Fixed vs Folding

[jstyer]

Hey folks,

I've currently been experimenting with some different stuff on my 14.5" gun... And I'm sort of split on sights at the moment.

I've always ran magpul buis due to nice combo of light and cheap. However, in my recent reading I've stumbled across quite a few guys that are really pushing the fixed irons on a 'fighting' gun.

We have some big names here on PF, F2S, Jay, Irish, etc... and I'm curious to hear what you some of you guys think about fixed back ups vs folding.

Any input is always appreciated!

[Failure2Stop]

I prefer a fixed FSB, preferably one that is pinned to the barrel, for a "fighting" carbine.
If that isn't an option due to configuration, I at least want a fixed front sight.
Biggest reason I want a front sight attached to the barrel (aside from the inherant robustness) is that flexing the HG won't affect point of impact.
I have no reason to choose a folding front sight. A fixed FSB doesn't negatively effect my ability to use optics, and is always deployed in case I need to use it in a hasty manner.

Asa far as rear sights are concerned I base it off of the primary sighting device to be used.
With an RDS I prefer a fixed rear.
If I am using a low-powered variable (my preference) or a magnifier, I will go with a decent folding sight.

[rob_s]

As F2S said, the folding rear for the magnifiied optics. What I think he skipped is that typically you have no choice as the magnified optic simply won't allow you to mount a fixed rear sight. The only time I'd choose a flip rear with a non-magnified optic is if it's in an absolute-zero mount (like the non-throwlever Eotechs) or if I was going to use a magnifier with it. In the first case I find the rear sight just blocks too much of the view with the lower mount. In the second case you won't have room for the magnifier with a fixed rear.

On the fronts, I also prefer a fixed front but use, and have used, flip-ups with no real complaints. I keep my role in the forefront of my mind when choosing guns and gear, and when you figure it's a BACKUP iron sight, and where I might be actually using a rifle, having to flip up a front or any shift that might occur are non-issues to me personally. There are applications where I want a small profile at the front of the handguard and not having a fixed FSB in the way, rail-mounted or otherwise, can be useful.

FWIW, a low-profile gas block and just about any rail-mounted front sight will be lighter overall than a fixed FSB.

[orionz06]

I prefer the fixed DD front sight, simple, cheap, clean, and nice. I also have a few sets of folding Troys and they are always in the up position. I find no advantage running them down. If I were to use magnified optics I would be forced to use a folding rear.

I also prefer a rail mounted fixed front sight over a FSB. In my eyes this protects the gas system even more as well as not using the front sight as a heat sink. A trivial difference in my eyes, but one I am drawn towards.

[LOKNLOD]

Fixed Daniel Defense sights front and rear on my SBR w/ an older Aimpoint. They're completely unobtrusive with a lower 1/3 height mount. They're cheaper and I see no drawbacks using them with an RDS. One thing I like about the longer rail with rail mounted sight is that it's a lot harder to burn myself on the sight if it's not attached to the barrel. This is more an issue as the barrel/handguard get shorter. It can also be moved rearward to allow for a 12:00 light mount position without sticking the bezel way out past the muzzle (this does shorten up your sight radius a lot if that is a concern).

On my 16" with a 1-4x, I've got folding Troys front and rear. Low-mag optics are usable with a fixed front, but I don't like it much. And the rear needs to fold for clearance under the rear of the optic. At any rate, in order to use the irons, I would need to remove the optic first. The "flip up the BUISes" step is not the longest item on that timeline (needing to flip them up is not going to prevent me from taking another shot without needing to stop and fiddle with something).

[jstyer]

The DD fixed set was the one I had in mind... coming from someone who has NEVER had a fixed sight gun, do you ever find yourself banging your FS around or having it catch on anything?

[rob_s]

At any rate, in order to use the irons, I would need to remove the optic first. The "flip up the BUISes" step is not the longest item on that timeline (needing to flip them up is not going to prevent me from taking another shot without needing to stop and fiddle with something).

I'm in the construction business. In construction scheduling we talk about the "critical path", which is essentially the longest activity that drives the following activity. To relate it to shooting, if you have a 5 second run from point A to point B and a 2 second reload it makes sense to perform the reload while you're running because "run" is the critical path activity.

I've been looking for other ways to apply this theory and what you describe above is great and another perfect example.

[LOKNLOD]

I'm in the construction business. In construction scheduling we talk about the "critical path", which is essentially the longest activity that drives the following activity. To relate it to shooting, if you have a 5 second run from point A to point B and a 2 second reload it makes sense to perform the reload while you're running because "run" is the critical path activity.

I've been looking for other ways to apply this theory and what you describe above is great and another perfect example.

:D I swear I actually had the words "critical path" in there, but removed it. Flipping sights is still going to be critical path in the magnified optics case, unless you have an extra hand to do it simultaneously with the optic removal, but in the case of the co-witnessed RDS having them up or fixed can remove that step and keep the critical path as short as possible.

[Failure2Stop]

Having a front sight in the "up" position with a failed or fouled optic will allow the user to utilize the sight body and front sight to deliver precise and rapid fire in a compressed environment, even without popping the sight off.
Without that front sight you are forced to rely on point shooting, and while it's an applicable skill, I don't want it to be my sole option.
The time necessary to identify a sight failure and deploy at least the front sight is excessive in the environment and circumstance in which the actions would be necessary.

