Rifle Scopes QD scope mounts: why?

[Slick66]

I've ended up with a number of QD mounts for my AR optics, low-power variables and red dots, and I am re-evaluating their relative pros & cons, wondering if conventional wisdom may have changed over the years.

What real practical benefits do lever-type QD scope mounts offer over other types (with other types I guess being those scope mounts/rings that require a tool to detach from the firearm)?

 

[Supergyro]

On my AR15, all my optics are in QD mounts. It's the only way to get it into the Pelican. I've found they reliably return to zero, with more than acceptable precision for that rifle's use. I probably wouldn't use them on my precision bolt gun, but that's an entirely different animal.

 

[19Scout77]

Other than to access buis, imo there really is NO good reason to use QD mounts on any platform.

 

[bjay]

I have a 6.5 grendel with NF scope set up for precision lng range with 26" satern..im using ad recon reason i went with this qd so i can move scope to other rifle while doind load development.. i set this qd where i can detach with both hand... while doing load development i could never get this satern barrel shoot good.. where id never seen this barrel shoot junk of all reviews.all in moa's or more i cant even get half moa changing powder seating depth bullets and playing with powder load.. so i asked people shooting precision on AR config majority using unimount or ring. Some using qd one thing ive learned when using qd on precision rifle tighten it up where you need extra tools to unlatch it.. not qd just with your hand.. now rifle shooting on how it supose to be..so im guesing heavy scope will make diff on my 3g 1-4scope it didnt so i leave it where i can detach ut with hand but not easy detaching

 

[farmerted]

What real practical benefits do lever-type QD scope mounts offer over other types (with other types I guess being those scope mounts/rings that require a tool to detach from the firearm)?

Storage in the safe.

 

[K_4c]

I only use them to get proper eye relief (2" extension) and to mount my BUIS...

 

[GhostFace]

Other than to access buis, imo there really is NO good reason to use QD mounts on any platform.

And if you are using a dedicated NV scope in addition with your day scope. We do this with our department issued 700s, I could not get the bosses to spring for a PVS-27 so we need NV and this was our next best option. I know some will argue or warn against QD mounts/rings but we have found they really do RTZ after many many tests...

 

[Flyboy22]

Umm, because some of us can't afford a S&B for ALL our rifles. Plus I have yet to see a downside... perfect RTZ so far.

 

[pinsandpitons]

Flyboy said it. That's exactly my situation. Plus I get to use the same scope on my precision rifle, AR, and .22 trainer. NEVER has it been anything but 100% repeatable going back and forth between platforms. Not even mid 10 shot group. I always push the scope forward till it contacts the groove in the picatinny before I tighten it, maybe that helps, but I don't buy into "screw down is better". Theories hold true till the first data point says other wise... I haven't seen that data yet.


Added:
I keep the scope zeroed to my precision bolt and adjust to the settings for the other guns, then back.

 

[19Scout77]

Even if switching between rifles, unless the zombies are banging on your door, or allen keys are illegal in you AO, whats the big hurry? Why the need for qd?

 

[pinsandpitons]

Because I can without suffering any downsides.

 

[Ben Dover]

Even if switching between rifles, unless the zombies are banging on your door, or allen keys are illegal in you AO, whats the big hurry? Why the need for qd?

Might be because some folks WANT them ?

 

[Darkside-Six]

Most of my rifles are all QD mounts. my EOTechs on all my M4/AR's all have them. Relatively speaking, in a combat/self defense situation and your battery dies in your optic or the glass gets busted then you can easily take the optic off in seconds and rely on the back up iron sights. As for precision rifle, it makes it a lot easier when you travel. I take my glass off and carry it with me instead of in the case when I fly.

 

[Erud]

I have a 6.5 grendel with NF scope set up for precision lng range with 26" satern..im using ad recon reason i went with this qd so i can move scope to other rifle while doind load development.. i set this qd where i can detach with both hand... while doing load development i could never get this satern barrel shoot good.. where id never seen this barrel shoot junk of all reviews.all in moa's or more i cant even get half moa changing powder seating depth bullets and playing with powder load.. so i asked people shooting precision on AR config majority using unimount or ring. Some using qd one thing ive learned when using qd on precision rifle tighten it up where you need extra tools to unlatch it.. not qd just with your hand.. now rifle shooting on how it supose to be..so im guesing heavy scope will make diff on my 3g 1-4scope it didnt so i leave it where i can detach ut with hand but not easy detaching

I didn't understand a single word of this reply.

