Glock first announced the G21 back in 1990, in a host of caliber changes that offered more than the company's 9mm initial offerings-- the G17 and G19. Announced that year were the aforementioned G20 and G21 along with the .40 S&W caliber G22. At introduction, these were 2nd Generation guns, a series only gently updated from the company's original debut in the mid-1980s.
I've been fooling with the G21 off and on for almost 30 years. My first was a Gen 2 AAZ-serialized G21 that I picked up in 1994, just as the federal AWB and magazine cap kicked in that chopped the standard mag capacity from 13 rounds to just 10. I kept that tough-as-nails .45 through Hurricane Katrina, during which and immediately after it was never far away, and only passed it on to its current owner in 2006, downgrading to a 9mm as my everyday carry.
Then came the Gen 3 Sport/Service models in 1997, which brought with them recessed thumb rests, finger grooves molded into the frame, and, eventually, an accessory rail.
The Gen 4 G21 arrived in 2011 with the company's improved RTF-4 texture, interchangeable frame back straps, a reversible enlarged magazine catch, a dual recoil spring assembly, and a new – some would say improved – trigger.
And since then, the G21 has been frozen in time, locked in 2011, although Glock threw fans a bone with limited-run batches of FDE, OD green, and gray framed subvariants. In the meantime, the company introduced their 5th Generation guns – but only in 9mm (G17, G19, G19X, G26, G34 and G45), .40 S&W (G22, G23 and G27) and .22 LR (G44).
Now, Glock finally reached back and brought the old "large frame" 10mm and .45 full-sized pistols into the present.
What the 5th Gen brings to the G21
While keeping the same 13+1 round magazine capacity (although not with backward compatible magazines), and overall rough size and shape as previous generations of G21s, the new model drops the finger grooves on the grip, adds a gently flared magwell for faster reloads, and comes standard with ambidextrous slide stop levers.
Glock has tweaked the 5th Gen triggers for a smoother pull and improved reset over past generations. Sadly, while the company announced its new flat-faced Glock Performance Trigger at the same time as the trio of new 5th Gen guns, the enhanced trigger isn't included on these guns yet – and won't be an option for the G21 as the new pack is for 9mm pistols only.
Optics ready
A big bonus on the Gen 5 G21 is that it comes Modular Optics System, or MOS, standard. That is a first for the pistol, as users had to get their slides milled in years past. The only .45 ACP in Glock's catalog that came with the MOS package until this year was the practical/tactical Gen 4 G41 longslide.
Whereas Glock pistol models in standard MOS configuration previously came with four numbered DLC-coated steel adapter plates and hardware in a blister pack, newly announced MOS series guns – the G20 Gen5 MOS, G21 Gen5 MOS, and G47 MOS – will only come with the No.02 plate that will fit Trijicon, Ameriglo, and Holosun (except 509) pattern red dots. The others will be available from Glock for about $10 each.
We've got an initial 100 rounds through the new Glock .45 on the block with zero issues to report and will be back with a full review as soon as we up that round count significantly.