Iron Sight question, again

[wa2bop]

Greetings,
New FNAR owner here. I know the subject has been discussed, and have read the archives.
I have a heavy barrel version. I know it is a tapered barrel, and is .75 inches at the end.
Have not seen anyone try a clamp on gasblock/front sight, especially a 'two clamp' configuration. Has anyone tried? Shims?
Thanks,
Barry

[pattonme]

How about something like this? I haven't made it on my mill yet, just finished the CAD

more pics at https://picasaweb.google.com/pattonme/FNARFrontRail
fnar sight-1.jpg

[SgtStrykerUSMC43]

Greetings,
New FNAR owner here. I know the subject has been discussed, and have read the archives.
I have a heavy barrel version. I know it is a tapered barrel, and is .75 inches at the end.
Have not seen anyone try a clamp on gasblock/front sight, especially a 'two clamp' configuration. Has anyone tried? Shims?
Thanks,
Barry

The issue is the barrel is tapered and would have to be turned in order for the .750 gas block idea to work.

-SS

[pattonme]

The issue is the barrel is tapered and would have to be turned in order for the .750 gas block idea to work.

-SS

actually no. all you need is a tapered insert. anyone with a lathe can make it. just bolting something like the AK gas blocks to the barrel is the easiest thing. But the rail height is WAY, WAY too high. Though if anyone wants to try the Armalite AR-10 gas block (EU0238KIT) probably has the lowest deck height. The next likely candidate is the Precision Reflex 03-875-04 (Precision Reflex - Product Detail - Armalite .875 Picatinny Railed Gas Block - $65.00). If anyone wants to try them, I'll make the tapered inserts.

[scudzuki]

Tapered?
I just measured mine.
The barrel is straight for several inches back from the muzzle.
Split clamp block with a tapped hole on top to fit a KNS adjustable post for an AR.

First the bore centerline from the top of the rail must be measured... my surface plate is not big enough but I could do it on the table of a mill.
Then pick a rear sight, from that calculate the height of the front post.

A bit of work but if there was enough interest I might bang out a few (keeping one for myself of course).
Mine would likely never get used though. I see a 12x or more magninication scope perched on my FNAR for the forseeable future.

Joe

[pattonme]

I have the heavy fluted barrel and it's tapered almost all the way. If you want to put the front sight all the way to the front the rail height is probably 13-15mm (from barrel top). I'll have to measure. BTW, a granite kitchen counter works as a surface plate. It's not like we need accuracy to the hundredths or better.

[scudzuki]

I'v been trying to determine whether the rifle I bought brand new for $1079 (with 2 mags) is an HBAR.
It's been suggested on this forum that it must be the HBAR if I got it for that price since that's the one they're blowing out.

My barrel is .768" from the handguard to the muzzle. No taper at all, as best I can measure with a set of Sylvac-Fowler digital calipers (one of the first on the market back in the 80s when I was a production machinist).

The granite is a good tip... although my wife gets pissed when I work on the guns in the kitchen.

Fortunately I have a VMC (CNC milling machine) with a 40" table. It's flat.

Joe

[pattonme]

I got mine for $999 too from CDNN. The taper is so obvious it is readily seen just by looking at it. goes from ~1.125" at the nut to 3/4" at the tip. Maybe the first inch from the end isn't tapered but in all likelihood it is. Just can't eyeball it. By 2 inches back the dimeter is bigger by 1/32".

[scudzuki]

I first learned of the FNAR from the CDNN sales flyer.
By the time I ship it here, pay an FFL to transfer it, and buy the 2nd mag, I'm over $1100, so I made out okay.

Yeah, I guess after 20 years in the machine shop (1st class machinist, CNC programmer, toolmaker, machine designer, shop foreman) it is possible that I can't accurately measure the O.D. of a rifle barrel.

I suggest you measure yours before you go shooting your mouth off anymore about how obvious it is to the unaided eye.

Joe

[pattonme]

clearly we don't have the same rifles. Nobody accused you of not being to wield a ruler, so keep the chest thumping in check. I'm no FNAR expert but it sure sounds like you do NOT have a heavy barrel or there were 2 versions; tapered and untapered. Lest you continue to think I'm "shooting my mouth off" it's 19.5mm at tip. 19.86mm 1" back. 20.34mm at 2" back. 22.5mm 6" back. etc. etc. 30.65mm at nut. So there, the taper is bloody obvious even to the naked eye and my Chinese digital calipers work fine. My eyeballing figure was RIGHT ON the money to boot and I'm just a self-taught hobby machinist with 2 years of playing in my garage.

There was no need to make yourself look silly by insulting me.