Not one.

 

[bjay]

I didn't understand a single word of this reply.

Not one.

Sorry bro.. english is my second language and im using my cp.. a lot of it is missed typ on letters.. i hope someone did and can explain what i meant..anyway, if youre not planing to use one scope/red dot into multiple rifle NO i wouldnt recomend qd..i would get unimount or fixed mount/ring.. good luck

 

[Bounce]

QD because:
1. Transport
2. Storage
3. Multiple rifle use
4. Scope failure
5. Good ones allow RTZ
Skip

 

[TimK]

I clean my ARs in a parts washer. It's very fast and does a great job. It would be difficult and maybe impossible with the optic attached. I also like being able to snap a high powered optic onto a rifle that usually carries something lower powered for load development and testing.

 

[Slick66]

Thanks for the replies.

I actually should have asked about "performance" benefits, rather than "practical" benefits, since the practical benefits, such as using on multiple rifles and removal for transport or storage don't apply in my case.

But with regard to those benefits, isn't it just as easy to remove the mount with a tool, given that there isn't likely to be time pressure in those cases? Do QD mounts RTZ when removed better than those that require tools?

But the only performance benefit I can see to QD mounts is removing them quickly to access BUIS if the scope is damaged to the point you can't see through it, or if the scope/mount itself prevents deployment of the BUIS (flip-up). And the only time you'd need to do that quickly would seem to be in combat or competition.

I ask because I have several Larue QD mounts that have marked up the underside of receiver rails. A couple of them are on monolithic receivers, so the reason for using the cantilever mounts originally, lack of eye relief, no longer exists. I don't know if the mounts will eventually damage the upper (right now it just looks cosmetic), but unless I am getting some benefit from using them, I don't really want to risk it.

Just want to make sure I am not overlooking some benefit to using them.

 

[Jon A]

I'll offer a contrary opinion.

1) For most of the reasons people mention for the use of QD mounts one can do the exact same thing with bolt on mounts--just use a wrench. If you're going to the range and plan to swap scopes around...why wouldn't you bring a torque wrench? For cleaning and storage at home...do they not have a wrench at their houses either? And for some mounts which can be removed with a small L wrench kept in a compartment of your rifle's stock (yes, wink, wink) in the case of a broken scope you can remove it to use your BUIS in a few seconds no matter where you are, even if all you have with you is your rifle. So unless the charging zombies are only 20 yds away and closing fast, it's just not an issue for most people.

2) My experience has shown most of those who think they are suffering no downsides really are but simply don't know it. With an accurate enough rifle and methodical enough testing, it can usually be shown. The biggest problem is most typical QD mounts set up the way most people set them up only put around 1/10th the clamping force on the rail a good bolt on mount will. This is why the first shot of a group after reinstalling the mount is often a flier, especially with rifles of more recoil than the 5.56. The scope actually moves a significant amount under the recoil of the first shot.

But if you push it all the way forward while mounting this isn't an issue, right? Well sure, just be careful not to accidentally thump the butt of the rifle on the ground (easily generating more g-forces than the recoil of most AR's--only the other direction), shifting the scope backward again. So, if the rifle gets handled a bit more roughly than your typical range-queen it's something to think about. How about big magnums with a brake generating negative g's with every shot? Some of my customers with Barretts and DTA's were having fits trying to get them to shoot until getting rid of their QD mounts.

Don't get me wrong, I know there are applications where a QD mount is a better choice. Swapping with NV gear as some brought up above, or if there really is a good chance somebody will be shooting at you when you break your scope so every second counts, sure. And for the vast majority of AR owners, especially 5.56's, with a 1.5 MOA rifle that's never used beyond 300 yds, frankly they're never going to notice the difference.

Anyway, there' some more things to think about when making the choice.

