Tokyo Marui Recoil M4 Stock Tube Mod To Fit UBR Stock

[pacey]

Hi Guys

Was asked in another thread to do a little write up after doing this.

What is the mod and why does it need to be done?
If you want to run a Magpul UBR stock on recoil M4 you will have to do this, the stock tube on the recoil M4 is designed to house the recoil unit and main spring so neither the AEG or GBBR tube that comes with the PTS UBR stock kit will will work.

This leave you having to use the original.

So things you need to know before doing this mod:
Its permanent
You really do need to front wire
Can't be done with cheap tools, you will need access to mill and lathe
You will need an M6 tap

The Recoil stock tube is shorter than the PTS ones.

So here we go, this is what I did an had done for me.

As stated above you will need to front wire the gearbox, as luck would have it you have to strip the stock tube of to do this.

The stock tube needs to be fully stripped, next you either need to have the above tooling in which case I won't tell you how to suck eggs on using it, or take the tube along with one of the new ones from your PTS set to your friendly machine shop.
Now I had my tube milled up to the locking ring threads as I wanted to retain this feature to keep my ASAP plate in place. Plus I do not believe removing them will add any benefit.

This video shows the process quite nicely http://vimeo.com/32142942

Once done it should look the this


You will now be able to slide the UBR mount on to the tube, you will notice straight away it over hangs the end of the stock tube.
I have found a 1inch countersunk M6 bolt works perfectly.

You will need to drill out the end cap and tap it with an M6 tap, when doing this you will notice a lug on the inside of the cap will break off/start to break off. Don't worry you will get about 3 perfect turns which is more than enough to hold the UBR mount on. Take great care doing this, the cap is made of a very light alloy.

From here onwards you are done, unless you want to run and ASAP plate in which case you need to get busy with a file.



Hope it helps

[PureSilver]

Re: Tokyo Marui Recoil M4 Stock Tube Mod To Fit UBR Stock

Thankyou very much - that's very helpful! I'm afraid the attachments don't work, but I think I got the general gist of it and that's more than enough to confirm what I thought.

Interestingly, the ARS (Airsoft Research Syndicate) replacement buffer tube for AR-15 Recoil Shocks (which I have in front of me) includes a new tailcap, which already has a hole drilled and tapped in it in addition to being made of billet CNC'd aluminium alloy. It would be interesting if that tailcap was compatible with fixed stocks and stocks using the same attachment system (like the UBR), wouldn't it! I suspect it is - and it can, of course, be bought separately if anyone would like to try it...

[pacey]

Re: Tokyo Marui Recoil M4 Stock Tube Mod To Fit UBR Stock

Odd those images aren't working. They work for me, here they are again.

IMG_1560.jpgUBRmount.jpg

[PureSilver]

Re: Tokyo Marui Recoil M4 Stock Tube Mod To Fit UBR Stock

Those work just fine - cheers!