Detachable carry handle position?

[Blankwaffe]

It's important for ANY device you will attempt to put a zero on, irons, optics, lazerz (be it pointer, designator, illuminator, or ocular interruption)...

...and it's important because, as I stated above, the trend is that it's the single most common step missed, largely because it's not universally described in all the user manuals out there. Whether from spotty review during the tech writing process or a miscomprehension that tension by itself is enough...physics beats both possibilities.

BB, yeah, one generally can't get enough ass behind a coin for it to do what you need. I find that the flat-nosed rasp on the Gerber Multi-tools is a perfect fit in the slots of a carry-handle screw heads

In my experience this very subject is typically not mentioned at all in most instruction manuals supplied with commercial optics mounts....particularly the heavier one piece scope mounts dedicated to large/heavy magnified optics.
In fact I brought this subject up in discussion with one of the mount manufacturers and I could here crickets chirping on the other end of the line.

So yes IMHO I think you and/or F2S would do us all great service if yall did a thread in the FAQ on this important detail.At least I'd appreciate excellent reference material.
Maybe some of the manufacturers will pick up on it and include it into the instruction booklets they print for their mounts.

[arizonaranchman]

My bad...

Sorry bb223 I didn't catch the part that the handle still moves after tightened. Obviously not right. I thought you were just referring to the front not being perfectly flush with the base. That's what I get for being up all nite and trying to answer a post!

[NCPatrolAR]

This info should be put in the FAQ.

Added to the "Knowledge-based" threads thread

[Mung]

In my experience this very subject is typically not mentioned at all in most instruction manuals supplied with commercial optics mounts....particularly the heavier one piece scope mounts dedicated to large/heavy magnified optics.
In fact I brought this subject up in discussion with one of the mount manufacturers and I could here crickets chirping on the other end of the line.

So yes IMHO I think you and/or F2S would do us all great service if yall did a thread in the FAQ on this important detail.At least I'd appreciate excellent reference material.
Maybe some of the manufacturers will pick up on it and include it into the instruction booklets they print for their mounts.

FWIW, we went over this very subject in a recent Colt armorer's school I attended.

[Jimbo45]

You know, when installing sights/optics on rails, I have always held them to the front of the slot when tightening, as suggested in this thread. It makes sense to logically consider that recoil physics would want to move the sight forward, if loose, and it had room to move.

HOWEVER, I have had two carry handle sights work loose enough to move on the rail in the past, while on the range. Not loose enough to move by force or by slamming it with a palm, but loose enough to shift from firing. Guess which way they moved....TO THE REAR, not forward!? Figure that one. I would guess this was a result of the bolt slamming home, when going into battery, being a greater force acting on shifting the sight, than the rearward recoil is. Strange, wouldn't have believed it if I hadn't had this happen twice.

Edit: I retract the above false knowledge. I tried the test below (see my post, three posts down). Must have been an anomaly.

[Failure2Stop]

Guess which way they moved....TO THE REAR, not forward!? Figure that one. I would guess this was a result of the bolt slamming home, when going into battery, being a greater force acting on shifting the sight, than the rearward recoil is. Strange, wouldn't have believed it if I hadn't had this happen twice.

Now, I am holding my rail mounted stuff to the rear of the slot, when tightening.

That's because the lug is bouncing off of the rail. The same thing happens if a rearward placed mount loosens up. That's why we tighten the mount. If this was not true it wouldn't matter if the mount was tight or not. As it is, we know and can prove that a loose mount will result in continually shifting POI. The rearward force from recoil and the buffer hitting the rear of the receiver extension is measurably greater than that of the closing bolt.

It is entirely possible to have success with an optic that is backed into the rail, but it's zero will hold true for a shorter period than one that is mounted with the lug in contact with the forward rail.

You might not believe it, but it has been tested and proven.

You can easily test it out if you have a mount without a center lug, such as a SureFire X200/300 with the plate removed. Just slide it onto a clean and ding-free rail and make a witness mark. Then go to the range and cycle through a few mags. Check the witness marks.

If you try to "do this at home" by simply racking the CH the mount will move rearward, but that's because the only significant impact will be the BCG slamming forward.

At the end of the day, I really don't care how you mount the optic, but if you want to get the most out of it, apply forward pressure while tightening.

[Jimbo45]

Like I said, it loosened enough to allow a shift, but was still tight enough, that I would have had to use a heavy rubber mallet, to try and shift it myself.

But, you have made me curious....I do have a TLR-1 that just so happens to have the lug removed, so I think I will try the test you suggested. Maybe tonight.....

[Jimbo45]

F2S, I stand corrected. You learn something everyday.

I went out to the range tonight, took my optic off my duty carbine, and put the TLR-1 on the flat top upper. I tightened it finger tight, then little a bit more, with a coin. I didn't make it as tight as I normally would, to ensure it would shift.

10 rounds later, it had moved about 1/4" forward. I am not sure what was going on with the M4 carbine with carry handle, from years ago, that moved rearward. I guess it was more loose than I thought, and maybe it was bouncing. Who knows. At any rate, I will go back to placing my stuff at the front of the slot. Thanks for the thread, and for the test idea, F2S!

[Doc Safari]

BB, yeah, one generally can't get enough ass behind a coin for it to do what you need. I find that the flat-nosed rasp on the Gerber Multi-tools is a perfect fit in the slots of a carry-handle screw heads

Good info. I've spent all day looking for a screwdriver with a wide enough blade to fit the thumb nut slot. I swap out the carry handle and the ACOG on one rifle frequently because I often shoot irons and optics on the same day and don't want to carry more than one rifle to the range.

[Iraqgunz]

This necropost definitely moves up your ranking.

Good info. I've spent all day looking for a screwdriver with a wide enough blade to fit the thumb nut slot. I swap out the carry handle and the ACOG on one rifle frequently because I often shoot irons and optics on the same day and don't want to carry more than one rifle to the range.