 

[Cobracutter]

This. 100% Spot on.

Also wanted to add one thing. Reliability. Not only are they more moving part to fail, some designs like Larue WILL shift over time, and shoot themselves loose. Some also don't have a very good bearing surface and your $3K optic is being held on by a sliver of metal.

Take a look at the SEAL work guns. All most all of them will use a KAC or other 1 Piece NoN qd mount with their 3-15x's.

I live by the rule, if its a carbine or anything I am not shooting for groups/accuracy or I am running 1-4/1-6 or a RDS, than the shift is negligible. If you are running higher magnification on precision applications, even the best QD mounts like Bobro and GDI will have some measurable shit. How much is acceptable to you is another story.

For the Price of a 34MM Bobro or GDI, you can have a SPHUR mount, KAC 1 piece or a Badger 1 pieces at less than half the price.


If you really need to swap guns, then invest in a good torque wrench like Borka and take of/reinstall propperly. You are going to need to rezero anyway, so its a moot point.

I'll offer a contrary opinion.

1) For most of the reasons people mention for the use of QD mounts one can do the exact same thing with bolt on mounts--just use a wrench. If you're going to the range and plan to swap scopes around...why wouldn't you bring a torque wrench? For cleaning and storage at home...do they not have a wrench at their houses either? And for some mounts which can be removed with a small L wrench kept in a compartment of your rifle's stock (yes, wink, wink) in the case of a broken scope you can remove it to use your BUIS in a few seconds no matter where you are, even if all you have with you is your rifle. So unless the charging zombies are only 20 yds away and closing fast, it's just not an issue for most people.

2) My experience has shown most of those who think they are suffering no downsides really are but simply don't know it. With an accurate enough rifle and methodical enough testing, it can usually be shown. The biggest problem is most typical QD mounts set up the way most people set them up only put around 1/10th the clamping force on the rail a good bolt on mount will. This is why the first shot of a group after reinstalling the mount is often a flier, especially with rifles of more recoil than the 5.56. The scope actually moves a significant amount under the recoil of the first shot.

But if you push it all the way forward while mounting this isn't an issue, right? Well sure, just be careful not to accidentally thump the butt of the rifle on the ground (easily generating more g-forces than the recoil of most AR's--only the other direction), shifting the scope backward again. So, if the rifle gets handled a bit more roughly than your typical range-queen it's something to think about. How about big magnums with a brake generating negative g's with every shot? Some of my customers with Barretts and DTA's were having fits trying to get them to shoot until getting rid of their QD mounts.

Don't get me wrong, I know there are applications where a QD mount is a better choice. Swapping with NV gear as some brought up above, or if there really is a good chance somebody will be shooting at you when you break your scope so every second counts, sure. And for the vast majority of AR owners, especially 5.56's, with a 1.5 MOA rifle that's never used beyond 300 yds, frankly they're never going to notice the difference.

Anyway, there' some more things to think about when making the choice.

 

[Slick66]

Again, thanks for the replies.

I have a LMT MRP with 16" 5.56 SS, using a LT-104 with a S&B short dot. I was replacing it after using a RDS when I noticed the marks left on the receiver by the lever cam. Like I said, the marks appear to be cosmetic only. There was a little slop in the levers that I tried to eliminate by tightening with the wrench in small increments, but I was getting the feeling that more tightening was crushing rather than tightening. The whole exercise didn't leave me with a lot of confidence, and prompted the question about the need for QD.

Because of the monolithic receiver, I was thinking of switching to Badger ultra-high alloy rings and some kind of offset BUIS. Any reason not to go with that set-up?

That leaves me with a TR-24 in another LT-104, on a Colt M4 upper. Are there any quality non-QD one-piece mounts that will give me enough eye relief?

Thanks again for all the help.

 

[30calDeath]

I can take off my Spuhr and reinstall it again in 30 seconds or less and that is all four of the bolts torqued. I bring my Borka tools kit with me where ever my AR goes and it is just so quick to take it off and reinstall it again.

I do understand about the BUIS if your optic fails due to physical damage but me personally that will only happen if the Zombie apocalypse occurs.