In recent years, we've seen more outdoor adventurers choosing to use polymer-frame, semi-automatic pistols chambered in 10 mm Auto as trail guns in place of big-bore revolvers. As this transition has been taking place, we've also seen a few long gun manufacturers choose to offer folding and takedown carbines chambered in 10 mm that feed from pistol magazines. These include models like the Smith & Wesson M&P FPC and TNW Firearms' Aero Survival Rifle (ASR).
For 2025, KelTec has gotten on board the 10 mm carbine train with the release of a SUB2000 GEN3 in this caliber. In production since 2001, these top-folding carbines have been available in various pistol calibers over the years, including 9 mm, .40 S&W and more recently, FN 5.7. But this is the first time this platform has been available in this potent caliber.
Previous GEN3 models have all been built around the same lightweight receiver assembly. However, some changes were required to beef it up a bit for the more potent 10 mm cartridge. The SUB2000 is a straight blowback-operated carbine in which the bolt and the pressure of the recoil spring are the only mechanisms to hold the cartridge in place until the gun is fired. When a round is ignited, there are no locking mechanisms or delays to manage the rearward movement of the bolt assembly beyond the bolt's mass and the resistance of the spring. This makes for a simple, rugged and reliable action design. But it also means that the only practical way to compensate for greater levels of pistol cartridge pressure is to increase the mass of the bolt assembly and use a heavier spring.
To do this, the most notable outward change to the carbine is the steel buffer tube which also supports the shoulder stock. It has been enlarged from an exterior diameter of 1 inch to 1.25 inches. This, in turn, makes room for a larger, heavier bolt assembly. The added weight of the bolt, along with some other modifications to the carbine, becomes noticeable when picking it up. Although the 9 mm version of the SUB2000 GEN3 I worked with previously tipped the scales at 4 pounds, 6 ounces, the 10 mm model sent for this evaluation weighs 1 pound, 6.7 ounces more. The grip frame has been modified to accommodate the longer, full-size Glock G20 magazine. But otherwise, the profile, features and external dimensions of this SUB2000 remain the same as other members of the GEN3 series. You can delve into the details of this latest generation here.
In preparation for the range evaluation, this carbine was fitted with a Riton Optics' X1 TACTIX ARD red dot ($99) mounted to the carbine using the quick-release, AR-height riser that ships with the optic along with a second low profile mount. This is a simple, affordable optic that I've worked with before. In fact, it’s the same optic I've used with the GEN3 carbines chambered in 9 mm and FN 5.7. I’m hoping to pull together a comparative set of data across all three calibers and using the same optic for all of them eliminates a variable in the testing process.
No one is going to accuse the carbines in the SUB2000 series of being too pretty for hard use in the field. But what this gun may lack in terms of eye candy is compensated for by its compact size and useful feature set. The two-stage trigger pull was 4 pounds, 5 ounces, according to a Lyman Products digital trigger gauge, with a clean feel and a distinctive break. All of the controls worked properly with the fore-end twisting to the right or to the left when folded so as to accommodate the optic.
This gun was tested with two Glock factory G20 15-round magazines, one of which shipped with the gun and the other borrowed from a custom Glockmeister G40. The gun fed, fired and ejected all of the ammunition tested reliably using both magazines. There were no malfunctions of any kind throughout the course of testing.
The 10 mm Auto was initially developed with the goal of improving the performance potential of the 1911 pistol. But it has proven to be one of the handgun rounds that really shines when fired through carbine-length barrels. With the slower loads, it shows modest performance gains comparable to those seen with 9 mm and .45 ACP carbines. But with hotter, light-bulleted loads, it's possible to see bullet velocities move up to over 2000 fps. This shift in performance potential played out clearly with the loads used for the formal, bench-rested portion of the evaluation. Five, five-shot groups were fired into paper targets posted at a distance of 50 yards. A Garmin Xero C1 Pro chronograph was used to measure bullet velocities for 10-shot strings.
The heavy-weight bullet and practice-grade load categories were covered by Federal's 205-grain Syntech Range load. It gained 86 fps when compared to the manufacturer's listed velocity. More is definitely more, but it’s still a fairly modest increase. Unfortunately, the accuracy was not where I hoped it would be with this carbine, even though this round has performed well for me when fired from a handgun.
The middle-weight load was represented by Federal's Train & Defend series round topped with a 180-grain jacketed hollow point which gained an average of 180 fps when fired from the carbine. That's a notable increase. The jacketed bullet accuracy was also measurably better than that of the polymer-coated, soft-lead bullets of the Syntech load.
But the load that gained the most from the longer barrel was the G9 Defense 95-grain fluted-copper solid, which the company calls an "external hollow point." The average velocity was 2,140 fps. That’s 420 fps faster than the company's listed pistol velocity of 1,720 fps. Sometimes, pushing a lighter pistol bullet faster through a longer barrel can result in larger groups down range. But in this case, the G9 load also punched out a 1.05-inch group, which was the best individual group of the test. Here is a complete set of range results:
The latest version of the KelTec SUB2000 GEN3 carbine is a welcome addition to the growing selection of folding and takedown PCCs chambered in 10 mm Auto. It's a compact and handy option that can be put to work as a camp gun, trunk gun or for hunting medium game at close range. And when loaded with the right kind of deep-penetration ammunition, it has enough punch for defense against dangerous game. The gun I worked with proved to be utterly reliable with effective levels of accuracy.
I know of some industry members who take pleasure in bashing KelTec products because they find them to be less cosmetically pleasing than some other options. But George Kellgren has been clear in the past in stating that he wants to offer his customers firearms that are both innovative and more affordably priced. As of this writing, this version of the top-folding SUB2000 is listed for a suggested retail price of $599. This makes it between $100 to $150 less than competing models. For more information, visit keltecweapons.com.
KelTec SUB2000 GEN3 Specifications:
Manufacturer: KelTec
Action Type: blowback-operated, hinged-barrel, centerfire carbine
Chambering: 10 mm Auto
Barrel: 16.15-inch black oxide finished alloy steel, round profile, 5/8x24 TPI threaded muzzle
Receiver: black polymer clamshell
Magazine: 15-round Glock G20
Sights: none
Trigger: two-stage; 4 pounds, 5 ounces pull (as tested)
Overall Length: 29.25 inches (stock collapsed)
Overall Length Folded: 16.15 inches
Drop at Comb: none
Drop at Heel: none
Length of Pull: 13.25 inches, 13.75 inches or 14.5 inches
Weight: 5 pounds, 12.7 ounces with empty Glock magazine
Accessories: one magazine, knurled thread protector, lock, owner's manual
MSRP: $599 (black finish)
