I haven't seen this question asked, so here goes...

[Magic_Salad0892]

After seeing a few side by side Walther P99, and PPQ barrels look pretty much the same.

Can they be used interchangably? Or are there dimentional differences?

[Army Chief]

I'm hearing/reading that they may be interchangeable in a pinch, but there ARE clear differences. IIRC, these are most pronounced in the feed ramp area, which explains why there are also differences between the heights of P99 and PPQ magazines near the feed lips.

AC

[Magic_Salad0892]

I'm hearing/reading that they may be interchangeable in a pinch, but there ARE clear differences. IIRC, these are most pronounced in the feed ramp area, which explains why there are also differences between the heights of P99 and PPQ magazines near the feed lips.

AC

Okay that makes sense. So long term use wouldn't be ideal.

Do you think a P99 barrel + P99 magazines = good feed ramp geometry?

[Army Chief]

Okay that makes sense. So long term use wouldn't be ideal.

Do you think a P99 barrel + P99 magazines = good feed ramp geometry?

I don't necessarily see it that way, but some don't see a significant issue. Check out this thread on Walther forums for a bit more info: http://www.waltherforums.com/forum/p99/24218-barrel-swap-p99-ppq.html. I believe there are a couple of others out there that deal more with magazine differences, as well. Plenty of folks are making the comparison for obvious reasons.

While the similarities are obvious, there is no escaping the conclusion that Walther's engineers made some fairly deliberate changes; some we likely understand completely, and others we probably aren't seeing at all. Hot swapping components might seem like a good enough idea from an operator perspective, but you're introducing a whole series of unknowns into the equation by doing this, and if/when one of them results in damage to the gun (or to the shooter), you'll be out on your own without any factory support. I suspect guys will do it anyway, and then show up on the internet complaining that the pistol is failing them somehow.

We're already seeing this to some degree from the guys who don't want to ante up for PPQ magazines, and are doggedly trying to get their old P99 magazines to work (with varying results). They are also the shooters who are going to show up with complaints about feed PPQ issues from "factory mags" -- and who will probably never divulge that they were actually using Magnum Research Baby Eagle mags because "they are the exact same thing." Really?

For my part, I stick very close factory PPQ components across-the-board, so as not to introduce any margin of error in the interest of testing out a good idea or trying to save a few bucks. The price of entry on these guns is more than reasonable, and if one staggers his purchases over time, it is easy to build up a nice supply of OEM mags without resorting to sketchy work-arounds. I'm already up to seven or eight, and the wife hasn't protested one bit. ;)

AC

[balance]

I think Army Chief has the best idea, to keep the pistols as close to stock as possible to ensure reliable function. I can't think of many good reasons to swap a barrel from one pistol into another. There is also a chance that mechanical accuracy may suffer when using the barrel of one 99-series pistol in another.

In this G&A review, the author stated that Walther employees select the best barrel available, as far as fit, to each slide while the pistol is being assembled:

http://www.gunsandammo.com/reviews/new-wave-walther-walther-ppq-review/


One of the attributes of computer-controlled machining is that you can make parts to exacting precision and not have to hand-fit them. Well, Walther takes that a step further. I watched one of the assemblers, sitting at his bench with a bin of slides on one side and a bin of barrels on the other. He would snatch out a slide, grab a barrel and check for fit. If he didn’t like the way it would pop in and out of battery, he’d pull it out of the slide and set it on his bench. (He was careful to set barrels down ranked according to fits.) He’d try another, or a barrel off the bench, until he had one fitting the way he liked. Then he’d put that assembled slide and barrel on a frame and check striker movement with a special gauge. After adjusting things, he’d then cycle and dry-fire it until it felt “proper.” Then, and only then, would it go into the “done” rack.

That being said, if I chose to get a threaded barrel for either my P99 or PPQ, I, personally, wouldn't have an issue using it in the other pistol as well.

There are a few differences that were pointed out in the linked thread in the previous post. Another that wasn't mentioned, was that sometime around 2009, Walther switched from using tapered 9mm chambers to stepped 9mm chambers in all of their polymer 9mm pistols (P99, PPS, PPQ).

[Magic_Salad0892]

Thanks for responding, you guys. I don't own a PPQ, but my girlfriend has been looking for a new CCW, and may be willing to offload her HK guns. (2 P2000s, and a P7M8.... I highly doubt she'll shitcan the P7...)

I'd pretty much never flip a P99 barrel into a PPQ, but I was just wondering if it'd be reliable, or more reliable if you used P99 magazines with it.

However, PPQ barrels, and mags are obviously going to be the most (and uber) reliable. It was just curiosity, and I know it's a question that'll come up eventually.

I'm thinking we may need more Walther technical threads, as if we have them this pistol may gain more popularity, due to the information flow and knowledge base. Especially if we can get members here to really crank some heavy round counts out.

I wrote that like shit, but you guys know what I'm getting at.