Need help selecting scope rings for my raised rail LR-308

[bootcamp]

Hi all, I have a dpms lr-308 with a slab side upper receiver with a raised rail specifically made to accomodate optics. I have a vortex 6-24x-50 on the way in and I have no clue size scope rings to order. I want the scope as close to the receiver as possible. I don't have to worry about an fsb because there is only a gas block.

I'm thinking low rings but not sure about the 50mm size and if it will clear the rail on the end.

The scope is scheduled to arrive Friday and I'd like to order the rings today so it has a chance to arrive at the same time because I'd like to shoot it next weekend.

Thanks in advance for your guys' expertise!

 

[TonyAngel]

As close to the reciever as possible may not be a good thing. You still need to get your face in there to look through the scope. Remember, the stock on an AR is in line with the bore and is pretty high up. How much of a rise is that on your receiver rail? About 5/8"? If so, then you're probably looking at medium to high rings to get the proper height.

I don't think that the objective clearing the handguard is going to be a problem. You should be more worried about getting a good check weld that is comfortable. If the scope's too low or too high, shooting won't be much fun.

 

[Maverick223]

First, which scope is it...the old Crossfire (1in. tube), new Crossfire (30mm tube), or a Viper-PST? FWIW, you may have trouble dialing in if it is the first one and you intend to use it for long range shooting, IIRC the adjustment range is pretty limited (I don't believe the new version is quite as bad and the Viper has an excellent adjustment range).

WRT the rings, you will probably find medium height to be comfortable (and about as low as you want to go) depending upon your stock.

 

[Z-Michigan]

I have an LR-308B with the same height. You won't have an issue clearing the objective, so choose rings based on best height for cheekweld. You will probably be happiest with medium, but possibly high instead. I would either buy medium to start, or buy one set of each height and just plan to save the redundant set for another rifle.

Leupold Rifleman (weaver-style) rings are decent quality and don't cost much at $17 or so. For a big step up in solidity and not much more cost (but a little more hassle in the mounting process), take a look at Warne rings.

 

[TonyAngel]

I'll second the warne rings at about $30, they're hard to beat.

 

[Maverick223]

With regards to brand, I like the Weaver Tactical Rings for the money; if you want to spend a bit more I would recommend Armalite, American Defense, or LaRue (NOT ARMS) 1-pc. mounts because they afford an appreciable difference in stability over separate rings.

 

[TonyAngel]

The ADM and Larue mounts are nice, but I don't think the riser on this rifle is removable. Going with an ADM or Larue is going to put the scope way too high.

 

[Maverick223]

The ADM and Larue mounts are nice, but I don't think the riser on this rifle is removable. Going with an ADM or Larue is going to put the scope way too high.

Don't know about the mount from Armalite (the least costly of the three), but both LaRue and Am. Defense make medium height mounts (sub-1.5") as well as the standard high models so they should work fine if the OP is willing to forgo the added expense.

 

[TonyAngel]

You know, Maverick is right. I completely forgot that they make mounts for rifles other than ARs. I have a one track mind. If you can find a one piece mount that would definitely be the right way to go.

 

[Maverick223]

...if you can justify the expense (which for me would mostly depend upon the use).

I completely forgot that they make mounts for rifles other than ARs.

Not being an AR guy (I shoot other folk's, if that counts for anything), myself, those are the only mounts that I have much use for.

 

[madcratebuilder]

I'm looking for a mount for my AR10 and have considered the ArmaLite one piece and have looked at the Burris XTR one piece. Both are in the $70 area.

A few experienced AR10 shooters tell me to get a mount with 20moa built in so I can get the full potential of the rifle.

 

[Maverick223]

A few experienced AR10 shooters tell me to get a mount with 20moa built in so I can get the full potential of the rifle.

I concur, the only reason not to add cant is if the scope you plan to mount hasn't the elevation to zero. I like to have about 250% of the cant in elevation to ensure a good zero, in other words about 50MOA internal elevation for a 20MOA cant. I use a 40MOA tapered base, and whilst I will likely never have need of the additional elevation (it is enough to get me well beyond the 1mi. marker), it doesn't hurt anything.

 

[Z-Michigan]

My understanding from others here is that you generally don't want to use a scope at one end of the elevation range, so I would not get a 20 MOA base unless the scope is commonly going to be used with the crosshairs close to centered in their elevation range, i.e. zeroed or adjusted for a fairly distant (500-600+ yards) target. I also read on here that your windage adjustment will be a lot less when the elevation is at one extreme than it will be when elevation is roughly centered within the scope's range of adjustment.

In other words, a 20 MOA base is reasonable if you're doing exclusively mid-long to long range shooting, but not if most of your shooting will be inside of 400 yards.

If you do get a 20 MOA base, I would choose your scope carefully based on its elevation range, as scopes vary widely from >100 MOA to <50 MOA adjustment ranges, and that will make a big difference for how usable the scope and 20 MOA base combo is.

 

[Maverick223]

I also read on here that your windage adjustment will be a lot less when the elevation is at one extreme than it will be when elevation is roughly centered within the scope's range of adjustment.

The key is you need more windage at greater distance, so it actually works to an advantage because as you dial up you get more windage as well.

In other words, a 20 MOA base is reasonable if you're doing exclusively mid-long to long range shooting, but not if most of your shooting will be inside of 400 yards.

Agreed, none of my hunting or plinking rifles have tapered bases, there is simply no reason that I need them, and to be perfectly honest I like the looks of standard 2-pc. (dual dovetail or dovetail/windage) mounts better. Additionally there is added weight with a 1-pc. base, not an issue (and often a welcome addition) on a target rifle, but weight adds up quick when you are hiking.

 

[Z-Michigan]

The key is you need more windage at greater distance, so it actually works to an advantage because as you dial up you get more windage as well.

OK, that makes good sense. The only potential issue then is if you need to use up some of that windage in getting your initial zero. That shouldn't be an issue with the DPMS flat-top and any quality rings and scope. (It can be an issue with hunting rifles that have separate scope bases and may not have perfect alignment of bases to bore axis.)

 

[Maverick223]

The only potential issue then is if you need to use up some of that windage in getting your initial zero. That shouldn't be an issue with the DPMS flat-top and any quality rings and scope.

True and true (amongst many others).