Tools/gauges for Aligning Hand guard and upper perfect? I’m

[URGILOVERR]

I have a Geissle mk16 rail and have been wondering how I could align it as perfect as possible to my upper I stumbled across some YHM dovetail vise jaws does anybody have any experience with these? Any other tools or gauges out there for precision alignment? I bought a cheap riser that can clamp to the reciver and handguard but I’m not sure about it’s precision.

 

[TheOE800]

JP vise blocks

 

[Zak Smith]

I just use an old thumbscrew ACOG mount to bridge the two while tightening the screws

 

[shoobe01]

Usually just do normal machine tool processes. Use straight edges on the corresponding surfaces and so on. But if the rails aren't lining up perfectly, agree with Zak that just getting it close then clamping on a reasonably quality spare railgrabber to bridge the two (and inspect that it is on right, not canted etc when done torquing) then tighten up the handguard attachment screws.

 

[Zak Smith]

The nice thing about the Geiselle rails is that they don’t start crazy tight and aligning them is easy.

 

[stevieb92]

I have this tool from Brownells. It works pretty decent, but sometimes it is rather snug on some rails depending on whether or not the raile has been cerakoted.

https://www.brownells.com/tools-cleaning/gun-tools/rifle-tools/ar-15m16-handguard-alignment-tool/

 

[gopherslayer]

I use a cheap Weaver riser mount with big knobs on it that I picked up on clearance.

 

[Yondering]

As others have said, use some sort of rail-mount section (scope mount, riser, etc) that spans the joint and can clamp on both pieces. Clamp that on, then tighten the handguard - done. And that's not "second best" to spending a lot of time measuring everything, or buying a specialized tool of some sort - it's the better and more efficient method.

Sometimes the simplest methods are the best.

 

[NetChemica]

Search for "NO-M.A.R Pic Rail Soft Jaw Vise Clamp".

The issue with using an optic mount or the Brownells tool that was listed is that they only clamp from one side. It's fine if the pic rail on your hand guard is exactly the same width as the one on your upper, but most are not. The NO-MAR option will apply equal pressure from both sides and will align your handguard even if the pic rail does not have the same thickness. The standard is (I believe) 0.830-0.835", but you'd be surprised how many brands do not meet this spec.