FN Herstal Firearms banner

1 - 20 of 22 Posts

·
Registered
Joined
·
11,157 Posts
Discussion Starter #1
So I am expecting that "TUNA" might be in season later this week in Columbus, OH and in anticipation have read through almost every thread in the FS2K forum for the past several weeks. I understand many owners have decided to send their barrels out to Tornado Technology to have cut down to 14.5", re-crowned, rethreaded and have a new flash hider or muzzle break permanently re-pinned to the 14.5" barrel to still meet both the 16" barrel length requirement and 26" overall length requirement. I also will have interest in having this done but having a surefire SoCom 5.56 flash hider re-pinned to use my SoCom 5.56 can on the FS2000.

But I got to thinking and this is my question that I could not find an answer too in the almost every thread in the FS2K forum that I have previously read:

Is anyone having their barrels cut down shorter than 14.5" and if so what seems to be the new, shortened barrel length that is most desirable?

I am well aware this puts me into ATF/SBR/Tax Stamp territory but if I am going to go through the process of having the barrel cut down, re-crowned, rethreaded and the new flash hider re-pinned I figure why not take an extra inch or two of this thing? The goal here for myself with this set up is to ultimately get the suppressor closer to my body to keep the rifle balanced properly.

Can someone please stop me if my thinking is headed down the wrong path? As always thank you all for your help.
 

·
Registered
Joined
·
1,692 Posts
Buckeye,

While I don't have the FS2K I have always had a hard time understanding why people would go to the expense of cutting down a barrel, re-crowning & re-threading as needed to only go and pin/weld a longer muzzle device to regain legal length when why not spend the 2 franklins and SBR it and have the best of all the worlds....long length when they want with an easily removed muzzle device and nice a short for CQB setups and in your case gain the better balance when adding a suppressor into the mix...

I suggest getting the stamp and then cut that puppy way down and enjoy!
 

·
Registered
Joined
·
11,157 Posts
Discussion Starter #3
I am in agreement with your thinking so if I did go this route I just can't determine what the proper, acceptable functioning barrel length should be....my logic and its probably wrong is that if my 16" SCAR barrel is going to be replaced with a 10" CQB barrel then why couldn't this FS2000 barrel be cut down to the same 10" length as the SCAR CQB barrel?


Buckeye,

While I don't have the FS2K I have always had a hard time understanding why people would go to the expense of cutting down a barrel, re-crowning & re-threading as needed to only go and pin/weld a longer muzzle device to regain legal length when why not spend the 2 franklins and SBR it and have the best of all the worlds....long length when they want with an easily removed muzzle device and nice a short for CQB setups and in your case gain the better balance when adding a suppressor into the mix...

I suggest getting the stamp and then cut that puppy way down and enjoy!
 

·
Registered
Joined
·
3,731 Posts
I've heard that Surefire will not honor warranty on your suppressor if the adapter is pinned and welded. I guess you can just not tell them...

Also I don't get it. I assumed once pinned and welded the barrel plus the flashhider will be 16" or longer (otherwise why would you pin and weld it if you're just going to SBR it?), so why would it put you in the "ATF/SBR/Tax Stamp territory"? The OAL wouldn't be an issue either, since stock is 29.9" and cutting 3" will make it 26.9" which is within NFA minimum for OAL.
 

·
Registered
Joined
·
1,692 Posts
In doing some quick google work it looks like once the standard setup is cutdown into the 14.75" that cycling issues crept up needing the users to use the adverse setting on the gas piston when at 15.75" things were still cycling fine with the standard piston setting. But when they attach their suppressors they go back to the standard pistol setting..
 

·
Registered
Joined
·
1,692 Posts
CPTDaz,

Buckeye would be in NFA stamp territory as the barrel is 17" stock and if he cut the 3 inches off the barrel puts it at 14 which is under the required 16" for GCA rifles even though he would still be over the OAL. GCA rifles require both 26" OAL & 16" barrel or greater lengths
 

·
Registered
Joined
·
3,731 Posts
CPTDaz,

Buckeye would be in NFA stamp territory as the barrel is 17" stock and if he cut the 3 inches off the barrel puts it at 14 which is under the required 16" for GCA rifles even though he would still be over the OAL. GCA rifles require both 26" OAL & 16" barrel or greater lengths
But once he pin and weld a flash hider to make the barrel length 16" then he wouldn't need the stamp. That's the whole point to pinning and welding any muzzle device or so I thought.

Also I think the stock FS2000 barrel length is bit longer than 17" so by taking 3" off he would be around 14.5". I assume 14.5" is the magic number because that's the standard barrel length for M4 (I'm guessing the military has sufficient 556 ballistic testing results to support that length)
 

·
Registered
Joined
·
1,051 Posts
I've considered doing the same thing but there were a couple things that made me change my mind.

