BOHICA and Armalite scope mount? why does it not work..

[tlillard23]

I bought one of the armalite 1 piece 1" scope mounts/rings for my BOHICA.

http://www.armalite.com/ItemForm.aspx?item=EX0027&Category=a14c8168-f1cf-4f11-8859-bafe17a66e1e

http://www.bohicaarms.com/far_50.html

The armalite mount has a lug and 2 shafts that engage the groves in the bohica/picatinny rail. about every 3rd set of groves doesn't fit the mount. one of the shafts on the mount doesn't always line up with the groves in the Bohica rail.This causes the mount to not sit flat on the rail. what gives, or maybe operator error?

this is MY third F-up on the bohica(not BOHICA's fault). I am about ready to sell the mutha, I seem to be bringing bad luck to this gun.

[Nefarious]

Well... you know 2 things.. its either the rail or the mount
I understand your frustration...ive wanted to get rid of my upper a couple times now.

Have you tried using the mount on, say, a flat top AR to see if you still get the fit issues. I know when I have my scope mounted to the Bohica (using the Nightforce unimount) I have my windage set ALL THE WAY OUT.. which bothers me, but the mount does sit flat. Its definitely possible there are QC issues with the rail

I dont know if you saw MustangO3's and My recent comment out our last trip out.. but we started with 2-3" groups @ 100 yards, and ended up the day with 1-2" groups. That said, I still look at this upper like a "bargain" type upper.

[maxicon]

Sounds like the Bohica's rail isn't Picatinny spec. I've seen the same thing with my SU16A (the B and CA are Picatinny spec) and a cheap Chinese rail segment I bought, but the Armalite rail fits all the good AR gear I've got.

If you've got a caliper or machinist's ruler, check out the slot spacing and Armalite screw spacing against this drawing:

http://www.biggerhammer.net/picatinny/

The groove width should be 0.206 +.008/-0" and the spacing between slot center and slot center (or face to face, which is easier to measure) should be 0.394".

You can't change the Armalite screw spacing easily, but you could do one of the following:

- Open up one of the Bohica's slots so it fits (which will affect resale value, of course).

- Find a rail riser that will fit the Bohica and mount the Armalite on that. This may be hard to find, due to the same problem, and will increase the height of the mount. The Armalite can use an extra 0.2" on some guns, but many risers are 0.5" or more.

- There are a few mounts with a single cross-slot screw, like the KAC Dual Ring 30mm Scope/Reflex Mount #32968 (can be hard to find) or the CAA Dual Scope Ring Rail Mount (cheap, and may not hold well on a Bohica).

http://www.knightarmco.com/mod_weapons_2.htm

http://www.aimsurplus.com/acatalog/Command_Arms_Dual_Scope_Ring_Rail_Mount.html

I don't know why anybody makes stuff that's not Picatinny spec, but they do.

[tlillard23]

Hmmm, I see now.... THIS BLOWS GOATS

[Nefarious]

If it does turn out to be the rails, they are under warranty. Call up Chris and let me know whats going on.

Pain in the rear I know.. more headache... more frustration ... more wait time ... you can always get "Nefarious-crazy" with it

[ar15barrels]

Beware the differences between Weaver and Picatinny rails.
I thought that the Armalite mount was available either way so perhaps the wrong one is being used?

[maxicon]

There are 2 general differences between Picatinny rails (which follow a spec) and Weaver rails (which are a design concept).

- Slot width, depth, and shape

- Slot spacing

It's the slot spacing that causes the most trouble in a case like this, as a large percentage of gear will fit in either a Weaver or Picatinny slot (though the recoil lug on the Armalite mount may be too wide for some Weaver slots).

The Armalite's only available in one rail version (with either 30mm or 1" rings), spaced for the Picatinny spec.

[tlillard23]

Just for anyone looking. the original BOHICA's were NOT true Picatinny spec. later configurations have been corrected.

[ke6guj]

Just for anyone looking. the original BOHICA's were NOT true Picatinny spec. later configurations have been corrected.

+1. IIRC, the MK1's are not Picatinny, but the MK2 and MK3s are true Picatinny.