Folding rear- Rob is correct, I only accept them because the optic won't fit with the fixed or with the folders deployed.

Front sight pinned to barrel vs glued to rail:
A pinned FSB is extremely robust and separating the sighting system from the HG increases consistency and eliminates POI shift from HG pressure.
For most people, it isn't a big deal. I just prefer to retain as much capability with my irons as possible without compromising the primary sighting system. Folding sights have more issues with impact and zero retention. While a hard impact might affect my ability to get hits on a head at 200 meters, it isn't going to make much difference at 15 meters, so how important that aspect is to you is up to you.

I don't look at someone that uses a rail mounted front sight as anything negative, as long as it is "glued" on (as I noted above). Blue loctite at least should be keeping the sight from drifting off. My personal favorite upper has a fixed Troy HK style front sight mounted to the rail.
One can get a sight radius advantage by going with a rail mounted front sight (my old 3-gun had a 13" Troy/Vtac tube, and with a rail mounted FSB the sight radius was longer than an A2). Another issue with a pinned FSB is that you are at the mercy of your gas system length. Even with an FSB cut handguard, you are still limited on where you can put your support hand without getting it burned. HOWEVER- lots of people seem to think that it requires a 15" handguard to do anything other than spray bullets in the general area. While those long handguards can certainly help with extending the reach, they are not a mandatory item, and a lot of reach can be generated by simply extending the stock.
I think that the pinned FSB makes for a simpler, more failure resistant option, and unless I have a defined need for something else, I will prefer to have that feature as a part of my "serious" carbines.

[orionz06]

The Troy TRX-E will flex relative to the barrel. I have not been able to flex it enough while shooting a target to miss (1/4 scale steel) so to me, in any instance I might see it is a non-issue.

[jstyer]

I just cranked pretty good on my handguard (DD MFR) and could not see any visible flex... So that's kinda nice to know.

Sort of off topic, but do you think the advantages of running a light in the 12 O'Clock position are mitigated by the loss of 2.5" of back up sight radius?

[orionz06]

The MFR has a superior mounting method, from a strength standpoint.

[Odin Bravo One]

Fixed, or if it is folded......as is the case on most of my rifles.....the front sight stays deployed for all the reasons mentioned by F2S. Which is why I don't care for the sights that lock in the down position, but won't lock in the up position. Slightest piece of debris can (and will) prevent the sight from fully deploying, thereby drastically shifting your POI.

Time comes my primary optic goes down, the ability to use the optic tube as a hasty rear sight pays for itself. Trying to fumble around and deploy a BUIS in the middle of a TIC is less than ideal for reasons most can easily digest.

For a rear sight, I have one. But I don't use it unless the primary optic is down hard, so if it is up or down is semi-irrelevant. I personally don't like the rear sight deployed, as it clutters the sight picture for no reason. My optic body provides "enough" precision to get off the X until it can be removed and the rear BUIS can be deployed. Co-witnessing does nothing for capability or precision, and is completely useless when hunting at night.

[Tamara]

^^What he said.^^

I am not a 3-gun competition shooter, nor is my carbine part of my action lifestyle, so take this for what it's worth:

I keep my carbine around the house for home defense in various (admittedly extremely unlikely) scenarios. Given the urban location and wooded geography of our neighborhood, the odds of me ever having to, or indeed being physically able to, shoot past a hundred yards, tops, are about the same as my odds of walking on the Moon.

For that reason I use a fixed-front/folding rear setup with the Aimpoint. I suppose if somebody cut down all the trees around our house and bulldozed the neighbor's houses flat, and then my Aimpoint went Tango Uniform, and there were zombies or Red Chinese or whatever farther away than I felt confident using the scope tube for a ghost ring, I could use the folding rear BUIS. Or get the Garand out of the safe, whichever; since I'm already way into a pretty contrived scenario. ;)

[texag]

Slight thread drift, what are yall's opinion on offset irons like the Dueck Defense irons distributed by surefire?

I recently switched to an upper with a low power variable in a non QD mount, so getting to the irons in a hurry ain't happening with a conventional setup. I think these would be much faster to transition to without giving up a bunch to traditional irons.

[joshs]

Here is a thread (http://pistol-forum.com/showthread.php?1684-Thoughts-on-SureFire-Rapid-Transition-Sights) discussing the RTS.

[Surf]

Critical use / duty weapon and it is a pinned / Fixed FSB. The rear is also a fixed unless as mentioned I am running an optic that does not allow for it.

I have been teaching an irons only course for several years and I have seen flex and / or hard impacts on the forend to throw off zero slightly which is mostly noticed at longer ranges outside of CQB. Having said that I do have several "for fun" type of rifles where I run free floats but still run a fixed rail mounted front. SPR type of rifles with magnification and I actually run flip up sight in the down position. Just something I do.

I also run a light in front of the front sight and am not so much worried about the 2" or so in loss of sight radius. Now if I am running an irons only competition rifle without low light stages, then this might alter this placement.

I like to run a lower 1/3 on all of my set ups and I predominantly run EOTech's for a red dot. I have zero issues with using a fixed rear sight with a red dot and don't even notice that it is there.