10mm Single Stack Capacity

[.455_Hunter]

The Smith & Wesson 10XX guns utilize a 9 round single-stack magazine. The 45XX guns utilize an 8 round single-stack magazine. This all makes sense, given the smaller cartridge diameter.

Current production .45 guns, like the P220 and the 1911, most commonly utilize an 8 round magazine, usually with a slightly extended plastic base plate.

Why do the equivalent 10mm guns only offer 8 round capacity magazines instead of 9 like the original S&Ws?

 

[JTQ]

At least in the 1911 world, 9 round 10mm mags are fairly common

Wilson Combat 10mm 9 round mag https://shopwilsoncombat.com/1911-M...e-9-Round-Standard-Base-Pad/productinfo/47NX/

Tripp Research 10mm 9 round mag https://www.trippresearchinc.com/9r-10mm-rg/

CheckMate 10mm 9 round mag https://www.topgunsupply.com/check-...ll-size-1911-magazine-removable-base-pad.html

Remember, the "standard" capacity of a single stack 1911 in .45 Auto is 7 rounds, as was the original capacity of the SIG P220 in .45 Auto.

 

[.455_Hunter]

Remember, the "standard" capacity of a single stack 1911 in .45 Auto is 7 rounds, as was the original capacity of the SIG P220 in .45 Auto.

Yes- Those were the metal base plate magazines. I am comparing the more "modern" plastic base plate styles that usually offer 8 rounds of .45 in the 45XX, 1911 and P220. It seems like 9 in the current P220 would make sense. What are they doing with the extra ~.400 of space? What trick did S&W have up their sleeve?

 

[JTQ]

What trick did S&W have up their sleeve?

I don't know much about the P220, but if you're comparing a 1911 to an S&W 4506, the difference is the S&W 4506 mag tube is longer. The 1911 and SIG P220 started as 7 rounders, but the S&W 4506 began life as an 8 rounder with the longer mag, in a longer grip. The early 8 round 1911 mags, were merely the same tube as the 7 round mags, with a modified spring and follower to squeeze and extra round in the mag, and it wasn't always successful.

My 4506 mag is 3/8" longer than a CMC Power Mag in .45 Auto. A Power Mag isn't a flush 1911 mag, even without a bumper pad, but it isn't as long as the newer extended tube 1911 mags, but as I mentioned above, CheckMate, Wilson, and Tripp all offer 9 round 10mm 1911 mags.

Also remember, until fairly recently, SIG P226's (like the Beretta 92) had mag capacities of 15 rounds (I think the Legion models still have 15 rounders), before raising them to 17 or 18. Perhaps SIG is more concerned with reliable function in their P220 10mm mags than capacity, or perhaps it just isn't that big of seller, and they don't have much desire to chase the engineering for the extra round.