Calguns.net  

Home My iTrader Join the NRA Donate to CGSSA Sponsors CGN Google Search
CA Semiauto Ban(AW)ID Flowchart CA Handgun Ban ID Flowchart CA Shotgun Ban ID Flowchart
Go Back   Calguns.net > FIREARMS DISCUSSIONS > Optics, Mounts, Rails and Sights
Register FAQ Members List Calendar Mark Forums Read

Optics, Mounts, Rails and Sights If it aims your firearm, post about it here.

Reply
 
Thread Tools Display Modes
  #1  
Old 11-21-2007, 7:19 PM
fourZero's Avatar
fourZero fourZero is offline
Member
 
Join Date: Aug 2007
Location: Bakersfield, CA
Posts: 129
iTrader: 2 / 100%
Default Glass options for 2HT flat top upper

New to the forum, I have been lurking for a bit but have not said much. I have a featureless build with a CMMG lower, RRA NM stage II LPK, A2 stock, MM grip, Stag 2HT upper, and some bolt-on goodies.

Here are pics of my original setup, using the ARMS 40L (comes with the 2HT upper) and a Bushnell Trophy 1x32 Holosight:




After using the Bushnell, I was satisfied with the co-witness on the front iron sight (not a big fan of co-witnessing with the rear, but a fantastic backup if batteries run out). After shooting a few hundred rounds at about 110 yards, I was really aching for some magnification. I sent the Bushnell back to Cabela's for a Nikon Buckmaster 3-9x40 (comparable in price), and I am now kicking around some mounting options.

The rifle is now configured as such, I got an ARMS #32 and Harris ultralight swivel bipod, CAA light mount with G2 Nitrolon, and some rail covers. Also note the DPMS Levang linear compensator, seems to work well but I have no reference point to compare to:



I'm looking at 3 options here, and leaning towards the Armalite 1-piece mount.

I bastardized pictures from several posts, please forgive me.

Option 1:
Armalite 1-piece with integrated rings:

You can see clearly that the eyepiece does not clear the standard ARMS BUIS, but I *think* the 40L is low enough to work with this setup. It is impossible to gauge for certain from this photo, however. This setup runs just under $90 direct from Armalite. Can anyone confirm clearance?

Option 2:
ARMS 22 throw-lever rings:
ARMS claims 1/8 MOA +/- accuracy with this setup, can anyone confirm? Also, would I want the low, medium, or high rings on a flattop setup? Remember, I have a continuous rail from the charging handle to the front sight, so eye relief would not be an issue with this setup. Looks like around $120 for a pair, general consensus is to go with the high rings.

Option 3:
LaRue LT-104/LT-158
Obviously the best quality. Plug & play with my setup, proven to clear the 40L rear BUIS. Downside: cost. $195.


Before you go and say "LaRue FTW," please keep in mind that my wife just gave birth on Monday, and she will not be returning to work. We are by no means in the poor house, but if I can get an acceptable setup with the Armalite at half the cost, I will certainly do so. If the ARMS 22 really do hold zero, that may be the most flexible option of all, since I have almost limitless options on the top of the upper to play around.

Thoughts, suggestions?
__________________
Political correctness is a doctrine fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

Last edited by fourZero; 11-21-2007 at 7:39 PM..
Reply With Quote
  #2  
Old 11-22-2007, 8:37 AM
Mute Mute is offline
Calguns Addict
 
Join Date: Oct 2005
Location: Diamond Bar
Posts: 5,551
iTrader: 22 / 100%
Default

If you really want to make sure the setup holds zero, I suggest saving a few bucks and going with Larue. Just personal experience.
Reply With Quote
  #3  
Old 11-22-2007, 11:23 AM
maxicon's Avatar
maxicon maxicon is offline
Veteran Member
 
Join Date: Oct 2005
Location: San Jose
Posts: 4,598
iTrader: 23 / 100%
Default

Hey, I recognize that Fab 10!

AR optic mounting is a real mish-mash of conflicting measurements. That's why you can buy so much cheap stuff on the arfcom EE - people buy things that don't work as they hoped.

