For those of you running a Handl lower with gen 3 pmags, do you have any issues at all with them? I heard something about the thickness of the mag giving some problems. All mine are gen 2, but I'd like to buy more.

i have a very early handl lower.  it had tons of issues and had to be sent back.  the one i got back needed a bit more work on a milling machine to fit a giesselle super scar trigger.  since then its been 100% reliable.  i have one gen3 pmag rest are earlier.  dont have issues with any of them.   i did modify my bolt stop to work with pmags and other sr10 type mags.

i have not had a single stoppage in my scar17 in the 5 years or so ive owned it.  95% of the rounds ive fired has been using the handl lower.  no issues with any pmags.  i have used mine for deer hog javelina coyote and antelope along with range target practice.

handl lowers are good just be aware there may or may not be fitment issues with some aftermarket triggers and with excessive wear on the bolt stop from pmag/sr10 if yours exhibits the stop being raised prematurely with just one round in the mag.  all i did was file the catch a teensy bit and recheck with one round in the mag until it stopped raising up.  repeat as needed.

this issue is not an isue with the handl lower but a result of the pmag last round hold open higher than oem mags.  basically an effect of magazine geometry.  its an easy fix if you dont mind modding a part or your mags.  i have a spare bolt hold open in my parts bin in case i ever want to run the oem lower again.

you could just buy one and see how it works.