I RECENTLY ...used all 3 Tapco 30 rd'ers that I got 2yrs ago . no hiccups or ftf. ------1 BLACK,1 FDE , 1ODG. ----THEY'RE NOT built for anything but 55gr. ( or lighter50&45) GUNS&AMMO ,TV GUY ; used them alot on the AR's , ON THE SHOWS; so at 14 bucks each..... WTH.
If you can find the old Thermold magazine's for the Mini-14. They work great. I own 9 of them and never had an issue one with any of them. Other then the old Thermold's for the Mini-14, factory is the way to go.
For the Mini-30, I just picked up 4-20 rd factory magazines. NICE! There is no movement at all to the magzine after its locked up in the mag well. Unlike the 30 rd magazine's I have (no clue who they are made by, been too long ago) which have a lot of back and forth movement locked in.
With aftermarket magazine's it's hit or miss. Some will work great while others turn into epic fail's. When you buy a magazine, make sure when you buy it, there is a good return policy just in case.
Probability will negate my above statements about TAPCO 30Rd.'ers.[ the more--I-use them] But right now ; those plastic "Buggers" haven't loosened( tight & right) & they look purty good for 15 clams apiece.