1. FS replacement barrels are rare. In all the time I've been lurking here through my signup (2008-now) I think I've seen 2 or 3 go up for sale and they all were all $500+. Now this is only an issue if the people cutting the barrel make a mistake or someone really messes up the pin and weld job.

2. Cutting the barrel voids the warranty. With the rifle out of production I would really hold onto that warranty. If something goes wrong with it and you send it back with the original barrel that's uncut; FNH will most likely just send you a new gun.

If I were you I would just get a Surefire adapter that fits the native threads and call it a day. Sure you loose out on the 1-2in but you haven't permanently altered something that will be permanent.
 

·
Registered
Joined
·
3,731 Posts
Also, not sure about FS2000, but on ARs, pinning and welding muzzle device will prevent you from swapping gas block and barrel nut (unless you cut the muzzle device off). Something else to keep in mind.
 
  • Like
Reactions: BigBuckeyeGuy

·
Registered
Joined
·
1,692 Posts
CPTDaz,

Sorry I must have miss understood what you were saying....You are correct if the flash/muzzle device IS pinned/welded to bring the overall barrel length to 16"+ owners of the FS2k would not need a sbr stamp.... but that again brings me to say WHY go to the expense to cut/re-crown/re-thread and as mentioned void the warranty unless you really want to get into and use the FS2K as an SBR ?
 

·
Registered
Joined
·
3,731 Posts
Yeah, I see your point; it doesn't really make a lot of sense for something like FS2000. But to each his own.

Also, FS2000 is out of production? I thought that was an unconfirmed rumor?
 

·
Registered
Joined
·
11,157 Posts
Discussion Starter #12
CPTdaz,

sorry if I wasn't clear it happens with me a lot. There are 2 scenarios being discussed here. 1. Cut down to 14.5" and re-ping to meet 16" barrel length and 26" overall length. I got that piece although thanks for the info heads up on the surefire flash hider and this issues with pinning that back on. The reason I would do this is because I own the surefire can so if I could get that mileage out of it I would like to but would need to have the barrel rethreaded so I might as well have a little cut down.

But, then I started thinking why not just SBR the FS2K and have the barrel cut down further than 14.5"? But, I just don't know the right cut down length to still provide proper function of this one? If I go this route then yes, no re-pinning of the surefire flash hider and the warranty is good to go. Does this make any more sense or did I run off the track?

I've heard that Surefire will not honor warranty on your suppressor if the adapter is pinned and welded. I guess you can just not tell them...

Also I don't get it. I assumed once pinned and welded the barrel plus the flashhider will be 16" or longer (otherwise why would you pin and weld it if you're just going to SBR it?), so why would it put you in the "ATF/SBR/Tax Stamp territory"? The OAL wouldn't be an issue either, since stock is 29.9" and cutting 3" will make it 26.9" which is within NFA minimum for OAL.
 

·
Registered
Joined
·
3,731 Posts
Oh okay. This was posted here a while back; now is a good time as any to bring it back up: Barrel Length Studies in 5.56mm NATO Weapons
Thus, it is the opinion of the authors that barrel lengths less than 14.5” in this caliber introduce effectiveness issues that may be detrimental to the user.
 

·
Registered
Joined
·
2,246 Posts
I thought you could take off factory flash hider and rethread it 1/2 x 28 and still be long enough to be legal. You would just have a little notch in the side of your barrel where the factory one was once pinned. That's what I would do if possible unlike most folks who chop and pin a muzzle brake. I do not like quick mount suppressors so having to pin something on permenatly would be a negative to me
 

·
Registered
Joined
·
3,731 Posts
Yep anytime.
 

·
Registered
Joined
·
1,850 Posts
I think the real issue is, how much barrel is needed after the gas port to operate the piston. The piston needs a certain amount of pressure and volume to cycle the action reliably. I have no idea how to find that out. The problem is, you cant just chop a barrel down as far as you can still screw a muzzle device on and test. Then remove the gas screw and see if it works. You would need to be able to get a new barrel if it does not work, to go longer for enough pressure.
 
  • Like
Reactions: BigBuckeyeGuy

·
Registered
Joined
·
11,157 Posts
Discussion Starter #19
Technically speaking, yes & thank you - that was/is my question. After much quick deliberation, when my TUNA arrives I will leave the barrel as is!

I think the real issue is, how much barrel is needed after the gas port to operate the piston. The piston needs a certain amount of pressure and volume to cycle the action reliably. I have no idea how to find that out. The problem is, you cant just chop a barrel down as far as you can still screw a muzzle device on and test. Then remove the gas screw and see if it works. You would need to be able to get a new barrel if it does not work, to go longer for enough pressure.
 
1 - 20 of 22 Posts
Top