing, as our creative director likes to say.

Best of all, our G34/35, ported aftermarket barrel and trigger upgrade is like having about four pistols instead of one: none of our suggestions consume original parts. In USPSA parlance, and in a maximum of about 15 minutes, you could reconfigure your gun and shoot it in a Production, Limited, Limited 10, Carry Optics or Open division. About $1,200, all told.

If that isn’t value and versatility, what is?

Visit them at



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