To clarify, you’re concerned about the cap that’s behind the FSP?

https://youtu.be/qkEK5_Nr8Kc?si=_IJWvKA1r5hRniuo

I found this video on the rail and during the video, it shows the cap. If your gun is setup like the one in this video, how are you burning your hand in the cap? Or is the rail in contact with the cap or the rail itself getting hot?

I just don’t see how your hand is touching the cap. At least in this video it seems inset, or not protruding. Even then, where would you put the fabric? On the rail? If on the rail, I still think you’re better off with a hand stop or G10 or other scale on the top pic section. If you’re going to put the fabric on the cap, won’t it contact the rail?  Thus lose the benefit of free float.

The rail is not getting hot, just the FSP and the exposed portion of the handguard cap, on the top half of the cutout of the guard. I would apply a fabric just to this small portion that is exposed as that is the only portion that I really felt hot. Was hoping a small piece of fabric would solve the problem easy and cheaply. I would be worried that a handguard mounted flip up would not be as accurate as a fixed FSP attached to the barrel. Maybe too miniscule to matter though?

Maybe I will cut it off, its pretty cheap and can put it back on if I ever need to, just have to take off warcomp.

I have thought about cutting off the FSP to make it low profile as well but then I spent extra money on this guard for nothing, could have gotten a more affordable one.

The rail is not getting hot, just the FSP and the exposed portion of the handguard cap, on the top half of the cutout of the guard. I would apply a fabric just to this small portion that is exposed as that is the only portion that I really felt hot. Was hoping a small piece of fabric would solve the problem easy and cheaply. I would be worried that a handguard mounted flip up would not be as accurate as a fixed FSP attached to the barrel. Maybe too miniscule to matter though?

Maybe I will cut it off, its pretty cheap and can put it back on if I ever need to, just have to take off warcomp.

I have thought about cutting off the FSP to make it low profile as well but then I spent extra money on this guard for nothing, could have gotten a more affordable one.

Buy once, cry once.

Quite often the cheap comes out expensive.

I'm sure there's another sucker owner somewhere who'll be glad to take it off your hands.  Whatever you can sell it for will make the new one cheaper.  Sunk costs are sunk for good.  No need to fret over them.

The rail is not getting hot, just the FSP and the exposed portion of the handguard cap, on the top half of the cutout of the guard. I would apply a fabric just to this small portion that is exposed as that is the only portion that I really felt hot. Was hoping a small piece of fabric would solve the problem easy and cheaply. I would be worried that a handguard mounted flip up would not be as accurate as a fixed FSP attached to the barrel. Maybe too miniscule to matter though?

Maybe I will cut it off, its pretty cheap and can put it back on if I ever need to, just have to take off warcomp.

I have thought about cutting off the FSP to make it low profile as well but then I spent extra money on this guard for nothing, could have gotten a more affordable one.

Do you have a RDS as primary on this rifle?  If so, I wouldn't fret it. . .

I have a few ARs free float handguards/rails with low-profile gas blocks.  I haven't noticed any huge difference with the BUIS.  With quality handguards/rails, the lockup should be solid.  Or at least "solid enough".  I don't intend on shooting any rifle matches or anything, but once zero'ed, I haven't noticed anything.  Back when KHSC had steel all over the hillside, it was easy to get consistent hits with irons on those steel in the 200-280ish range. 

Overall, might as well do things right.  Yeah, sucks that you may be out on some $$$ by changing configurations.  You could try a different configuration for a while, but that's even more $$$.  That's what I did, and ended up spending more $$$, but was able to iron out what worked for me. 

...
I would be worried that a handguard mounted flip up would not be as accurate as a fixed FSP attached to the barrel. Maybe too miniscule to matter though?
...

Do you have a RDS as primary on this rifle?  If so, I wouldn't fret it. . .

I don't see the reason to worry.  is your rear "iron" sight attached to the rail above the upper receiver?  What's holding it in place?  My guess it's the same type of screw mechanism that probably holds the front sight in place, too.  if you're worried about one, you should be worried about both.

Maybe you should do a little research, and contact all the AR makers in the country.  Ask them how many of the ARs they sell with free-floated barrels and front sights attached to the handguard rail have ever been reported to be 'less accurate" than a comparable AR with an A2 FSP.

In my opinion, i'd trust a free-floated handguard-mounted front sight just as much as a barrel-mounted A2 FSP.  If you're bumping your barrel into things hard enough to damage or misalign the flip-up front sight, chances are the barrel is taking the brunt of the force -- as the barrel protrudes beyond the end of the a handguard.  The A2 post isn't damage-proof.

From another viewpoint, as DRCK mentioned, if you have a red dot optic installed, then the BUIS are exactly that -- backup sights.  Your primary will always be the optic.  IMO, it's a good idea to use 1/3 co-witness elevation on the optic so you can visually check the iron sights' zero periodically.  All sights are subject to moving if they are shot regularly.  The vibration alone -- outside of any bumping or dropping -- is sometimes enough to loosen screws/mounts. You also have to consider the possibility of accidentally moving the sights' adjustment when handling the weapon.

