No, the Maglula Range Benchloader Magazine Loader is only compatible with .223 and 5.56 and wont work for 6.5 Grendel. However, the speed loader listed below will work with 6.5 Grendel.
https://www.opticsplanet.com/opmod-u-loader-ar15-ak-speed-loader.html
It should work with all magpul as long as they are for 5.56
Maglula does not offer this product for the Mini-14, you would use SL52B:
https://www.opticsplanet.com/maglula-m-16-ar-15-striplula-10-round-mag-loader.html
Mark H.
No, it will not as it's contoured for length and neck of 223/556 rounds.
Yes, it should work with those magazines
Fits and loads all* AR15 / M4 compatible 5.56 x 45 / .223 magazines using no inserts or adjustments.
Loads:
AR15 / M4 USGI (NATO STANAG 4179)
Magpul PMAGs
H&K metal 416 / SA80
SureFire 60 & 100 rd
Beretta AR 70-90
Lancer
Hexmags
Other metal and polymer mags.