Hi
Just a dumb newbie question- What is a good rock-solid scope mount for a A2 upper. I have a Bushmaster with a A2 carry handle and would like to mount a nice scope that would be solid for some distant shots; I thought about swapping out to a flat-top but that's $$. Any suggestions appreciated.  

Here is one option that worked well for me:  www.armsmounts.com/catalog.php?action=124&item_id=74

You can get a brand new CMT flat-top upper for less then $100. Thats not a lot more then some good mounts for your A2 upper.

If you must use the A2 upper then the ARMS mount is a good way to go.

Word of Caution!

Out of the 2 mounts pictured above, I would personally try to find one that is built to Picatinny Specs (like the one posted by Henry455) versus Weaver / Stanag specs (like the one posted by CSGunWorks). Specifically you want the rail to have the low mounting groves along the complete surface like you will find with the Picatinny, not spaced far apart like you will find with the Weaver / Stanag.

I say this because the first mount I bought was one of the Weaver / Stanag types, and when I went to mount a set of rings I could not get the spacing to work out correctly. The low mounting grooves were either to close together or to far apart. I bought a mount with the Picatinny rail and then had no problems working out the spacing the way I needed it.

I would also recommend that you make sure that the mount has the “see through channel” so you can still use your iron sights. Some of the mounts are solid one piece construction and they will block the sight path of your iron sights.

Also, you may want to look at adding a cheek rest to your stock if you are going to mount your optics on the carry handle. It can be hard to get a good cheekweld on a standard stock with the optics being mounted so high up. The type of check rest that you will need to get will depend on what kind of stock you have.

I will get some pics of my carry handle mounting setups, and post them in the next day or two.

Good Luck,
“Capt Richardson”

Here are some pictures of one setup for an AR with a carry handle:





This allows you to use the EOTech with a good cheek weld, and you can drop down right below the EOTech and use the Iron Sights.

Hope this helps, good luck,
"Capt Richardson"

ARMS #2 + a good set of the lowest rings you can find.

For this I like nothing better than a Leatherwood type extended mount and Leupold (medium) rings.
Leatherwood Mount
Medium Rings

I've tried other mounts and always come back to the Leatherwood. It allows the scope to be mounted further forward.

The height of the rings you need are dependent on the scope. You might need the high rings (not the medium I linked) in order for the rear of the scope to clear the top of the mount. I usually keep a set of Low, Medium, and High rings on hand and pick whatever allows the lowest mounting and still clears. Sometimes it's the medium and sometimes the high. I don't recall the low ever working with any of the scopes I've put on ARs.

Quoted: The ARMS #2 is Picatinny Specs and the PM002 I’m told they are also.  The ARMS is the better of the two.  We have sold quit a few of both and no complaints.

Will that take a LaRue mount?

Last one I saw had the cutout down the middle so a LaRue could barely hold onto the outside edges. Obviously not a true picatinny.

Sorry,

Maybe I should have been clearer on the Picatinny versus Weaver / Stanag point that I was trying to make.

The big difference between the two that I was trying to point out was the number of grooves and the spacing between them. Per the picture below the ARMS mount has continuous grooves that are back-to-back, which gives you the greatest flexibility when it comes to mounting.



If you use the other type of mount the spacing between your rings is dictated by the larger spacing between the grooves.

Sorry I posted the EOTech setup instead of a standard scope setup. I will try to take or find some more that show some other good options for a scope.

If anyone else has any setups please post them.

Thanks for the feedback,
“Capt Richardson”

Quoted: I do not see how the center cutout will affect the LaRue’s grip on the rail.

Because that's where the LaRue is designed to center and hold, right in the middle. Then the clamp on the side tightens it up.

When the center is cut out the LaRue is unstable, or at the very least, it's hold on the rail is drastically weakened.

That's why I avoid so called picc mounts with the cutouts like the plague. I own a few and wish I didn't.

Quoted: ...The big difference between the two that I was trying to point out was the number of grooves and the spacing between them. Per the picture below the ARMS mount has continuous grooves that are back-to-back, which gives you the greatest flexibility when it comes to mounting....

That top mount also has the center cut out.  I've got to go search for my hated mounts before I can take pictures.

