DD rail fitting - help needed

[Lozart]

I'm changing my M4 handguard from a standard delta nut and KAC style RIS to a Daniel Defense Mk18 style handguard. It's a chinese clone of the madbull rail by the way.

The problem I'm getting is one similar to something I had when changing the Delta Nut in the first place namely that the barrel nut goes on about half a turn and then binds. It can be forced further but needs way more force than seems reasonable. It's a Dytac receiver and I had this problem with an Element delta nut. I ended up going to a King Arms delta nut as that fitted no problem. I'm wondering if anyone else has had a similar issue and what they did to solve it. It almost feels like the receiver threads aren't cut properly somehow.

Any advice gratefully received!

 

[Mack]

Sounds like the nut is a different threading to the receiver. What I did was cut the spikey teeth of my original barrel nut with a hacksaw and then filled it down.

 

[Lozart]

Yeah, seems g&p receivers are the same. Bought a madbull die this morning. Hopefully that should sort it.

 

[Lozart]

So the Madbull die went over the threads but didn't really take much off. The barrel nut still refuses to go on. I'm assuming this is due to it being a cheap chinese knock off...

Anyone got a Madbull DD barrel nut they want to part company with?

 

[Lozart]

Ah fuck it. TO THE DREMEL!!!!

What's the worst that could happen, eh?

 

[Sitting Duck]

Ah f*ck it. TO THE DREMEL!!!!

What's the worst that could happen, eh?

Your last cutting disc snaps - usually

not anymore - bought a few packs of 20 or so discs - 60+ I got cheapo fleabay SilverLine discs

so even when it snaps as I nearly finish cutting - I think....

Pah - there's plenty more where that came from mofo

(hacksaws - pah I got 59 discs & ain't afraid to use them - crap 58 now)

 

[Lozart]

Your last cutting disc snaps - usually

not anymore - bought a few packs of 20 or so discs - 60+ I got cheapo fleabay SilverLine discs

so even when it snaps as I nearly finish cutting - I think....

Pah - there's plenty more where that came from mofo

(hacksaws - pah I got 59 discs & ain't afraid to use them - crap 58 now)

See...I have two responses here. Firstly I don't buy cheap crap cutting discs off ebay, secondly twenty years of engineering has taught me to be more patient and less ham fisted.

I got the toothy bit cut off last night only to discover that the original barrel nut from my Delta ring is in fact much deeper than the nut from the floating rail. So now I'll be cutting it down as well. Yay.

 

[Sitting Duck]

twenty years of engineering has taught me.......

I got the toothy bit cut off last night.....

Along with

Ah f*ck it. TO THE DREMEL!!!!

What's the worst that could happen, eh?

I have so much still to learn

 

[Lozart]

All perfectly good engineering terms there I'll have you know.

 

[Lozart]

So after much faffing and grinding the barrel nut fits. YAY!

But....

When I went to fit the front sight post back on, it won't go on far enough. Strange I thinks to myself. Out with the taper measure and yep, you guessed it - it's not a 7" rail. It's a 7.5" rail.

Never buy stuff on ebay late at night.

So - ditch the rail? Change the barrel? What say you all?

 

[Mack]

Short barrel and bolt back up iron sights to the rail

 

[Lozart]

Short barrel and bolt back up iron sights to the rail

Considering going for the "Strike back" look - short barrel, lose the iron sights and fit a KAC QD suppressor up to the end of the rail.

Any odea what length barrel I'd need to fit a standard flash hider and be able to get the KAC QD suppressor on? The choice seems to be Madbull Noveske in either 7.5" or 8.5", Dytac UXR 8" or Dytac SBR in 7.5".

This is the kind of thing I mean: