Video: LT660 mount re-zero capability

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03-25-12, 22:49
chadil1ac

Quote:

Originally Posted by a0cake

A while ago I tested RTZ for quite a few mounts including ADM, Larue, Bobro, and GG&G. There's a surprising amount of emotion out there regarding this equipment so I wanted to make my own determinations. For me, Bobro was the only mount that showed no observable shift. At the risk of sounding like a prick, I'll say that I'm an honest 1/2 minute shooter and so was the gun (this way the driver and race car can't get blamed).

I don't have the hard data (I'll see if I can find my old range book), but ADM and Larue were also very good as far as RTZ goes (less than 1 minute, with the ADM being closer to 1/2). The Bobro did not move though.

NOTE: I've not had a great deal of experience with GoDI mounts, but shooters that I trust more than any online personality tell me they're just as good as Bobro in this respect. Can't comment first hand though.

Honestly, where the Bobro wins me over is the auto-indexing feature. I routinely move optics around from rifle to rifle. With the Larue, this would often require re-tensioning of the locking mechanism and certainly induce zero problems. The Bobro, however, RTZ's not just on one rifle, but from gun to gun (obviously after I adjust the optic to a predetermined point), each with slightly varying rail slot dimensions. No adjustment required.

Bottom line: forget all the emotional hyperbole over these mounts. I use what works and don't care what's inscribed on it. My testing lead me to Bobro. If Mark comes out with a new system that outperforms the Bobro in some respect, I'll gladly switch over.

Take it for what it's worth.

Thanks a lot for the info. That is good to know. The LT660 fits me for what i want in this rifle. I know Bobro makes some great mounts but didn't know they were that good. Something to think about for a long range build in the future.

Like you, I likf to test things myself. I do all my own gunsmithing and am basically a do it yourself type. This test was not planned ahead if time, it was just on a whim because I wanted to try it myself. Maybe it proves jack%&#@ but it was still fun. I am going to do some testing at longer ranges and with a little smaller target to try to get some good results.

Again, thanks for the comment. Always welcome.

BTW, 1/2 moa seems like some pretty good shooting. Any tips :D
03-25-12, 23:49
chadil1ac

Quote:

Originally Posted by C4IGrant

I hate to be the bearer of bad news, but I have to say a couple things.

First, you are shooting a 1.5-2MOA rifle. It has an optic with a 4MOA dot on it. The ammo you are shooting is only capable of 2-4MOA at 100yds. On top of this, you might only be a 2MOA shooter yourself (this part is just a guess and you might actually be a half inch shooter).

So the question is, how would you know that your mount has returned to zero?

C4

Disclaimer: not trying to prove a point or that my video shows true awesomeness :confused: just asking a question...

Alright, so after thinking about this, let me just ask if this would be true or make sense. It probably doesn't but let me give it a shot. Grant and a0cake, you seem to know a lot more about this stuff and could probably figure out what I am trying to say. I am only a lowly 26 year old with about 4 years of actual shooting experience.

This is all just conjecture and not based on true facts but hypothetically...

You mention that the gun is about a 1.5 - 2 moa shooter. Makes sense, it wasn't built for precision. Also, the ammo is 2 - 4 moa. Call it 3 average. Say I am a 2 moa shooter (just measured some old targets, looks like I can hold a 1.5" group or less with the Aimpoint at 50 yards so 3 moa with a 3.5 moa red dot so I think I could probably hold a 2" group at least with a precision gun). All of that is equal to 6.5 moa.

So, I am shooting off hand which changes my accuracy some. I don't know by how much but I would guess that I could probably keep a 6-8" group, 5 rounds at 100 yards off hand so lets say it is 7 moa. 6.5 moa + 7 moa = 13.5 moa. The plate is 20 moa. Would it be safe to say that this test proves that it has the capability of staying zeroed up to 6.5 moa of poa?

I am sure it is capable of better but just looking at the test I did, would that make sense? If not, I just have no idea what I am talking about and just need major help...:dirol:
03-25-12, 23:56
bsmith_shoot

I think that maybe we're confused on what the optic/mount is made to do.
In my opinion, this combo isn't made to be removed, then remounted and used to shoot benchrest groups, it's made to be remounted and still get combat effective hits.
I don't shoot to get 1/2" at 100 meters, I shoot as often as I can, to get high center chest hits with every round I shoot. This is done to protect my family.
ADM, LaRue, Bobro, DD, GG&G, etc.... are all capable of that.
If you wanna test a mount for accuracy, do it with a optic that is designed for it. This is just my opinion, and i'm nothing in this big old world of combat weapons and gear. I just do gigs as a glorified mall cop. :-)
Brandon
03-26-12, 12:45
drck1000

Quote:

Originally Posted by a0cake

A while ago I tested RTZ for quite a few mounts including ADM, Larue, Bobro, and GG&G. There's a surprising amount of emotion out there regarding this equipment so I wanted to make my own determinations. For me, Bobro was the only mount that showed no observable shift. At the risk of sounding like a prick, I'll say that I'm an honest 1/2 minute shooter and so was the gun (this way the driver and race car can't get blamed).

I don't have the hard data (I'll see if I can find my old range book), but ADM and Larue were also very good as far as RTZ goes (less than 1 minute, with the ADM being closer to 1/2). The Bobro did not move though.

