STI 10-round 2011 mag question

[zzt]

I received this mag with a used 2011 I purchased.  I've never seen one with the crimps and slits before.  What is the purpose of the slits that go almost completely around the mag?

[Aircooled6racer]

Hello: I think the slits are added before to give some extra allowance for the crimp that they added for the 10 round limit. Thanks, Eric

[waktasz]

So it breaks after 6 months and you have to buy a new one

[KrymSIX]

Hhhmmm, I'll have to check my mags when I get home but I'm pretty sure they do not have the slits. Certainly does seem like that would effect durability. 

[stage12m]

hmm I have never seen that before, curious why. Eric's reply sounds logical for the crimps but not very logical if you want your mag to last for anytime before snapping in two.

[Bullets]

I have a few 10rd mags and they look nothing like that. Mine have deep grooves running top to bottom. It basically just makes it a single stack mag that fits into the double stack grip.  I'm wondering if someone modified that magazine to only accept 10 rounds. I think the state's that have magazine limitations people modify high capacity mags to make them legal. Pretty sure the laws say that the mag can't be able to go back to a high capacity magazine. So basically they have to be modified in a way that you would destroy the magazine if you tried to make it a high capacity again. I'm wondering if that's why those slits are cut in it.

[caspian guy]

I believe that is how in the bad old days of nation wide mag capacity restrictions sti used to make 10 round mags. I have one somewhere that looks like that, it came with a factory edge if i remember correctly.

[Ming the Merciless]

13 hours ago, Bullets said:

 So basically they have to be modified in a way that you would destroy the magazine if you tried to make it a high capacity again. I'm wondering if that's why those slits are cut in it.

 

Yes, the slits are there to prevent the crimped indentations from being pressed flat allowing full magazine capacity.  The slits are supposed to spread apart when the indentations are pressed flat.

[Edge40]

I just picked one up on here recently for really cheap. It's identical to that. Def no way to modify it back to standard capacity with the slits in it. I've never seen one like that before that either. 

[Trini]

It is probably an older 10 rd mag.  Had my 2011 built in early 2000 and frame came with a 10 rd mag.

[darkvibe]

Only guessing but it's probably so if someone cuts or drills out the crimp the mag becomes unusable. Prevents it from being converted to a regular capacity mag.