Cat Tail clearance on extended mounts...

[Rmplstlskn]

Just when I thought I found the perfect mount for my Meopta Meostar R1 to go on my FAL, and just before I purchased one (Bobro Extended 30mm), I bumped into a Bobro thread here about cat tail lever clearance issues with extended cantilever scope mounts....

ARRRGGHHH....

Anyone have the exact (or almost exact) measurment from the top of the mount base to the bottom of the 30mm scope opening? For both a Bobro or American Defense?

Neither manufacturer web site has THAT specific measurment...

For my Meopta with Larue Cat Tail, I need 14mm (0.55") at minimum.

Trying to avoid also replacing a working and mounted Larue lever (more $$$ spent)... Will go with the 3gunstuff.com scope lever if needed, but damn, when does the spending end on upgrades? LOL!

Also, the reason I believe the extended mounts best for my use on an FAL is this puts the actual clamp part over the most sturdy part of the ARMS scope cover (behind the ejection port).

Thanks in advance to anyone with first-hand experience sharing their solution or to anyone posting these measurements.

Rmpl

[ICANHITHIMMAN]

I had an issue with my BOBRO mount and a USO SN4. I spoke with Andrew Bobro and he send me a replacement arm at no cost. Got my scope down low and I could still operate my ring. I have the old arm if you want to try it out. I think its the extended version.

[Rmplstlskn]

I have the old arm if you want to try it out. I think its the extended version.

Learned another thing... Didn't know the arms could be swapped on the Bobro, thought it was all one solid piece like the Larue.

Not sure if the arm will help me without the rings, unless the bottom ring is part of the arm... If so, that would help a lot!!!! PM me if it is and I'll PayPal you some dough for shipping...

This is the best site on the net!

Rmpl

[Failure2Stop]

I'll try to get you a measurement on my Bobro and Larue SPR in a minute, I'm moving so stuff is a bit jumbled up right now.

ETA- this is a really hard measurement to get with an optic in the rings and my calipers buried somewhere dark.
ETA2- yeah, without my caliper I can't give you a measurement with any degree of validity. It's like timing a USPSA stage with a sun-dial.

[El Cid]

I can't get you measurements on the ADM until this evening. Is this the ADM mount you are asking about? The cat tail on my Swarovski clears it just fine. What diameter are you looking at with your scope/tail?

http://i828.photobucket.com/albums/zz209/El_CidAF_ResQ/MCSPRwGlass5.jpg

[Rmplstlskn]

Here is what I am dealing with...

El Cid, your lever seems thinner than the Larue... It is looking like I will have to ditch the Larue if I want to use the scope mounts best suited for my FAL...

http://i247.photobucket.com/albums/gg141/jasontielke/Sale/IMG_3222.jpg

http://i247.photobucket.com/albums/gg141/jasontielke/Sale/IMG_3224.jpg

The FAL it is going on...
http://www.wwyd.org/images/AR15/FAL-left (Medium).JPG

Rmpl

[shootist~]

Is this a different Bobro mount than for an AR? Seems like it would put the optic too high for a FAL. I'm able to use standard rings on FAL mounts - with eye relief set for head position well forward.

ETA:

..measurment from the top of the mount base to the bottom of the 30mm scope opening? For both a Bobro
It's about .32" on my extended Bobro.

[shootist~]

It's ~.32" per my edit above.

[Rmplstlskn]

Here is my thoughts on the ARMS mount and standard rings... See pic. The ARMS mount is only slid into the grooves of the receiver like the original sheetmetal cover. It does not BOLT on like the DSA Extreme Mount. Because of this, the ARMS mount can "flex" a lot more in that section that rests above the ejection port as the ARMS mount is only secured on ONE SIDE. So the use of regular scope mounts would put the mounting points into the forward half of the mount, into an area I think is its most flex-inducing point during recoil. So my concern is zero return with a heavy scope up on top there...
http://www.wwyd.org/images/AR15/FAL-r-rcvr-ARMS-issue.jpg

The extended cantilever mounts put the mounting base well within the REAR half of the mount where BOTH SIDES are securely held, no twisting or flex. The best location for a heavy scope on a rifle that was never designed for such accoutrement...

I used to have the DSA mount, but I didn't like the WEIGHT of it, nor the aesthetics that clashed with the sleek lines that make the FAL such a looker... The ARMS mount keeps much more to the sleek, thinness of the FAL lines as well as is easily slid off, unlike the DSA mount with its battery of screws and lock bars... But the DSA mount would have zero problem with a scope in the front half, IMO... The ARMS mount, not so much, from my pulling and pushing on that area...

