Myself and the youtuber Coyote Works both bought these Mags and put them in our 17rd models and both had the same result... They were very hard to get in.... I used my 15rd model and the mag went in much better... after putting the magazine about 10 times into my 15rd model, I was able to tightly mind you, get the mag into my 17rd model.... Weird aye! Just be aware.