So, if properly co-witnessed, a quick look to see if the iron sights and red dot are aligned just prior to using them  can be all that's needed to know both are good.  it can also alert you to a misaligned optic that might have been bumped, had mounting screws loosen, and so on.

If you're treating this as a competition rifle and need a 100% accurate zero every single shot, then i'd be more concerned with the heat you're complaining about.  A hot barrel  can definitley affect the accuracy of the gun even if your POA is identical from shot to shot.

Besides my back up sights, I also know other parts of the gun that I can use for short distances and still get on paper as a mcGuyver style of sight.  This includes my pistols.  The theory is if you RDS and back ups break.

I don't see the reason to worry.  is your rear "iron" sight attached to the rail above the upper receiver?  What's holding it in place?  My guess it's the same type of screw mechanism that probably holds the front sight in place, too.  if you're worried about one, you should be worried about both.

SNIP

I am a$$uming he is fretting about the rail moving relative to the receiver. 

I am a$$uming he is fretting about the rail moving relative to the receiver.

When i take the handguard off, I reinstall it by first getting the connection hardware & handguard loosely in place.  Then I put an optic mount directly over the seam between the upper rail and the handguard rail.  Tightening that mount down to both rails makes them flush and perfectly parallel.  Then I tighten the handguard hardware.

So, disassembly/reassembly shouldn't be a concern if done right.

Unless there's a handguard i don't know about, the only way the handguard's rail can move is if the entire handguard moves.  If you're using Lock-tite and proper torque, it'll take some force to cause that thing to move.

I admit the monolithic rail was one of the selling features that sold me on the Colt LE6940.  As my first AR, I didn't have any experience to know any different.  Then i figured out you'd have to be really abusing your rifle to need a single rail along the top.  Over time, I also became less than a fan of the quad rail design.

There's always a compromise. 

If you want a solid steel rifle barrel and FSP, then you probably aren't planning to use it for competition.  You're looking at actual tactical/combat use.  At that point, the original AR carbine handguard with no rail is a good option.  isn't that handguard mostly plastic and a foil type heat shield? 

But, if you want a free-floated barrel for better accuracy and a place to mount accessories, you're more likely looking at it for home defense and/or competition.  That's when a free-floated barrel and light weight aluminum handguard that's longer than carbine length -- giving a longer sight radius -- would allow for better feel, control and accuracy.

I'm not saying a free-floating handguard can't move, but there are things that can be done to prevent it.

If you want your A2 sight, you can keep your A2 sight.   Just don't expect it to offer the same benefits as a "normal" free-floated AR with a handguard-mounted front sight.

Besides my back up sights, I also know other parts of the gun that I can use for short distances and still get on paper as a mcGuyver style of sight.  This includes my pistols.  The theory is if you RDS and back ups break.

Hence the need for 30rd mags!

 

Do you have a RDS as primary on this rifle?  If so, I wouldn't fret it. . .

I have a few ARs free float handguards/rails with low-profile gas blocks.  I haven't noticed any huge difference with the BUIS.  With quality handguards/rails, the lockup should be solid.  Or at least "solid enough".  I don't intend on shooting any rifle matches or anything, but once zero'ed, I haven't noticed anything.  Back when KHSC had steel all over the hillside, it was easy to get consistent hits with irons on those steel in the 200-280ish range. 

Overall, might as well do things right.  Yeah, sucks that you may be out on some $$$ by changing configurations.  You could try a different configuration for a while, but that's even more $$$.  That's what I did, and ended up spending more $$$, but was able to iron out what worked for me.

I have a Trijicon MRO.
I am probably overthinking it.

probably???

I have a Trijicon MRO.
I am probably overthinking it.

SNIP

So, disassembly/reassembly shouldn't be a concern if done right.

Unless there's a handguard i don't know about, the only way the handguard's rail can move is if the entire handguard moves.  If you're using Lock-tite and proper torque, it'll take some force to cause that thing to move.

I was guessing that OP was concerned about the end of the rail/handguard flexing relative to the barrel.  I've seen some cheapo models (UTG and the like) where the lockup isn't tight and there's noticeable movement of the end of the rail.  All of my ARs are solid (BCM, Geissele, and DD).  However, the rail on my friend's AR9 (believe Midwest Industries) does move no matter how much you torque down the "clamp" at the receiver end of the rail. 

I used to have an LMT that had a monolithic rail.  While that sucker was bombproof, but ended up selling it. 

I have a Trijicon MRO.
I am probably overthinking it.

Yup. . .

