Recommend a Picatinny "Bridge"

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[ARCHIVED THREAD] - Recommend a Picatinny "Bridge"

Posted: 9/15/2019 5:27:01 PM EDT

I just built an upper with a free-float handguard that exhibits a little bit of downward flex such that it can pull away slightly from the front face of the upper receiver producing a small and annoying gap:

Can anyone recommend something that attaches to the Picatinny rails on the handguard and upper to bridge the gap and prevent the handguard from pulling away? I won't be mounting an optic in this area. A short, low riser maybe 2" or so long could be enough, but the smaller and more unobtrusive the better.

Posted: 9/15/2019 10:47:57 PM EDT

[#1]

I will say, the receiver and handguard rail height don’t look even to start out with and even if they were, if that gap actually opens and closes when pressure is applied to the handguard, there’s something wrong with either the install or the handguard itself, neither of which will be correctly fixed by a picatinny “bridge.”

If everything is good with the install, contact the manufacturer and ask for a replacement or refund, because a properly installed handguard should not shift on a barrel nut.

ETA: Out of curiosity, who makes the handguard? Got a pic of the full thing?

Posted: 9/15/2019 11:23:01 PM EDT

[#2]

What forearm is that? Looks terrible

Posted: 9/16/2019 9:02:40 AM EDT

[#3]

Quoted:
I just built an upper with a free-float handguard that exhibits a little bit of downward flex such that it can pull away slightly from the front face of the upper receiver...

View Quote

That's not normal, and sounds completely unacceptable. Is it made out of plastic or something? Is this an airsoft gun? The rail sections don't appear to align in height and the grooves don't look like they align either. Instead of paying $30 for a band aid, throw that thing in the trash and buy a new rail, a good one can be found for not much over $100

Posted: 9/16/2019 11:37:00 AM EDT

[#4]

I'm not going to trash the manufacturer. In normal handling this handguard looks and feels fine, and the gap is not there - I doubt anyone would notice in normal use. I found the issue when I tried to flex the (lightweight) barrel upward by leveraging against the handguard to check clearance above the gas block... only then did the handguard move slightly.

It sounds like nobody has a good solution other than "replace the handguard". This is an inexpensive beater gun that I'm not going to put a lot of $$$ into. I have found an inexpensive riser that I think will do the job. If it works out, I will post a pic here for posterity. Thanks everyone for your input.

Posted: 9/16/2019 11:40:53 AM EDT

[#5]

Quote History

Quoted:
I'm not going to trash the manufacturer. In normal handling this handguard looks and feels fine, and the gap is not there - I doubt anyone would notice in normal use. I found the issue when I tried to flex the (lightweight) barrel upward by leveraging against the handguard to check clearance above the gas block... only then did the handguard move slightly.

It sounds like nobody has a good solution other than "replace the handguard". This is an inexpensive beater gun that I'm not going to put a lot of $$$ into. I have found an inexpensive riser that I think will do the job. If it works out, I will post a pic here for posterity. Thanks everyone for your input.

View Quote

I love when people come here for advice and then disregard everything they’ve been told, instead opting to jury rig a solution that probably won’t work. Especially when there are budget options out there that get good reviews.

You do you, just know, that should NOT be happening with any handguard and what you’re attempting to do to fix it is nothing but a poorly placed band-aid. Why on earth you wouldn’t attempt contacting the manufacturer to get a replacement is beyond me. Anyways, good luck, but I highly doubt anything you attach to that handguard is going to maintain anything resembling a zero.

Posted: 9/16/2019 12:12:52 PM EDT

[#6]

It's a cheap shitty handguard that is performing exactly at its price point. If you don't mind cheap/shitty, then that's what the free market is for. But "bridging the gap" isn't going to make the platform any more solid, since if it flexes that easily, it will flex in any direction and the "bridge" you're talking about only covers the top. In addition to look ridiculous and getting in the way, it won't actually make your rail a more solid platform for mounting any kind of sighting system, including a front iron sight.

If you're not planning on mounting a laser or front sight on the rail, then the flex you're experiencing doesn't actually functionally impact the use of the rifle. It's just flimsy, but as long as it isn't contacting the barrel or gas block at its extreme flex, you shouldn't notice any actual problems.

Posted: 9/16/2019 12:14:02 PM EDT

[#7]

Quote History

Quoted:
I love when people come here for advice and then disregard everything they’ve been told, instead opting to jury rig a solution that probably won’t work...

View Quote

There is no need to be rude or condescending. I was not really optimistic that what I asked for existed, but I came here to be sure I hadn't missed anything. I appreciate the time folks took to reply. For my particular application, a BandAid is quite acceptable - I'm not mounting anything on the handguard and I already have plenty of high-quality ARs for serious applications.

Posted: 9/16/2019 12:29:17 PM EDT

[#8]

FYI, its a LUTH-AR Palm handguard.

Posted: 9/16/2019 1:45:36 PM EDT

[#9]

So a small gap is more annoying that bolting a superfluous riser on to bridge the gap? If that's not correct explain it to me as I'm not really understanding.

Posted: 9/16/2019 2:42:19 PM EDT

[#10]

Quote History

Quoted:
So a small gap is more annoying that bolting a superfluous riser on to bridge the gap? If that's not correct explain it to me as I'm not really understanding.

View Quote

Indeed. That just shouldn't happen and I would be looking for a replacement for the handguard, not a "patch"

Posted: 9/16/2019 7:09:25 PM EDT

[#11]

Don’t mount irons to it. They will experience zero shift as the forearm flexes

Posted: 9/16/2019 7:11:09 PM EDT

[#12]

Quote History

Quoted:
So a small gap is more annoying that bolting a superfluous riser on to bridge the gap? If that's not correct explain it to me as I'm not really understanding.

View Quote

Correct - a small gap is more annoying that bolting a superfluous riser on to bridge the gap. That's why I asked the question.

Posted: 9/16/2019 7:15:14 PM EDT

[#13]

Quote History

Quoted:
Don’t mount irons to it. They will experience zero shift as the forearm flexes

View Quote

Indeed, I'm not planning to. This is a cheap upper I am putting together to use up a worn out barrel and a bin full of prize-table freebie parts. I am going to drop an old Ciener .22 kit into it and use it for plinking mostly. Nothing will be attached to the handguard. I found a cheap riser on Amazon for $9 that I think will do the job. I don't care what it looks like as long as it functions.

Posted: 9/16/2019 11:37:48 PM EDT

[#14]

Huh - all the LuthAR stuff I’ve used has been very good quality. Maybe give ‘em a call? I saw the handguards being clearanced-out a few months back - maybe something was up. The design is a bit divisive but I wouldn’t think they’d be turds.

Posted: 9/17/2019 3:14:13 PM EDT

[#15]

I had the same thing happen to me when mixing handguards and uppers.
I purchased cheap “45degree offset picatinny scope”
attachments off eBay ($3 each), and connected two of them together (bridging the gap) with a 4mm steel rod on the sides. It takes some minor fabrication but it’s very solid.
They sell a unit already made, but it’s like $30-40 and what’s the fun in that?

[ARCHIVED THREAD] - Recommend a Picatinny "Bridge"

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