What gives? 14mm CCW doesn't fit 14 CCW

[Animalmother]

I have a Madbull 14mm CCW and a G&G SS-100 CCW none fit on my Deepfire M4 which is 14mm CCW. The only things that fit are my King Arms Noveske KX3 14mm CCW Flash Hider and my stock Flash Hider...

WHat gives?

The Madbull flashider will screw on then it gets really tight 10% of the way down, I don't want to turn it to hard it'll strip. It's a bit dirty but I dunnu, any suggestions???

[Drake]

I have a Madbull KX3 (14mm CCW) that fits KA and TM (they also fit Guarder and KA) so I'd hazard a guess maybe the Deepfire's threading is slightly off, or something is just a tad snug.

If the KA fits, it can't be that far off; what I would do is apply white lithium grease to the threads in case it's just binding because the fit is slightly snug (frequently happens to me screwing in KA barrel nuts/delta rings on G&P bodies), and do apply a bit of extra force. Like I said, if the KA fits it can't be horribly off spec; I think reasonable force is okay to use here. You will wear off material/otherwise tap slightly different threads, but I don't think it'll be disastrous.

[Animalmother]

I got it on, there was a thread nut stuck in it lol. I don't know why i didnt see it before