Notice that many manufactures of so called Picc mounts with the cut out center go to great lengths to hid this fact in the pictures they show of them. It's very deceiving.

Here we have a LaRue mount, a true Picc spec mount, and a center cutout quasi-Picc spec mount:




Notice that the LaRue mount holds in the center of the mount and is open on the sides:



The LaRue mount holds fine in the true Picc spec mount, but is only marginal in the quasi spec mount, if at all. At most it will be edges of one mount holding edges of the other. It is quite possible it would move under recoil or if the scope got a good whack.

The top mount is to the same true picc spec you see on AR flattop receivers.

As I said before, the maufacturers of these quasi-picc spec mounts try to hide the fact by only taking side photos of them where the center cutout is not visible.

The Nightforce looks like it's as open in the middle as the one I posted so it's a no-go. The Badger is looks less cut open and like it would hold a LaRue mount much better, maybe good enough, but it is still not to spec.

The piccatinny specs are listed here:
http://www.biggerhammer.net/picatinny/1913_specs.pdf

Notice that there is no cut down the middle.

My experience is that rails with the cut don't always work with LaRue mounts. Since the cut is not part of the specefications, rails with the cut are out of spec. That's one more reason I dislike and avoid them.

If what your are saying is right, just about everything on the market is out of spec and it's luck of the draw if one manufacturers product will fit anothers.

The middle cut on rails  is something that was added by some companies with the idea the rest of the rail mount still meets the spec. It does not have a full-length recoil lug because they cut the middle out.

LaRue does not have a full-length recoil lug on their scope mounts, but cut the sides off rather than the middle.

So the two approaches do not work together some of the time.

Perhaps the solution is to identify Picatinny mounts (both rail and scope) as "Center Cut Picatinny type" or "Outer Cut Picatinny type."

It would save me grief since I’ve bought a number of "Center Cut Picatinny type" rails because the deceptive side photos didn’t show the middle cut, and I couldn’t use them with LaRue scope mounts.  

To be absolutely fair about this, LaRue makes “scope mounts” that do fit on a true Picatinny “rail.” They are not making an out of spec “rail” like other companies are. So I have to blame the rail makers, not the scope mount.

First,
I have got to say thanks to Moguner1 for starting this topic, because while I thought I would be helping him out, I think the posts here have helped me out.

Second,
Thanks to everyone else who jumped in here. I have been looking at grabbing some LaRue Mounts to give them a try in place of the ARMS Mounts that I normally use. I had no idea that the recoil lug on them was only in the center. While 95% of the Rails that I have are what I would call “True Picatinny Spec” (back-to-back recoil grooves with no center channel), I do have one Rail/Riser that has the irregular recoil grove spacing and has the channel down the middle of it. I would be concerned about a LaRue Mount being able to move backward or forward on that Rail/Riser.

That’s the great thing about this place, with everyone helping everyone out a lot can be learned.

In regards to what is, or what is not, “True Picatinny Spec”, it is a Govt/Military Spec so good luck figuring it out. This does bring up a very good point that for the system to work, that there would not only have to be a spec for the Rail, but also a spec for the Mounts that go on the Rail. While I have seen the specs for the Rail posted all over the place, I have not seen the spec for a Mount that would go on the Rail. I guess this means that I will be doing some more research to try and find out more about the Rail and Mount specs.

Below is Picture of the issue that I was talking about earlier with the Recoil Groove Spacing.



With this Carry Handle Mount and this One Piece Scope Mount the two would not line up so I had to cut an extra Groove on the Carry Handle Mount. This is why I will now only buy the Mounts that have the continuous back-to-back Grooves.

Thanks again to everyone,
“Capt Richardson”

OK - So now I've also learned a lot. Maybe a little too much hereI've also toyed with the idea of replacing the A2 with a Flat-top receiver. And while it's torned down add free floating handguards (and a 2 stage trigger). Now I'm starting to get carried away
but in a good way!!
Anyone know someone in Missouri (near south St. Louis) who would be capable of this?
Thanks for the many replies and all the info!!  

It's pretty simple to do yourself with a few tools.

Ask for help in your Hometown forum and there will probably be a local or two with all the tools willing to help you. This is Arfcom after all.

Thanks for all the help - Merry Christmas and Happy Shootin' in the New Year !!