Corso Inc. is a Florida based company that develops new internal parts (guts) for handgun magazines. The kits are sold under the MagGuts brand name. By swapping out the magazine internals, with the MagGuts replacements, you can add one additional round to the magazine capacity without negatively impacting magazine reliability. Unlike most other products that increase magazine capacity, MagGuts kits are designed to add capacity without changing the overall magazine length. MagGuts offers kits for several different handguns. In addition to the Glock 42 magazine kit reviewed here, they also have kits for most of the popular single stack 380 Auto pocket pistols. Their complete product line can be viewed and ordered on their website.
The Glock 42 MagGuts kit consists of a replacement spring and new follower. These parts are direct replacements for the Glock spring and follower. The kit can be installed in less than a minute if you are familiar with taking apart Glock magazines. If this is your first attempt to remove the base plate from a Glock magazine, it may take you a few minutes longer.
The kit ships with excellent detailed and illustrated instructions. MagGuts has also produced installation videos for all their kits that can be viewed on YouTube or from their website. I've included the MagGuts installation video for the Glock 42 below so you can see how easy it is to install the kit.
I've previously disassembled Glock magazines, so I knew what to expect when pulling the base plate from the magazine. I'm not a big fan of forcing the base plate over the two little locking lugs at the base of the magazine body. In the picture on the left I've placed a red arrow by one of the locking lugs so you can see what I'm referring to. There is a matching lug on the opposite side of the magazine body.
I prefer to use a set of vice-grips that are padded with a piece of scrap kydex to gently squeeze the magazine body directly over the locking lugs. This helps the magazine base plate slide off more easily. This is purely optional, but I wanted to share it with you. If you do use vice-grips, please remember to gently squeeze the magazine body. Applying too much force could crush the body.
As mentioned above, the MagGuts kit allows you to squeeze one more round into the magazine without causing any problems with magazine reliability. I was really pleased to discover that the fully-loaded converted magazine still locked into the magazine well as easily as it did before installing the kit. Magazine feeding and empty magazine activation of the slide lock was flawless with the MagGuts kit installed. Rather than have you take my word for it, I shot a quick video just for the blog to demonstrate shooting the G42 with a stock magazine and with a MagGuts equipped magazine.
After shooting the demonstration video, I sent quite a few more rounds downrange using the MagGuts converted magazine with the G42 loaded to 7+1 capacity. Rain cut my practice session short, but I'm comfortable and confident that the converted magazine can be used as my carry magazine.
The Glock 42 MagGuts kit sells for $17.95 and can be ordered from the MagGuts website. Orders over $25 are shipped free. All MagGuts products are 100% made in the USA. Currently the product line is limited to single stack 380 Auto magazines, but I have a feeling that single stack 9mm kits may be offered in the future. Corso Inc. welcomes your new product requests, so if they don't make a kit for your current concealed carry handgun you can let them know which kit you would like to see them develop in the future.