The "magical" 17 rounds...

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Skribs

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Looking at most 9mm double-stack "full"-size handguns, I notice the majority of them have 15-17 round capacities, most of them right at 17 rounds. There are only 3 that I know of that have more - the Para double-stack 1911 in 9mm (P18-9 or something like that), the Caracal, and the XDm.

What is so special about these three, that don't seem to be much bigger at all than the 17-round conglomerate, that they have 18 (or even 19) rounds?
 
Hmmm?

Just off the top of my head, it is because the mags have steel body's.

The Glock and others use plastic with a steel liner for stiffness.

And they are thicker walled, so take up more room which could have been used for cartridges in a thinner wall steel mag.

But thats just a WAG.

An interesting point is the Browning P35 High-Power only had a 13 round capacity.
That was done so the magazines could be left loaded indefinitely with no risk of over-compression weakening the spring.

The same cannot be said of the 17 & higher capacity mags that use over-compressed springs.

rc
 
It's just always seemed so arbitrary. I'm a bit OCD, I like multiples of 5. A prime number as the "standard" just seems very weird.
 
It is an evolution.

The Hi-Power was, for the most part, the capacity king for many years at 13 rounds. Then came the Beretta 92 and everybody made guns with mags with 15 rounds. Next was the Glock 17 and 17 became the number. You could put more rounds in, but at some point the grip becomes impractically long.

The CZ SP-01 comes standard with an 18 round mag, by the way.

http://www.cz-usa.com/products/view/cz-75-sp-01/
 
It is an evolution.

The Hi-Power was, for the most part, the capacity king for many years at 13 rounds. Then came the Beretta 92 and everybody made guns with mags with 15 rounds. Next was the Glock 17 and 17 became the number. You could put more rounds in, but at some point the grip becomes impractically long.

The CZ SP-01 comes standard with an 18 round mag, by the way.

http://www.cz-usa.com/products/view/cz-75-sp-01/
Kinda reminds me of the horsepower wars with car manufacturers. Bigger numbers are a selling point, even if it isn't a significant difference.

It is funny sometimes to see people worry about 1 or 2 rounds, when they're already in the double digits.
 
It is funny sometimes to see people worry about 1 or 2 rounds, when they're already in the double digits.

That "one more" might always be the one you need.

So, we went from 13, to 15, to 17...we've had a 19 on the market for a while now. Why aren't more people making a 19?
 
There are extended buttplates for most popular, modern handguns. These add 2-7 rounds (usually 2-3 in bigger calibers, 3-5 in 9mm) using the existing mag body. So if you want 19 9mm's, just go buy an extended 'plate, and don't load it full. ;)

For pistols often used in competition classes without a 10-round limit, one can usually find followers that allow an extra round or two; often, these followers are finicky about what ammo they'll reliable feed to the gun. You give up a little anti-tilt stability when you make the follower shorter...

There are also a few "double-stack" mags that aren't quite double-stack. My old Browning BDM mags, for instance, are slimmer than most other double-stack mags (to fit in the slimmest hi-cap grip I've ever seen), but they top out at 15.
 
Just off the top of my head, it is because the mags have steel body's.

The Glock and others use plastic with a steel liner for stiffness.

And they are thicker walled, so take up more room which could have been used for cartridges in a thinner wall steel mag.

My M&P9, which holds 17, uses steel-bodied mags.

I suspect that the overall mag length (and, therefore, grip length) of the 18- and 19- round designs is just greater. Hell, you can make a 30-round pistol magazine, as long as you're OK with the length; Glock sells them.
 
I have watched the growing capacities with interest, mostly as it pertains to my Beretta 92FS. I've gone from carrying 2x15 and 2x10 when I was too poor to afford more pre-ban mags, to trying the 17-rounders out, to the latest 18 and 20-round Mec-Gars. All functioned fine, but by the time you've got a 92FS with 20+1 on board, it is awfully heavy.
 
CZbook4.jpg

The SP-01 mags DO hold 18, and some hold 19, but that's with a built in grip extension. The SP-01 also can use the CZ 75 standard 16 round mags, which I use in summertime for more concealability.

Phantomwith16roundmag2.jpg

I like having options, and more ammo gives more options. I think 15-18 is about right for a 9mm auto, as too much more adds more weight than needed. Perhaps the FiveseveN got it right - what is that, 20/30 rounds in a single magazine?:scrutiny:
 
That "one more" might always be the one you need.

So, we went from 13, to 15, to 17...we've had a 19 on the market for a while now. Why aren't more people making a 19?
That's certainly true, but when is enough enough? You've got to draw the line somewhere, or you end up walking around with a 33 rounder sticking out of your Glock. Conceal that :D

I imagine there are a few reasons that you don't see everyone coming out with 19+ round mags. Just shooting in the dark, I would say to fit one or two more rounds into some of these guns without extending the mag (or worse, making the grip longer/wider), they've got to redesign the mag/spring/follower, that may or may not cause reliability or mag spring life issues. I don't know, maybe they just don't figure that it's worth the effort with their current designs so they just let the aftermarket guys like MecGar deal with the problem if people want an extra bullet or two.

I don't even know what Springfield had to do to squeeze 19 rounds into a gun only 0.1" taller than the M&P, so I don't know what it would take for other companies to do the same.
 
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Yeah if they ever do a .30 caliber straight-walled service cartridge I'm guessing they'll have 21-23 rounds in that thing.
 
There are only 3 that I know of that have more - the Para double-stack 1911 in 9mm (P18-9 or something like that), the Caracal, and the XDm.

