I recently purchased a rock river arms entry operator 2. It’s a great rifle and I haven’t had any problems with it except for the weight. So now I’ve decided to replace the free float handguard with a magpul MOE handguard. Has anyone ever done this and if you have what parts/tools do I need?
One of my AR’s is a :eek:Double Star. It too has a free float tube and is heavy. As I understand it (limited), you need to replace the low profile gas block with a Front Site Base (FSB)to utilize the Magpul MOE handguard, as the Magpul requires a standard front site. As far as technicality, Im not sure if gas blocks are usually pinned to the barrel or just held in place by screws, so that could be an issue if your gas block is pinned and not to the same spec of a standard FSB. For tools you need a special tool to remove the handguard. Rock River may sell one specific to the free float tube, or one may be available at at an online retailer.
Hope this at least points you in the right direction. FWIW, I also have a BCM Mid-Length with Magpul handguard and it is very light compared to my Double Star. My Double Star was bought used and has a shaved FSB, so I might still take it apart and use it to learn building/modifying.
EDIT: Here is a link to my short thread asking similar http://m4carbine.net/showthread.php?t=71206 You would also need a delta ring assembly.
The rail itself should be pretty straightforward on removing - allen screws or a locking ring of some kind. Once you have the rail off, look at the barrel nut. I don’t know if RRA uses a special barrel nut or not, most of the big name ff rail makers use proprietary barrel nuts and require their own wrench.
You’ll also need to remove the muzzle brake to slip the gas block off the barrel. Is your gas block pinned or set screwed?
Like Kinberfan said, you’ll need a fixed fsb to mount the MOE handguard. Unless you’re a machinist you can’t install the fixed FSB yourself. Look up ADCO, they can pin a new, fixed fsb and I believe the going rate is $90. Since you most likely will have to send it out anyway, I would ask what the extra cost of having everything done would be.
This is going to be tough love.
Have you run it hard in a high round count class? Is the castle nut staked? How is the staking on the carrier key? F/A BCG? Chamber true 5.56? RRA is not a Tier 1 rifle. However, that doesn’t mean you can’t make it better. May be a good idea to replace the BCG with one from BCM. Make sure the staking is correct. Both will go a long way in helping to reduce the probability of issues that RRA is known to have. Having the chamber reamed is insurance also. All of this is predicated on this being a rifle that you may have to defend your life, or that of your loved ones, with. If it is just to punch paper, then you could do without.
A good carbine class, or five, will also help you to get the most from any rifle.
As far as replacing the rail, buy it, have it sent to Robb Jensen, send the upper to him, and let him perform second to none work on it. Plenty of guys on this site can vouch for him.
I believe that the RRA carbine you have uses some type of rail made by YHM. From what I have seen it uses that round jam nut and a proprietary barrel nut. You will need a YHM wrench.
I will caution you that they can be very diificult to remove and you may end up screwing that nut up. I had some that had been put on with some type of adhesive and tightened by a 500 lb. gorilla so I had to cut them off.
You will need a YHM forearm wrench (32.00) plus you will need the various blocks to secure it into a vise. You are also going to need a completely new barrel assembly. In the end you may end up spending more time and effort than it’s worth and you would be better off selling the complete upper and getting something better.
Curious, why a new barrel assembly?
Because he wants or will need an FSB. So you buy a barrel stripped and you need an FSB and then it will need to be pinned into place.
I don’t believe that an MOE will be compatible with that set up. I’m not 100% sure without seeing some close up pics. In any case it is going to probably be more of a headache then it’s worth. IMO YMMV.
Trust me, you don’t want to change free float handguards to handguards that aren’t free float.
Why not? If it doesn’t suit his needs, he most certainly should change it. Granted, his current setup will make the change more difficult and expensive, but to to say “you don’t want to do it” doesn’t make sense.
Gunz, why can’t he have a fixed fsb pinned to the barrel he already has once the lo-pro gas block is removed? If its attached with a set screw I don’t how there would be any problems. If the low pro block was pinned, the only issue I can think of is if that slot overlapped the new ones that would be drilled.
I am just speculating as I am not sure how it is slapped together. I also wouldn’t waste all the time and effort on doing this with a 1/9 twist chrome moly barrel.
Doesn’t make any sense to me. But, it’s not my AR.
For the same reason I don’t remove the front wheel drive from my Z71 LTZ truck. It would be a lot of work and there’s lots of people willing to trade me what they have for what I have, because what I have is better.
Not everyone wants/needs a 4x4. Not everyone wants/needs a FF handguard. Because you think its better does not make it better for everyone else.
If you are somewhat DIY but don’t have the right tools needed for disassembling/assembling an upper, look into the cost of the parts + tools needed vs the cost of the parts + services needed, and go from there. If DIY isn’t your thing, consider the cost of the parts + services to re-do your upper vs the cost of a new complete upper, and go from there.
If it were me (and it sort of was not too long ago), I’d look into acquiring or assembling a second complete upper; especially if I mostly like/enjoy the current upper/rifle. My thinking is that an extra complete upper is potentially more useful to me that a box containing miscellaneous parts.
Edit: If you do opt to keep your original FF upper and obtain a second upper with MOE handguards, you can take both of them with you when you shoot, and decide for yourself what you like/need/prefer.