Mack

All three of those are a pile of wank, dont waste your money. Get a G&G combat machine.

It's just an M4, an M733 doesn't have a flat top upper

OK. Once again everyone is missing the point. The OP wants to know what he needs to have a shorter outer barrel on a Raider Long.
 
This video is for putting a shorter barrel on a standard CQC length Raider but the principle should be the same:

 
Then you're going to need to buy your new outer barrel, i would suggest a 10.5" one which will still allow you to re-use the existing front sight post. After that you're going to need a new inner barrel of the correct length (should be 300mm). Most aftermarket inner barrels are going to be tight bores so look for something as per the suggestions above which is a 6.03mm inside diameter. (check AK2M4.co.uk for these).
Then you'll need to fit it (best doing this while the gun's apart for changing the outer)

 
Then you'll need to post pictures here so we can all tell you what a wonderful job you've done/how to make it work again

This, I yelp like a bitch when a beeb hits the muffin tops

This, I yelp like a bitch when a beeb hits the muffin tops

One from saturday
 

One from saturday
 

What really hurts is being shot on the love handles

One from saturday
 

One from saturday
 

One from saturday
 

One from saturday
 

One from saturday
 

One from saturday
 

Pete @ Ak2m4 will have everything you need to get back up and running, Id suggest firing him a PM on here
 
http://www.ak2m4.co.uk/index.php?route=common/home

copy/paste from elsewhere
 
I Preordered this gun from AirsoftGI so I have had it in my possession for quite some time. I bought it for just the stock and was just looking to drop my already built vsr10 system into it.
 
So from my observations the only things that are not vsr10 compatible are the hopup mounting block, some mag catches(Not the mag release button the actual catch compared to the newer model 2013 and beyond jg bar 10s), and the trigger guard. The rest LOOKS to be compatible with standard parts but I have not tried to mix and match parts as I tossed the internals. You can however with heavy modification use vsr10 trigger guards, hopup mounting blocks and mag catches depending on your skill level.
 
Quality is about JG level overall. The stock itself is excellent being some sort of fiber composite using what I believe to be abs plastic (Similar to the jg cream colored piston) however the saddle cheek rest needs some work in order to hold its position. The externals seem to be decent aluminum and the casting of these parts was much better then that of jgs along with fit and finish. Internally aside from the hopup chamber it should be gutted due to material choices and tolerances. Aluminum cylinder/cylinder head, standard plastic piston, and spring guide with a m120ish 7mm style spring, typical crappy 45 degree trigger system, barrel was uncoated aluminum, bucking is glued in the chamber.
 
However an important note is that depending on how far you are looking to gut it you can face compatibility issues. I was dropping in all pdi externals and primarily pdi internals and the mounting holes do not line up requiring the area that holds the rear tang to be elongated. This required the rear mounting screw hole to be elongated and extensive work to get the trigger guard screw to work properly. I also had to deal with the stock being off spec not allowing the barrel and receiver to drop down in place which some sanding of the channel fixed that. Making an angel custom trigger guard work with this stock required a long process with a dremel.
 
So its completely doable to drop a full pdi rifle into the stock but it will require a lot of time and effort. Simply using it as a base gun and replacing the internals should be more straight forward.
 
Some extra notes are it comes in a semi matte color, slings mounts freely swivel, has standard vsr10 bull barrel.

The real rifle is called the FN herstal SPR A5M. Its military designation is the M40A5. Im guessing the VSR is in there because its VSR compatiable.

Will do, just ordered
 
FMA Maritime
Dummy Sapi's

copy/paste from elsewhere
 
I Preordered this gun from AirsoftGI so I have had it in my possession for quite some time. I bought it for just the stock and was just looking to drop my already built vsr10 system into it.
 
So from my observations the only things that are not vsr10 compatible are the hopup mounting block, some mag catches(Not the mag release button the actual catch compared to the newer model 2013 and beyond jg bar 10s), and the trigger guard. The rest LOOKS to be compatible with standard parts but I have not tried to mix and match parts as I tossed the internals. You can however with heavy modification use vsr10 trigger guards, hopup mounting blocks and mag catches depending on your skill level.
 
Quality is about JG level overall. The stock itself is excellent being some sort of fiber composite using what I believe to be abs plastic (Similar to the jg cream colored piston) however the saddle cheek rest needs some work in order to hold its position. The externals seem to be decent aluminum and the casting of these parts was much better then that of jgs along with fit and finish. Internally aside from the hopup chamber it should be gutted due to material choices and tolerances. Aluminum cylinder/cylinder head, standard plastic piston, and spring guide with a m120ish 7mm style spring, typical crappy 45 degree trigger system, barrel was uncoated aluminum, bucking is glued in the chamber.
 
However an important note is that depending on how far you are looking to gut it you can face compatibility issues. I was dropping in all pdi externals and primarily pdi internals and the mounting holes do not line up requiring the area that holds the rear tang to be elongated. This required the rear mounting screw hole to be elongated and extensive work to get the trigger guard screw to work properly. I also had to deal with the stock being off spec not allowing the barrel and receiver to drop down in place which some sanding of the channel fixed that. Making an angel custom trigger guard work with this stock required a long process with a dremel.
 
So its completely doable to drop a full pdi rifle into the stock but it will require a lot of time and effort. Simply using it as a base gun and replacing the internals should be more straight forward.
 
Some extra notes are it comes in a semi matte color, slings mounts freely swivel, has standard vsr10 bull barrel.

The real rifle is called the FN herstal SPR A5M. Its military designation is the M40A5. Im guessing the VSR is in there because its VSR compatiable.

The real rifle is called the FN herstal SPR A5M. Its military designation is the M40A5. Im guessing the VSR is in there because its VSR compatiable.

Please stop punting out hearsay and opinions as facts.
 
The best mags are whatever feeds reliably in your own gun and fit your budget. Pmags don't work for everyone. MAG 190 round metal m4 magazines are very good, but not necessarily the same goes for everything they do. I've had very good results from dytac invader mags, others have had nothing but grief from them. Also, ASG flash mags are just rebranded Lonex ones.

Will do, just ordered
 
FMA Maritime
Dummy Sapi's

Prommy Purple hop rubber
Element H nub
ZCI 6.02 363mm barrel (Thanks to Pete @ AK2M4)

Let us know how the ZCI barrel works out, Mack, please?