Rifle Scopes 18" SPR Optic: Leupold Mark 6 1-6x20mm, or Mark 8 1.1-8x24mm CQBSS? Help requested.

[Snake Plissken]

Hey guys. I've got an 18" barreled AR set up with a TA31F 4x32 ACOG, a Magpul MOE Fixed rifle length stock, and a Magpul VFG, in sort of a pseudo-M16A4 set up.

I'd like to change it to an SPR configuration. This will include swapping out the fixed rifle length stock for the new Magpul FCS (Fixed Carbine Stock), replacing the VFG with an AFG to allow for a more traditional rifle hold that still offers a supported grip, installing my Harris bipod as far forward on the 6:00 rail as I can, upgrading the trigger to a Geissele SSA-E.

Of course, the ACOG is going to be switched out for a variable powered scope. I've narrowed it down to the two in the thread title: the Leupold Mark 6 1-6x20mm, or the Leupold Mark 8 1.1-8x24mm CQBSS.

Regarding the Mark 6, I've got questions about its 5.56 BDC CMR-W reticle:

1.) If the centered dot is meant to be zeroed at 50m, presumably, it would double for a 200m aiming point. The top of the Y axis in the reticle serves as the 300m BDC hold. Where is one supposed to hold for a 100m shot? Does one simpley hold the dot slightly above the intended point of impact? It's probably something stupid obvious/easy math like the 50/200m detail and I'm just missing it, but I can't see how one is meant to aim for 100m shots with how the reticle is presented.

2.) Seeing that the reticle is tuned for 62gr 5.56, how would it perform when using 75 or 77gr match type ammo? Personally, I'm a fan of BDC reticles, but I'm not sure how the hold compensations would change between each different ammo type being used with the same reticle. Would heavier ammo throw the whole reticle off, or would the differences in POA/POI be marginal/of little concern?

Regarding the Mark 8 and the M-TMR reticle:

Granted that this scope and the M-TMR reticle is meant (by the USMC at least) to be used with the M2 .50 and Mk19 Grenade Launcher, how well does it perform in regards to precision shooting? Is it in that case an improved TMR reticle what with its ranging features and BDC dials?

Like I said, these are the two I've narrowed it down to after extensive research of all available options. Any help in regards is appreciated.

 

[Andy T]

I did some quick math with JBM using .243 ballistic coefficient and muzzle velocity of 3030 ft/sec for a 55 gr .223 projectile. With zero distance set at 50 meters, it is supposed to impact 1.3" below POA at 200 meters and 1.2" above POA at 100 meters. This is one reason why a 100 meter/yard zero is preferred - you always hold over, and never have to worry about hold unders.
Personally, I would recommend a 1-6 with M-TMR reticle. Then you can make your own BDC by shooting various rifle ammo at distances and noting the impact shift.

 

[bm11]

I have the mk6 and it is sweet. The dot is zero'd at 200m, which is meant to be "close enough" from 50-200m. At 100, you hold dead on and don't worry about the 2" or less you are off.

That said, for a true "SPR," I would want the 1.1-8, if budget allows. The extra 2x for precision would be nice. The CMR-W is matched to m855 out of a 14.5" barrel. Good enough for most jobs, but not my idea of precision ammo. I'd want the 8x and the TMR reticle and I would dial my dope rather than holding it, if precision was paramount. Your call and your definition of SPR!

 

[ajwcotton]

From what I understand the TMR in the 1-8 is not red dot illuminated like it is on the H-27. So for me the choices would be between the 1-6 with the m-tmr or the 1-8 with the H-27. Other than that if the 1-6 doesn't do it for you and the mk8 is too expensive, the USO 1-8 is over 1K cheaper then the mk8 and very similar in features only lacking the horus ret.

 

[KiowaDriver]

The CQBSS H27 is it. Seriously. All of the other 1-6 and 1-8 are just trying to compete. The CQBSS is just really freaking expensive. That is its downfall. I love mine.

 

[Redmanss]

I have the mk6 and it is sweet. The dot is zero'd at 200m, which is meant to be "close enough" from 50-200m. At 100, you hold dead on and don't worry about the 2" or less you are off.

That said, for a true "SPR," I would want the 1.1-8, if budget allows. The extra 2x for precision would be nice. The CMR-W is matched to m855 out of a 14.5" barrel. Good enough for most jobs, but not my idea of precision ammo. I'd want the 8x and the TMR reticle and I would dial my dope rather than holding it, if precision was paramount. Your call and your definition of SPR!

Spot on response. I have the M-TMR CQBSS on my MK12, and it rocks it. Very good FOV, enough magnification for all of my long distance purposes with it, very quick on the turrets and since I shoot 77gr in varying environments, I don't want the ballistic reticle in there and definitely not one that is mismatched. It's a "critter-gitter" and long range steel banger in my usage while still being a walking rifle as well, albeit a stout one. If you don't expect to run it all the way down at 1.1x, then look to a different option as that is a feature that comes with a hefty price tag. If I was going to do it over, I would likely go with one of the Mark 6 3-18x44 for it. Still might...

I did just order a Mark 6 1-6x20 with the CMR-W for my 16" 308... Different application though; looking to try my hand at 3-Gun Heavy next year. I'm looking forward to playing with it this summer.

 

[Snake Plissken]

Redmanns, do you mind much that the reticle isn't illuminated on your CQBSS? Another thing that has me hesitant on the CQBSS, regardless of reticle, is that the BDC dials are tuned to 175gr SMG 7.62x51

 

[Redmanss]

I'm not room clearing with it so no, I'm not worried about having that single red dot, and I have an Aimpoint on my carbine (as well as my work rifle). Down to 1.1x, I am more than able to run hammer pairs on multiple targets while advancing, so I'm not worried about having the red dot feature like the Horus version has. The reticle is illuminated, just not on the center portion like a dot but on the outer posts so instead of a dot/doughnut style aiming point, I have a broken-T which works just fine as well.

As for the BDC dial, well you can get multiple rings for it so that is easily replaced, but all they have is a small reference number above the actual mil markings. It's a handy reference for you in the field, but I have DA drop/drift cards for my long range rifles anyhow.

 

[squinty-andy]

If you're going to run 75-77gr rounds, the 7.62 cmr- w is actually a much closer match than the 556. If you're really worried about it, you can still use a dope card (just like you would with a TMR) that lists exact corrected yardage for each numbered hash mark.

I've got a 1-6x cmrw, a 1.1-8x h27, and a 3-18x h58 with an offset t-1. There's a ton of overlap between them, but they basically break down like this for my uses (primarily on a 16" 7.62 gas gun):

1-6= lightest by a good bit, fastest up close, fast snap shots on IPSC torsos out to 600; further requires dialing because of lack of precise holds

1-8= heavier, fast up close with the h27, 12" plates out to 600, IPSC torsos out to 850-900, can be pushed out past 1100 with some dialing, can resolve bullet holes at 100m

3-18 w/offset RDS= close to the same weight as the 1-8, usable in a pinch up close, 12" plates out to 800, torsos to the max range of the round, can be used to self-spot misses and even trace in good conditions, can resolve bullet holes at 200m

I mean no offense to anyone who has the TMR, but IMHO if you're gonna drop the coin for the CQBSS, spring for the h27. It was purpose-designed for this application (rather than crew-served) and if you look around pricing has dropped out of the stratosphere.