Rmpl

[El Cid]

I came up with 21/32 (.656) inches. Not exactly scientific - lol! Had to cut a business card to fit then measure it.

http://i828.photobucket.com/albums/zz209/El_CidAF_ResQ/photo-14.jpg

http://i828.photobucket.com/albums/zz209/El_CidAF_ResQ/photo-15.jpg

[Rmplstlskn]

Hey, the ADM mount looks like it is GTG with the Larue lever... Thanks a lot El Cid! I need 0.565" and you have it measured at 0.656"

BTW, that is sweet glass on a fine firearm El Cid!

Now for future thread-searchers, if we can get a Bobro measurement... I suspect it is shorter due to the arm design.... Any luck finding the Bobro and a measuring device Failure2Stop?

[El Cid]

Hey, the ADM mount looks like it is GTG with the Larue lever... Thanks a lot El Cid! I need 0.565" and you have it measured at 0.656"

BTW, that is sweet glass on a fine firearm El Cid!

Thanks! Happy to help. Just remember that is an approximation. I can't guarantee I cut the card perfectly straight and parallel to the bottom edge. Though it would seem you enough room to make it work.

[Failure2Stop]

Any luck finding the Bobro and a measuring device Failure2Stop?

Sorry, calipers are in my storage unit.
Might be able to get ahold of it tomorrow.

[Boxerglocker]

OP, I feel your pain... I had my Vortex Viper 1-4 PST on a extended Bobro. Worked great until I decided that I needed and wanted the switch-view lever. Only way it would fit was to bring it back in the mount as far forward as possible.
I went with the Larue 104 and am happy... to be honest I like the clean look of the Bobro rings but find them a PITA to torque. I found that I don't miss the extended eye relief much if at all for the particular rifle I have it mounted on a Rainier RUC.

[Rmplstlskn]

Is this a different Bobro mount than for an AR? Seems like it would put the optic too high for a FAL. I'm able to use standard rings on FAL mounts - with eye relief set for head position well forward.

With shootist~'s comment in mind, several FALFiles threads later, as well as hours fiddling with the scope and the FAL together, adjusting heights and experimenting with cheekwelds the FAL offers, I have come to the conclusion that SCOPE RINGS that bring down the scope as LOW AS POSSIBLE is the best solution...

The AR-height that Bobro, Larue & ADM maintain is workable, but on an FAL, it definetly forces you to have a poor cheek weld and a more upright head position. Basically sloppy and hard to repeat every time exactly.

I also am hoping that since the FRONT of the scope is the lightest part, that having that scope ring over the less-secure part of the mount (only one side secured), the .308 recoil won't affect it. The rear scope ring is solidly within the strongest part of the mount, and that is where most of the weight is...

So rather than turn this thread into an FAL gunsmithing thread (I will make another post in the "Other Assault Rifles" section for that), here are a few pics of the end result...

Thanks everyone for the help here, and I know exactly what I need to do if I move this scope over to my AR platform...

I used LOW Warne Maxima QD rings, which forced me to do some ARMS mount modifications. I also had to abandon the Larue cat tail lever :( But this is the LOWEST possible mounting of this scope in an FAL... It now has a VERY NICE check weld, almost like usin the irons!

http://www.wwyd.org/images/AR15/FAL_ARMS-mod (3) (Medium).JPG

http://www.wwyd.org/images/AR15/FAL_ARMS-mod (6) (Medium).JPG

http://www.wwyd.org/images/AR15/FAL_ARMS-mod (7) (Medium).JPG

http://www.wwyd.org/images/AR15/FAL_ARMS-mod (8) (Medium).JPG

[shootist~]

Bingo. That's the eye position you want - either the ARMS mount will hold it steady, or it won't. If it does, don't ever remove it for cleaning or any other purpose if at all possible - the slide in mounts get loose in a hurry. An easy test is when your iron sight groups are better than with the optic.

If you need additional clearance under the adj ring, it's easy as pie to mill down the rear lugs a little. A table top belt sander worked for me and I've even used a radial are saw. If the nub of the stop pin for the rear irons is touching, a file is an easy fix. Looks like you are close.

[shootist~]

Another option to keep in the back of you mind is the USO Single Point Ring. I played with one briefly and it seemed to do the job on a USO 1.5-6 (although a lighter optic would be preferred for a FAL).

They don't show it, but the lowest available is a .980":
http://www.usoptics.com/uso-gear/accessories/rings-and-mounts/spr-single-point-ring-30mm-l.html