Front BUIS location on rail

[CGA]

So you have a 16" barrel with a 15" rail and an Aimpoint. Where do you place your front flip up sight? As far out on the rail as you can to increase sight radius, or closer to your hand for rapid deployment? Is there a general rule of thumb?

[orionz06]

Generally speaking you can get more precision with the FS further out. Other attachments such as lights may influence the position, along with where you hold the gun while shooting. Many folks also leave the front up so deployment isn't really a consideration.

[CGA]

Let's say nothing else is in the way on the rail.

[Jay Cunningham]

It depends.

I've never considered close to my hand for rapid deployment as a criteria.

Primarily it depends to me on how the WML is mounted, and if you have rail-mounted controls for stuff. My current carbine has the front sight placed about 5 or 6 rail spaces back from all the way forward on an 11" rail, however I tend to leave the front sight deployed.

[Lon]

Depends. Where is your light going? I know guys that run their light at 12 o'clock at the end of the rail with the FS right behind it. If your not going to do that, I'd run my FS all the way out at the end.

[orionz06]

Let's say nothing else is in the way on the rail.

I would put it on the very end then. Technically it offers greater precision. Though it may not translate to more accurate shooting I see no reason to place it further rearward.

[CGA]

For the light, I have a Gear Sector offset mount that will take up very little top rail space. I don't have particularly long arms, so mounting that close to my hand will still leave me ample rail space for the sight.

[SamuelBLong]

I would put it on the very end then. Technically it offers greater precision. Though it may not translate to more accurate shooting I see no reason to place it further rearward.

Kyle Defoor did some testing regarding accuracy & speed vs sight radius with irons a while back. I seem to recall that he said the optimal placement for speed and accuracy was just short of a standard 14.5 carbine fixed front sight radius.

[orionz06]

I am 5'6" and on my 15" rail guns I have the VTAC mounts with G2's or similar lights, offset to the right with the front sight at the very end. Plenty of room for activation.

[CGA]

Kyle Defoor did some testing regarding accuracy & speed vs sight radius with irons a while back. I seem to recall that he said the optimal placement for speed and accuracy was just short of a standard 14.5 carbine fixed front sight radius.

That's one reason I was asking. Though I didn't know why, I've seen pictures of 16" carbines set up by him, and others, with front flip-ups far rearward on the rail without obstruction by any other accoutrement.

[orionz06]

That's one reason I was asking. Though I didn't know why, I've seen pictures of 16" carbines set up by him, and others, with front flip-ups far rearward on the rail without obstruction by any other accoutrement.

The further out on the rail the slower it is to aim. The closer to the rear sight the faster it is to aim. Your index on the rifle will influence this a bit too. Think of it as a fine and coarse slider on a scale. Once out so far it begins to seem like you are wiggling the small weight around. This is an exaggeration of course but still the same principle. If you wanted to truly test it out I would start with some groups on paper with the sight at each end of the rail and see what the difference is. The ammo and mechanical accuracy of the gun will come into play too.

[rob_s]

I have spent a LOT of time/rounds with an irons-sights disspator configuration, so I like, and am familiar with, that sight radius quite a bit, almost always with the small aperture.

On a 16" barrel with 15" handguard, I would personally also be thinking about limiting what I can jam the muzzle into in terms of things like a 9-hole wall. I like to generally hold my front sight back the length of a Surefire X300 plus one slot for that reason, and I can remove the Surefire as-needed for tight holes.

[philpac33]

My main rifle has a 16" bbl with 15" rail. After much swapping of accessories I've settled for an Inforce/HSP WML at 12:00 as far forward as possible and the BUIS directly behind it. The angled activation of the WML makes having them so close together non-problematic.