Double Diamond .40cal to 9mm Conversion Barrels for Glock
$99.99
SAVE MONEY ON AMMO! Reduce Recoil!
Easily convert your .40 Caliber Glock to shoot 9mm in seconds!
Designed to allow shooters to change calibers by simply dropping in the Double Diamond conversion barrels in conjunction with the appropriate caliber magazine. The barrel is cut to fit in the ejection port of the intended slide. Basically, it’s a .40 caliber barrel on the outside chambered in 9mm … brilliant!
Swapping out recoil guide rods, ejectors, extractors, or strikers is not necessary.
Please note: Will work in Gen 1, 2, 3 and 4 Glock handguns. Threaded Conversion Barrels will NOT work with most compensators.
Looking to convert your .45ACP to 10mm?
Click here!
Got a 10mm and want to shoot .40 S&W?
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9 reviews for Double Diamond .40cal to 9mm Conversion Barrels for Glock
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Big Jer –
Received one of the last generation barrels recently for my Glock 23. What a difference. The .40 barrel would throw rounds in a varied grouping but once I got this sighted in, shoots a very nice group at 25 feet. Would recommend highly. Sidenote, threaded DOES come with a thread protector already. Add a little blue loctite to keep it in place.
Scott –
600 rounds through it so far and zero problems. I did replace the extractor and ejector with Glock 19 oem parts. No FTF or FTE problems at all. Also no problem with brass hitting me in the face. Beautiful fit and finish. Thank you Glockstore!
Mike –
Got to take this for a walk at charity event shoot for 4 days.
Threw this in my G22 Gen3 and fed it S&B 115gn fmj. The barrel was machined true, could ragged hole at 7yds. Good enough for my eyes.
Downside: In 800 rounds I had 14 Type 3s. Could be a lot of things including the ammo, however, my G19 Gen2 ate the same amount of the same ammo and got 1 Type 3. In this case, maybe not the ammo. Could have been tired hands.
Take Away: I wouldn’t use it for carry, but for range work I think it’s awesome. Besides, Type 3s are my favorite. Finger magic.
Kane –
I’m completely satisfied with this conversion barrel and with the CustomerService I received from the glock store. I waited for a sale and got the barrel for 116 bucks with free shipping and after ordering I live chatted with Conor An he told me it ship towards the end of the week I ordered it on a Tuesday it shipped on Thursday and got it Friday… since installing (in my glock 35 G4) i have put about 100 rounds through it no problems great fit and finish and very accurate… I have nothing negative to say if you are thinking about buying this barrel you wont regret it
Gary –
Since I converted my Glock – 23 from a 40 cal to a 9 mm it works like a charm. At first I had a feed problem because of the new Gen 3 lower but it went away after a few rounds
D –
Great quality, perfect workmanship. Accuracy on par with Glock factory barrels. As good ( maybe better?) than my Glock 26.
James Kirkland –
Very nice barrel but needed a little fitting around the top lip over the chamber to fit into my slides. Otherwise happy with the purchase
Eric –
I purchased this conversion barrel for my G23 and I can confirm that the pistol functioned FLAWLESSLY!!! The only other amendment was the addition of G19 magazines. I experienced no FTF, FTE, no malfunctions whatsoever!!…I was originally going to purchase the 9mm specific extractor just to be safe, but never got around to it. Went to the range this morning for yearly quals, and brought my MCK with the G23 (9mm convert) and it shot beautifully!!
zippy355 –
I carry a Glock 27 and I also have the 40 to 357 sig conversion barrel. both perform flawless with standard 40 cal mags!