Spacers in RAS

[SlvrDragon50]

What are they for?

[davedawg123]

Shims used to line up the rails?

[Tommygunn]

What spacers are we talking about exactly?

[SlvrDragon50]

What do you mean line up the rails.. I only see how the spacers will push the upper rail and flat top rail apart?

 

Tommygunn: In free float systemsq

[mrblah]

not all bodies and barrels are made to the same tolerance. The barrel spacers are used to sandwhich the barrel to the receiver as you tighten the FF locking collar.

 

The funny thing is, I never needed to use spacers on ris/ras kits that came with the spacers, and on the kits that didn't come with spacers, I had to use them. Murphy's law anyone?

[Magsz]

Blah, im in the same boat as you man.

 

Everytime ive had to install any kind of ras kit that came with spacers i either needed them or didnt. Its very strange, some bodies would fit the same ras kit differently.

[Tommygunn]

So, are we talking the about the large 3cm ish washers that are sandwiched between the outer barrel and the receiver?

[SlvrDragon50]

Ah... so is it bad to have too many spacers? And if you dont have enough spacers (or dont use) then the RAS wont stick to the receiver?

[Tommygunn]

SlvrDragon50,

Can you answer my question?

[SlvrDragon50]

Yes.. I dont think one spacer is 3cm though...

[Magsz]

The very thin silver discs that come with the RAS kits.

[Tommygunn]

Right I'll go out on a limb here since I'm not getting a straight answer.

The washers are to get the correct stand-off between the barrel and the upper receiver. This provides you with the ability to tailor how far the barrel nut screws onto the receiver and in so doing fine tune the orientation of the barrel nut and therefore the RAS.

If you have a FF RAS that replicates a Knight's Armament RAS then you should have two pins which slot into the holes in the Barrel nut. These pins engage with the RAS and prevent it from rotating when you do the outside Delta Ring nut up tight. Without these pins it will be very hard, or rather frustrating, to keep the RAS rails centred as you tighten the Delta ring.

The large thin washers, through trial and error, allow the Barrel nut be done up tight so that the holes, pins and RAS itself are square to the upper receiver. Therefore you put on as few or as many as is required to achieve this.

It is quite feasible that you can get away with using none as the receiver and barrel nut threads may be cut just so. However, this is unlikely and you'll probably end up using 2 or 3.

For example on my CA barrel I have 2 to correct the orientation of the Barrel nut and so keep my non FF RAS square when the Barrel nut is done up tight.

[SlvrDragon50]

OHHHH I understand now.. I didnt know about the 2 thick pins though.. Thats nice

 

I use one of those madbull RAS fix thingies anyways so it doenst move.

[Tommygunn]

I know quite a few makers of the kits don't actually include the pins. If you've got some think yourself lucky that you won't be on your hands and knees with the receiver between your legs while you hold the RAS with one hand and do the nut up with the other. A real pain.

[SlvrDragon50]

G&P FTW!

 

So the pins we are talking are the fat ones right?

[Tommygunn]

Fat dumpy things, about 5mm by 10mm. You should have two and you put them left and right or top and bottom and it locks the RAS to the barrel nut and prevents it spinning in relation to the rest of the gun while you do the Delta ring nut up tight.

[SlvrDragon50]

Alright thx!

 

Still gotta solve my gas tube though x.x

[Tommygunn]

What's the problem with the gas tube?

 

p.s. if you've got a gas tube then you won't be able to put a pin in the top of the barrel nut.

[SlvrDragon50]

I cant get the pin to go through the gas tube and block

[Tommygunn]

Nail punch(or nail), but pinch it in with a pair of pliers first.