Which factory extended mags do you trust?

[mmc45414]

I bought one of these, and it works well in a little shooting, so I ordered two more today.

One distinction is that it is not an extension, the magazine body is full length, and the plastic that looks like an extension is actually a floorplate that shrouds the bottom of the magazine on the front and sides. So even though I have not done a ton with one, the concept seems trustworthy to me, more so than something that is tacked on.

My plan for the three of them is set one up in my JMCK AIWB mag pouch, set so the mag will go low and leave the "extension" poking out to grab.
Another one will get loaded for my nightstand gun, and the remaining one will ride in the range bag and will get used if a 3gun stage looks like it could be a high round count, like an MGM Spinner or something.

[WobblyPossum]

I haven’t personally seen or experienced any issues with OEM 9mm Glock mags using their +2 extensions (33rd, 19rd, and 12rd) or with the 21rd OEM Sig P320 mags. As posted upthread, there exists a possibility for over insertion with the P320 mags if you really gorilla the reload and shove the magazine past the mag catch. You can bend the ejector upwards and deadline the gun. I don’t have experience with any other mags using extensions for increased capacity.

[Clusterfrack]

I haven’t personally seen or experienced any issues with OEM 9mm Glock mags using their +2 extensions (33rd, 19rd, and 12rd) or with the 21rd OEM Sig P320 mags. As posted upthread, there exists a possibility for over insertion with the P320 mags if you really gorilla the reload and shove the magazine past the mag catch. You can bend the ejector upwards and deadline the gun. I don’t have experience with any other mags using extensions for increased capacity.

This is crucial info for P320 users. I’ve personally seen two guns ruined this way.

[WobblyPossum]

This is crucial info for P320 users. I’ve personally seen two guns ruined this way.

I believe @Gadfly has damaged a personal P320 X Compact this way and there have been two reports of tactical team guys at the agency doing it to full-size guns equipped with the issued magazine wells. If it’s possible on the magazine well equipped guns, it’s probably possible on 17-round frames even without the magazine wells, just because of the taper at the top of the 21rd magazine’s baseplate.

[That Guy]

Beretta PX4 9mm 20 rounders.
Not really extended as such, but the Mec-Gar 9mm High Power 15 rounders have always worked for me.

[1slow]

HK P30 9mm 20 round,
HK USP 45 Solum Tool +3 for 15 total
HK USP 9mm 18 round steel lined, HK 30 round.

[fatdog]

Why would you not trust the TF extensions?

My context is all competition guns (carry optics or limited) so I don't rule out some of it being the gun's fault and not solely the magazine extension. But if I had problems with one at some point I don't trust them for anything but gaming.

1. Failure to lock open/engage the slide stop when empty (frequent and in multiple platforms)
2. Occasional failure to feed on the last round or two
3. Occasional premature slide lock with a round or two left in the mag
4. Occasional follower hang ups on the mag body/extension joint border

[MD7305]

I bought one of these, and it works well in a little shooting, so I ordered two more today.

One distinction is that it is not an extension, the magazine body is full length, and the plastic that looks like an extension is actually a floorplate that shrouds the bottom of the magazine on the front and sides. So even though I have not done a ton with one, the concept seems trustworthy to me, more so than something that is tacked on.

My plan for the three of them is set one up in my JMCK AIWB mag pouch, set so the mag will go low and leave the "extension" poking out to grab.
Another one will get loaded for my nightstand gun, and the remaining one will ride in the range bag and will get used if a 3gun stage looks like it could be a high round count, like an MGM Spinner or something.

I bought 3 of these at the beginning of the summer. So far I've ran them through a Sage Dynamics class, a couple multiple day work related trainings, and various personal range days. I can't really estimate a total round count, probably 2-3k rounds? The mags have been flawless. I plan to get more and further evaluate them.

[JonInWA]

I'm not a huge mega-capacity verging on crew-served weapon kinda guy. Which is good for me, as Washington is not a 10 round capacity limit state...

I've had excellent results with Mec-Gar's plus 1/2 extended basepad with my .40 High Power (especially nice for IDPA, where I can start out at 11 rounds with a given magazine, instead of having to load initially with a Barney magazine, and then switch to a 10 rounder).

Due in large part to the new (July 2022) Washington capacity limitations, most of my platforms are now being run in my matches with quality 10 round magazines, since my higher capacity ones are now literally irreplaceable; they're being saved for EDC/duty.

The other school of thought that I subscribe to is that with fewer shots on board, I'm more focussed on shooting well with within the limited capacity constraints-shooting fewer rounds, but shooting them more effectively.

Best, Jon

[Default.mp3]

My context is all competition guns (carry optics or limited) so I don't rule out some of it being the gun's fault and not solely the magazine extension. But if I had problems with one at some point I don't trust them for anything but gaming.

1. Failure to lock open/engage the slide stop when empty (frequent and in multiple platforms)
2. Occasional failure to feed on the last round or two
3. Occasional premature slide lock with a round or two left in the mag
4. Occasional follower hang ups on the mag body/extension joint border

I have not had any issues with my TF extensions through the years that could be directly attributed to them outside of some of the abuses that I've inflicted upon them during competition. Perhaps it would be wise to distinguish which TF extensions you saw issues with, given that they support many guns; I would definitely (and do) trust my TF +5s on my H&K P30/VP9 magazines, both on the standard 15/17 round mags, and on the 20 round magazines, using the appropriate Wolff magazine springs.