I was guessing that OP was concerned about the end of the rail/handguard flexing relative to the barrel.  I've seen some cheapo models (UTG and the like) where the lockup isn't tight and there's noticeable movement of the end of the rail.  All of my ARs are solid (BCM, Geissele, and DD).  However, the rail on my friend's AR9 (believe Midwest Industries) does move no matter how much you torque down the "clamp" at the receiver end of the rail. 

I used to have an LMT that had a monolithic rail.  While that sucker was bombproof, but ended up selling it.

The main issue with the Colt I had with the monolithic rail, besides weight and the quad-rail handguard, is you needed a special, proprietary tool from Colt to remove the barrel nut.  I would probably never need to do that, but it's one more hurdle if you need to.

I don't know about the LMT you had, but I've seen many other free-floated handguards that also require you swap out the barrel nut to a proprietary one, and most require a special tool -- although some do allow you to use a standard AR barrel nut wrench.

Since the OP splurged for the Troy handguard already, he should remain in that mindset with a replacement if that's the route he chooses.  If he's worried about the quality of his build, he shouldn't be cheaping out to start with.  Much of the cheap stuff on the market was designed and marketed for airsoft rifles.  Those items just happen to also fit real ARs, but they aren't close to the standards set for manufacturing actual firearm accessories.  Sometimes you can live with cheap for non-critical parts, but for a handguard and front sight, I'd say buy the best you can within a reasonable budget.  What he already spent for the handguard he has was a reasonable amount.

What did your friend do with the AR9?  Depending on how long I'd owned it, I would think contacting the manufacturer would be a good start.  If that model has a defective design, they need to know about it and be given a chance to correct it.  That's not possible on a self-built AR, so it depends on who built the AR9.  If it's his own build, maybe contact the handguard maker to see it there is a fix.  Some companies stand behind their product 100%.

I don't look at firearm parts the same as most stuff I buy.  I expect them to be serviceable and perform as expected.  If I have a problem with a purchase, someone is going to hear about it! 

 

The main issue with the Colt I had with the monolithic rail, besides weight and the quad-rail handguard, is you needed a special, proprietary tool from Colt to remove the barrel nut.  I would probably never need to do that, but it's one more hurdle if you need to.

I don't know about the LMT you had, but I've seen many other free-floated handguards that also require you swap out the barrel nut to a proprietary one, and most require a special tool -- although some do allow you to use a standard AR barrel nut wrench.

Since the OP splurged for the Troy handguard already, he should remain in that mindset with a replacement if that's the route he chooses.  If he's worried about the quality of his build, he shouldn't be cheaping out to start with.  Much of the cheap stuff on the market was designed and marketed for airsoft rifles.  Those items just happen to also fit real ARs, but they aren't close to the standards set for manufacturing actual firearm accessories.  Sometimes you can live with cheap for non-critical parts, but for a handguard and front sight, I'd say buy the best you can within a reasonable budget.  What he already spent for the handguard he has was a reasonable amount.

What did your friend do with the AR9?  Depending on how long I'd owned it, I would think contacting the manufacturer would be a good start.  If that model has a defective design, they need to know about it and be given a chance to correct it.  That's not possible on a self-built AR, so it depends on who built the AR9.  If it's his own build, maybe contact the handguard maker to see it there is a fix.  Some companies stand behind their product 100%.

I don't look at firearm parts the same as most stuff I buy.  I expect them to be serviceable and perform as expected.  If I have a problem with a purchase, someone is going to hear about it! 

 

The LMT was MRP.  It had a pretty neat barrel lockup, and was multi-caliber capable.  Just needed a torque wrench, which was provided with the gun, with sort of a clamping action on the side of the receiver.  I just checked and the complete uppers are going for more than what I bought the complete gun for. 

No idea what my friend did with the AR9. 

Excellent video. 

I predict someone will be placing a WTS ad soon with an MRO.

The Troy rails' weakness like many early designs was the barrel nut. Compare theirs to a Geiselle and the difference is clear. Hence the Geiselle rail is a lot more solid than the Troy.



There's a lot more to worry about than an exposed FSB being hot. Parallax issues. Rail flex. An M4 clone with a non free floated RAS and Aimpoint Pro is a better option.

The Troy rails' weakness like many early designs was the barrel nut. Compare theirs to a Geiselle and the difference is clear. Hence the Geiselle rail is a lot more solid than the Troy.

Yup. I have an older version of this one. It’s been solid. Little heavier than the BCM rails that I have on other guns, but the barrel nut and lockup is tight…

No sakmak, not what she said…

https://geissele.com/13-5-super-modular-rail-mk14-m-lokr-black.html

heads

Yup. I have an older version of this one. It’s been solid. Little heavier than the BCM rails that I have on other guns, but the barrel nut and lockup is tight…

No sakmak, not what she said…

https://geissele.com/13-5-super-modular-rail-mk14-m-lokr-black.html

probably???

I like 1 MOA at 1000 yards