Yes, the full-length rail will avoid the eye relief problems, so high rings will likely work (depending on how high they are - everyone's highs tend to be different heights, and most spec to the bottom of the tube, while some spec to the centerline).

I haven't used ARMS rings, but some of their other mounts have a reputation at arfcom for loosening up over time. The LaRue will avoid that, according to users.

As for what BUIS will fit under the scope ocular, it depends on mount height, scope ocular diameter, and BUIS height. The LaRue gives a bit more height than the Armalite and gives more flexibility, but without knowing the scope ocular diameter, it's hard to say.

The Troy BUIS is one of the lowest, but is also more expensive, especially since you've already got a 40L. These numbers were recently posted over at arfcom for BUIS heights:
ARMS 40L - 0.610 above rail
Troy - 0.46 folded

Here's the centerline height of various LaRue 30mm mounts - subtract 0.09" for 1" mounts:

From LaRue - Our 30mm SPR mounts vary in height by model, and the heights of the centerline of the optic above the top of the rail are as follows:
LT104-1.5
LT135-1.93
LT139-1.5
LT158-1.44

I measured the centerline on my Armalite 1" one-piece at 1.25" some time back. That seems low, and I'll re-check this weekend.

So, what you'd need to do is measure your rear ocular bell diameter, divide it by 2, and subtract that from the centerline of the mount or rings. That would give you the clearance above the rail for the BUIS to fit.

For instance, the Burris XTR 30mm high rings are 0.75" to the bottom of the scope tube. Add 0.59" for half the diameter of a 30mm scope tube, and your centerline will be at 1.34". If your eyepiece is 1.5" in diameter, you'd subtract half of that, or 0.75", from the centerline, giving 0.59", which is what height BUIS would just touch the bell.

In this example, the ARMS 40L wouldn't fit (but would with XTR extra high rings at 1"), but the Troy would.

I'm a value-oriented guy, but if money were tight and I wanted to use my existing 40L, I'd seriously consider the LaRue just to avoid having to try different sights.

Another option would be the Model 1 Sales one-piece, which doesn't have much eye relief (not a problem on your setup) and reportedly offers more height than the Armalite, but I don't know the exact height. It's cheaper than the Armalite and is semi-quick release, like the Armalite. You won't get the same RTZ as the LaRue.

Good luck, and keep us posted on your results!
Reply With Quote
  #4  
Old 11-22-2007, 11:46 AM
Socal858's Avatar
Socal858 Socal858 is offline
Senior Member
 
Join Date: Jul 2006
Location: San Diego
Posts: 2,018
iTrader: 41 / 100%
Default

the armalite setup is pretty expensive and extremely low. you can buy the rock river one piece mount from wes at 10% or adco firearms. something like 40-50 bucks. i do not know if they make one for a 30mm tube, the one i had previously was for a 1 inch tube.

another option are buying the burris extreme tactical rings from david at riflegear.

these methods are good equipment but NOT quick detacheable and not guaranteed to keep zero
Reply With Quote
  #5  
Old 11-22-2007, 3:57 PM
fourZero's Avatar
fourZero fourZero is offline
Member
 
Join Date: Aug 2007
Location: Bakersfield, CA
Posts: 129
iTrader: 2 / 100%
Default Thanks

Quote:
Originally Posted by maxicon View Post
Hey, I recognize that Fab 10!

Good luck, and keep us posted on your results!

Lots of good info there, thanks a bunch. I will keep everyone posted, and most likely just sucker the old lady into the LaRue just like I suckered her into this build in the first place ("but sweetie, what happens if we have a natural disaster like an earthquake and it gets wild like it did after Katrina?").
__________________
Political correctness is a doctrine fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT -8. The time now is 2:00 AM.




Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Proudly hosted by GeoVario the Premier 2A host.
Calguns.net, the 'Calguns' name and all associated variants and logos are ® Trademark and © Copyright 2002-2016, Calguns.net an Incorporated Company All Rights Reserved.