NOTE: I've not had a great deal of experience with GDI mounts, but shooters that I trust more than any online personality tell me they're just as good as Bobro in this respect. Can't comment first hand though.

Honestly, where the Bobro wins me over is the auto-indexing feature. I routinely move optics around from rifle to rifle. With the Larue, this would often require re-tensioning of the locking mechanism and certainly induce zero problems. The Bobro, however, RTZ's not just on one rifle, but from gun to gun (obviously after I adjust the optic to a predetermined point), each with slightly varying rail slot dimensions. No adjustment required.

Bottom line: forget all the emotional hyperbole over these mounts. I use what works and don't care what's inscribed on it. My testing lead me to Bobro. If Mark comes out with a new system that outperforms the Bobro in some respect, I'll gladly switch over.

Take it for what it's worth.

a0cake,

In your testing & evaluation, were you using red dots, lower power maginified optics, other? Just curious as I am also looking to use my optics for multiple rifles, particularly for the red dots and possibly a 1-4x.

I have a 2 MOA T-1 with the Larue QD mount and I am planning on trying a test like shoot to confirm zero, remove and remount and check POA/POI after that. I expect to still be in the vicinity at 50 and 100 yards, but I don't think I am a good enough shooter to attribute any shifts as due to the mounting method. Then eventually I'll try moving to another gun and see how it does.
03-26-12, 13:34
globeguy

Quote:

Originally Posted by chadil1ac

The distance was 50 yards give or take and the target was AR500 plates 10" in diameter.

http://www.youtube.com/watch?v=boIxp...-Xq3nCJqRC-Yk=

It could be the focal length of the cam playing tricks on me, but that doesn't look anywhere close to 50 yards to me.
03-26-12, 13:45
chadil1ac

Quote:

Originally Posted by globeguy

It could be the focal length of the cam playing tricks on me, but that doesn't look anywhere close to 50 yards to me.

It does look shorter than that. It is weird looking, there is kind of a valley in between me and the target. If you count my steps back, it's 30 from where I threw it to where I shoot it.

Could be a touch less. We walked it off as I forgot my laser that day...

50 yards should be about the far side of my truck. It looks like I was shooting a bit inside of the far side of the truck.

I want to explore this further though and do some testing at 100 yards. I will be going to a range for that so I can bench rest it. I will bring a laser too.
03-26-12, 15:35
a0cake

Quote:

Originally Posted by drck1000

a0cake,

In your testing & evaluation, were you using red dots, lower power maginified optics, other? Just curious as I am also looking to use my optics for multiple rifles, particularly for the red dots and possibly a 1-4x.

I have a 2 MOA T-1 with the Larue QD mount and I am planning on trying a test like shoot to confirm zero, remove and remount and check POA/POI after that. I expect to still be in the vicinity at 50 and 100 yards, but I don't think I am a good enough shooter to attribute any shifts as due to the mounting method. Then eventually I'll try moving to another gun and see how it does.

Nightforce F1. I'm not sure that I would have been able to observe and confirm POI shift with any degree of certainty with a RDS if said shift was at or around 1 MOA or below.
03-26-12, 15:55
drck1000

Quote:

Originally Posted by a0cake

Nightforce F1. I'm not sure that I would have been able to observe and confirm POI shift with any degree of certainty with a RDS if said shift was at or around 1 MOA or below.

Roger! That's kind of what I was thinking, but just thought I'd verify.

I will be happy if I am in the same general vicinity after remounting the red dot at 50 and 100 yards. Hopefully still on paper at least as those ranges. Then the next test after that is 16" x 16" steel at around 250 yards.

Your observations on Bobro is interesting. That's not the first time I've heard feedback/reviews on those like that.

In your POI shifts in remounting, so you notice that the majority of the shirts are in a given direction? Are most of the POI shifts more elevation or windage? If most of the shift is consistently elevation, I think that would be easier to account/adjust for. But I suspect that the shift will be all over due to slight variation on mounting methods. Something that I have in my notes to keep track of when I do these experiments for myself.
03-26-12, 17:03
wingspar

I love that you threw the optic. Wasn’t expecting that. To me, 50 yards is iron sight distance. Try it again on paper with a bench rest. The results will be better. However, you still hit it all 10 times after remounting the optic, so that does say something about what red dots are designed to do, which isn’t getting ½ inch groups at 100 yards.

I have one question. I have an AR 550 steel plate, and 5.56 did damage to it at 75 yards. I have to wonder what those rounds did to your steel plate at 50 yards?
03-26-12, 19:29
chadil1ac

Quote:

Originally Posted by wingspar

I love that you threw the optic. Wasn’t expecting that. To me, 50 yards is iron sight distance. Try it again on paper with a bench rest. The results will be better. However, you still hit it all 10 times after remounting the optic, so that does say something about what red dots are designed to do, which isn’t getting ½ inch groups at 100 yards.

I have one question. I have an AR 550 steel plate, and 5.56 did damage to it at 75 yards. I have to wonder what those rounds did to your steel plate at 50 yards?

I took a picture of the steel plate. I am in class though and can't post it from my phone. I will load it up later tonight or tomorrow.

It looks like it is making about a 1mm dent. It still should last for a while. A 9mm does nothing physically to the metal but does visually make a mark.

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