Mounting scope spanning free float?

[cnp1234]

Did I search for this but I couldn't find much. I'm working on gathering up parts to do a really lightweight ar build and I'm trying to make a decision on a free float rail. I'm kind of torn between a Vltor CASV and a Troy TRX Extreme. I like the Troy TRX because of the weight, but the CASV gives me a long one piece top rail. I figure that allows me to cut down on weight by using rings if I mount an optic instead of a cantilever mount. It looks like I could just use rings with the TRX as well, but I'm not sure if that's a really bad idea or not as one ring would be on the receiver and the other would be on the free float tube. I've read one or two articles saying to avoid it, but has anyone actually tried it? If there were problems what were they? Just for reference, I'm thinking about getting a 1-4x GRSC scope, so it's not like I'm concerned about long rage accuracy and variations.

 

[rcmodel]

I don't understand your question?

I don't know of any 1-4x scope that is long enough to need the front ring out on the handguard.
Mounted that far foreword would put the scope clear out of eye relief range so you couldn't see through it.

Just mount it on the flat-top uppers rail where it is supposed to go.

rc

 

[Zerodefect]

Larue tactical has cantilever scope mounts. Lt104 I think is the most popular scope mount. You do not want to bridge that gap. And I really don't trust a full length rail bridge that can still get tweaked.

The thing is, you really need a quick release on a scope. If the glass shatters or a seal breaks allowing the scope to fog inside,........you might need to get that thing off in a hurry and get your BUIS up.

I like the Trijicon Accupoints 1-4x but it might be a good idea to use the extended relief scope mount, that scope has alot. It's easier to move it back than forward. I have a Trijicon 5-20x 50mm Accupoint scope. It rocks. But I have only a little experience with the 1-4x. I prefere Aimpoints and Eotechs on my fighting rifles because scopes can be tough to get lined up to my eye without "scope shadow".

Nightforce is the king of 1-4x tactical scopes, and the price shows it.

 

[cnp1234]

@rcmodel - The scope I'm looking at is this one: http://www.snapsling.com/combatriflescope.php. Judging by pictures here, http://home.comcast.net/~shooter2_indy/recon.html, the scope most certainly would have a ring on the hand guard rail if I mounted it with rings. That said, this will be my first AR build, so I probably don't know what I'm talking about.

@Zerodefect - Yeah I like the Larue mounts and everything I've read about them has been fairly positive. If I go with the Troy rails I guess I'll end up using one of those mounts. I think I found a third option just this weekend: http://www.megamachineshop.com/armscatalog/MTS-MODULAR/loader.html. This looks like it'd be a decent setup for me and I think worst case would only cost me a couple of ounces in weight. If I did that, I'd be sure to use QD rings in case of optics failure.

 

[rcmodel]

Judging by pictures here, http://home.comcast.net/~shooter2_indy/recon.html, the scope most certainly would have a ring on the hand guard rail if I mounted it with rings.

Well maybe.
It sure has a long eye-piece bell!!

rc

 

[PALMERJ]

Do not span from the upper to the float tube. Most times the float-tube is not lined up with the receiver and the spacing changes between the two, you could have problems or damage the scope.

 

[Double Naught Spy]

As you don't want to span the gap, one solution is to get a Colt Monolithic upper. The barrel is floated and the handguard is actually part of the receiver and so it has a continuos top rail with no gap.

 

[Marty B]

It appears that rifle may be set up to shoot with the stock in the shortest position. If the stock is the normal shooting position (longest) the scope would be moved back where it could be mounted normally on the receiver.