The full size Tanfolgios built on the large frame (since 2007, IIRC) hold 18 rounds in 9x19mm, 9x21mm and .38 Super.
 
Hmmm?

Just off the top of my head, it is because the mags have steel body's.

The Glock and others use plastic with a steel liner for stiffness.

And they are thicker walled, so take up more room which could have been used for cartridges in a thinner wall steel mag.

But thats just a WAG.

An interesting point is the Browning P35 High-Power only had a 13 round capacity.
That was done so the magazines could be left loaded indefinitely with no risk of over-compression weakening the spring.

The same cannot be said of the 17 & higher capacity mags that use over-compressed springs.


rc

What constitutes an over-compressed spring? How is it determined? Who do you believe uses an 'over-compressed spring'?
 
The magazine capacity race is at least in part about appeasing the machismo of potential buyers. Some buyers want to take their nearly-20-round mags to the range and be able to say, "Mine's bigger than yours."

For the gun buyer who's more focused on the practical aspects of magazine capacity, there is no denying that having more rounds--as long as you can count on them to cycle--gives more options. But there must be a practical limit after which mechanisms suffer reduced reliability.
 
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I'm always amazed at how ga-ga people get over at Glocktalk when the 33rd mags go on sale...

A 33rd magazine sticking out of the bottom of my Glock...

Really ???
 
A 16 round .40 very compact pistol

I carry a Glock 23 .40 caliber stoked with Glock 22 mags. You can purchase a plastic collar to fill the slight gap between the end of the mag and the grip. This gives you a 16 round .40 caliber in the size of the compact Glock 19 in 9mm. I think this combo is pretty much tops for size, round capacity, reliability, ease of carry, cost, re-sale value, ease of maintenance, durability, cost & availability of magazines, etc. etc. And any other parameters you can think of. The cost and availability of magazines is a HUGE plus. You can purchase one of the best mags in the world for 1/2 to 1/3 the price of many other manufactures. Can't have too many mags. Just my opinion. Your mileage may vary.
 
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...by the time you've got a 92FS with 20+1 on board, it is awfully heavy.

I'm with you there. My M&P9 at 17+1 is quite heavy.

I've considered down loading mags on the occasions I carry it, but that's a whole philosophical can o' worms.
 
Carry

Yes, I agree the ammo weight is heavy in the high capacity pistols. I feel it's lighter and at least equal to two 1911's with 7 round mags. Here is a hint on how to carry a slightly heavy pistol. Google "Hidden Tailor belt" - it a rubber belt that has little "knobs/tits". It's designed for Police, Referees, etc. ie anyone doing vigorous activities that wishes to keep their shirt tucked in. The rubber knobs grip the shirt and the "grippyness" of the rubber grips the pants and you can pretty much wrestle alligators and your shirt will stay tucked in.

The "Hidden Tailor belt" has a great advantage, in my opinion and experience, for concealed carry. It helps hold your pants, shirt, AND PISTOL "UP". I wear one every day and have for years. Even though in the summer I wear a loose shirt that is un-tucked. The Hidden Tailor grips my tee shirt and pants and helps support the pistol. In the winter I do tuck my shirt and wear a vest to cover the pistol. I'd be lost without my Hidden Tailor belt. Just my opinion and "your mileage may vary".

Edited: I corrected the orientation of the Hidden Tailor Belt. Works much better if the knobs/tits are toward the shirt. Flat side toward the pants. The HT Belt is a great, simple invention.
 
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Another factor in mag capacity is how gradual or abruptly the mag tapers at the proximal (feed) end. Caracal has a quite short taper.
 
It's a geometry and design thing, human hands tend to fit a certain range of sizes, and pistols tend to be designed with a certain range of grip lengths and widths, and 9mm cartridges aren't particularly large, so it's very easy to fit fifteen rounds into a grip that isn't all that long or wide, and if you have a full size gun that wasn't designed to have a super slim grip, most of them quite easily have space for more than fifteen rounds.

Nobody is really designing pistols strictly for a set number of rounds, it's a byproduct of the design process. A rifle or other type of gun that generally loads elsewhere than the grip will have magazines designed for a specific number of rounds, but for a pistol the grip size and construction of the pistol and magazine determine capacity for the most part.
 
Yes, I agree the ammo weight is heavy in the high capacity pistols. I feel it's lighter and at least equal to two 1911's with 7 round mags. Here is a hint on how to carry a slightly heavy pistol. Google "Hidden Tailor belt" - it a rubber belt that has little "knobs/tits". It's designed for Police, Referees, etc. ie anyone doing vigorous activities that wishes to keep their shirt tucked in. The rubber knobs grip the pants and the "grippyness" of the rubber grips the shirt and you can pretty much wrestle alligators and your shirt will stay tucked in.

The "Hidden Tailor belt" has a great advantage, in my opinion and experience, for concealed carry. It helps hold your pants, shirt, AND PISTOL "UP". I wear one every day and have for years. Even though in the summer I wear a loose shirt that is un-tucked. The Hidden Tailor grips my tee shirt and pants and helps support the pistol. In the winter I do tuck my shirt and wear a vest to cover the pistol. I'd be lost without my Hidden Tailor belt. Just my opinion and "your mileage may vary".
Huh, never heard of such a thing.. cool.
Maybe you could mention this over at "holsters and gear" here so more know about it.. anyway.
 
My Sig P229 holds 18+1 rounds with the Mec-Gar magazine.
My Springfield Armory XD9 service normally holds 16+1 with the stock magazine, but with the Mec-Gar magazine holds 18+1.
I hope this helps. God Bless :)
 
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