Wondering how reliable the magguts are for the shield 7 and 8 round mags? Anybody have any positive or negative issues?

Magguts? I wasn't sure what this post was going to be about... I was hoping to find a pile of magazines innards.

See this older related thread :
MagGuts for Shield

There are a few threads, if you do a forum search for MagGuts.
Here's the original thread from a year ago, when they first came out.
M&P shield owners, check it out
I've been using them for almost a Year now (since the start of that thread I posted). I gave them a good workout before trusting them in my carry mags and have yet to experience a malfunction due to the MagGuts spring sets.

When installed correctly, they are very reliable, the last round (Now the 8th or 9th round) loads very easily and you can insert/lock the mag with a relatively light push (as opposed to needing to slam it in). If after being installed, the last round is really tight, and the mag is hard to insert/lock, something went wrong. Take it apart and try again.

Yeah... They're $25 a set, but I feel it's worth it.

I know this is a shock, but here is a direct answer to your question: I have fired 800 rounds through my 7 and 8 round mags (about 400 each ) , with zero failures to feed. I am a little old and I needed to buy a maglula also to get 8 into a 7 shot mag after and 9 in the 8 after. that went on for about 10 reloads, now I can do it by hand but the loader is much faster so I still use it.

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Regards from THE Old Fart