GBBR RIS length different to AEG?

[runningrabbit]

Hi all,

Have just received the new M4A1 5KU outer Barrel in the post however the triangle sight post sits around 5mm too far away now so the RIS won't hold in place.

Does anyone one if the AGM standard barrel/RIS setup is different from WA standard or have I got to buy a new RIS rail?

Thanks in advance,

Rich

[dave38x]

Re: GBBR RIS length different to AEG?

willing to bet the AGM one uses a cheapo AEG length hand-guard. King arms, G&P and most of the other good makes use a real length handguard I believe. The giveaway is whether a PTS MOE handguard fits.

[runningrabbit]

Re: GBBR RIS length different to AEG?

Is anyone on here able to give the measurement? Mine is 168mm

[dave38x]

Re: GBBR RIS length different to AEG?

the PTS MOE handguard I have in front of me is a gnats hair over 168mm in length from front to rear of interface points.

Suspect if it's 5mm longer than that either the gas block is incorrectly mounted or the barrel assembly is just incorrect somehow.

Do you have any photos of the barrel assembly?

[runningrabbit]

Re: GBBR RIS length different to AEG?

None of the above so it turns out.

Seems the AGM barrel has an exceptionally thick collet when the barrel nut mounts to the reciever. On the 5KU barrel it needed to be shimmed out by 4mm to make it assemble correctly. 1x Madbull Barrel Shim Set later and all is well in my world again.

Thanks for all the suggestions though people.

Rich