I like the repeatable accuracy of my 16” Vmatch with M4 barrel, but I have read several postings suggests that a FF forend is not as durable as a conventional one or a SIR, which seems to add considerable weight (one+ lbs?) over a FF RAS.

Do I loose significant durability with a FF forend such as a FF RAS? Is the SIR that much more durable to justify the added weight?

It all depends on the barrel configuration on your rifle and how much are you willing to go to mount the handguard.

Let's assume you have a post ban barrel with a removable flash hider or a barrel with out any muzzle device.  the FF RAS is your best choice.  it is super strong and light weight.  you will gain accuracy by free floating the gun, but in your case since your gun has the aluminum free float tube from Bush, you will not see any increase in accuracy.  What you will see is added rigidity, lighter weight, more ventilation, machined in 1913 std rail on all four side (not bolt on) and same plain rail from your receiver to the front sight post.  I also like the SIR, it is a nice system, I think their #50 is their best option.  one good thing with the SIR, you can remove the bottom handguard for M203 mounting or for cleaning. SIR is a bit heavier but it about the same or a bit lighter handguard then your V-match free float tube.

If you have a post ban gun with a muzzle device, you are pretty much stuck to the SIR or a RAS2, either system will offer free float, rigidity and light weight.  unless you are willing to send the gun off to a smith to have the muzzle device removed, install the FF RAS and reattach a muzzle device, then  you can go with a FF RAS.

Hope this helps.

I would say the M4 RAS is the worst option (but I do own one just because it is on a fun gun that doesn't really matter.)

The FF ras in my opinion is better than the SIR

but you can do things with a SIR you can't do with a FF RAS :

take off the lower pannel to access the barrel for mounting 203's or just performing maintenance.

you have an undivided top rail which might be nice that is not an option with the FF RAS. This is really only important for mounting reflex sights.

[b]I don't think you will be unhappy with the FF RAS though (and if you wait you might be able to get the URX which will probably be better than both (IE removeable bottom pannel and I think it allows mounting between the rails of the upper and URX.[/b]

I don't think either unit is more sturdy than the other (FF RAS and SIR systems both will flex if you put massive pressure on them (basically abusive loads like 80ft lbs) but in normal use I don't think they move at all.


The sir weighs a lot compared to the FF RAS RAS and RasII.

Actualy my SIR 50 has less wt. foward of the receiver than the RAS 2, and overall wt. is about 1 oz. heavier on my scales.
Good shootin, Jack

3rdtk,

That's great information about the weight.
The Sir system weights only 1 oz. more then
the RAS.

The Predator system would weight less then
the RAS and the SIR systems.

The SIR system becomes
non-free floating once the M203 is mounted to the barrel, and the SIR rails aren't to the
1913 mil-spec picatinny drawings.

Some additional information.
Hope this helps.
Frank

That would be the RAS2, not the RAS. and that is not including the rail that attach to the receiver.  as far as the FF RAS is concern, it is lighter overall.  


Is that at the expense of the thinner wall thickness or more lightning holes drilled?? how are the durability??



You got to be kidding right??  ARMS rail not in compliance with the 1913 standard??  
as far as the M203, how do you plan on mounting that to your handguards??  I see a full tube which precludes the POF handguard from mounting the M203.  If you say the new launcher will mount to rail, that would also hold true for the SIR.  SIR was deign with that in mind.

Thanks for all the great informations folks. Just to make sure I understand everything:
1. FF Ras is more than sufficiently strong
2. FF Ras is lighter than my existing Bush Alum FF forend (16" V Match) which is close to the weight of the SIR.

I have a M4 post ban barrel on it with no muzzle attachment, so installing a FF ras should not be too nasty.

The SIR adds height to the 1913 rail on top - how does a TA11 ACOG work on top of it - does the SIR raise the height of the ACOG?

Yes, the FF RAS is light years more advanced then the Bushmaster FF tube. it is lighter, stronger and the ventilation is much greater.  (sounds like the 6 million dollar man TV show. [:)])  it also offer a same plain rail mounting solution.

The SIR is a bit heavier but it offers a rail interface that stretches from the front sight to the rear sight, compare to the RAS, the FF RAS will have a gap in the middle for the barrel nut. The SIR rail does add more weight and height.  as far as adding a TA11 it is not too high as far as the cheek weld is concern, I have done it before with my TA31 on my SIr equipped Airsoft M4 and New-ARguy set up his Airsoft M4 rifle in the exact same manner.  [;)]

Yep, being able to mount a 203 or clean the underside of the barrel is ALWAYS the first consideration when shopping for a handguard. LOL, You guys are funny.

That is not funny, I plan on getting a DD M203 one day.  it would be nice to know that is possible.

Given that I want to replace the alum FF Forend on my 16" Bush VMatch with a FF RAS, are there different makes of FF Ras and if so, which should I obtain and in any event from where would you recommend obtaining one and/or having it installed?

thanks for all the help

go to [url]www.quarterbore.com[/url] to see the different types of FF RAS, then you can order your FF RAS from [url]www.mstn.biz[/url]

Wes at MSTN is a great guy and he is very knowledgeable on the differnet RAS and their interface ability.  most likely you want the short FF RAS, but a Mid length or long FF RAS will also fit if you have one of those chopped gas block on your Bushmaster V-match.

The FF RAS is super easy to install if you have the right tools.  Perhaps 30 min in the garage if everything goes well.  If you dont want to get the tools let MSTN do it or send it off to Kurt Wala of KKF in the industry section.  I installed my own but it will have to be removed and reinstalled by Kurt for other work I am having done.

Frank, in what way specifically, are they out of spec?