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Discussion Starter · #1 ·
Someone in a local store told me I would need to install HK flip up sights if I wanted to use them with an Eotec or Aimpoint. Is this correct? If not which would you use?
 

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I used my EOTec in Iraq with the run of the mill MI sights and never had any issue. If they're dead set on you buying those and they can't demonstrate why it's the ONLY sight that would work with your optics, I'd start shopping for a new dealer as that sounds kind of hokey. Troy Industries has a new sight out that's kind of interesting you might want to look at if you're planning on spending HK amounts. It's a diamond sight-instead of having the round aperature, you'll be looking through a diamond. It's still new but seems to be getting good reviews and actually makes a lot of sense.
 

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Your dealer doesn't know "Jack $hit". The height of the XCR top rail doesn't mean anything as the BUIS and Aimpoint or EOThingy sit on the same plane which is the top rail. The only factor you have to worry about is if you want an absolute co-witness or lower one third co-witness and that factor is determined by the spacer height of your optic. The height of the top rail on the XCR like the HK is higher than a standard AR upper. So if you are used to your stock sitting high on your cheek and wanted that same feel with the XCR you would use lower HK sights. If you don't care about the XCR stock sitting lower on your cheek then higher or standard AR BUIS work just fine.

MadDog :duh:
 

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Discussion Starter · #4 ·
Thanks for the help! Yeah, I really don't care where it sits on my cheek...just something that works :) Sounds like that will be easy to find!
 

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I handled the (Not sure how new they are) YHM push button pop up BUIS and they are really nice for a fraction of the Troys etc..

Doug's is selling sets for $200.
 

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Someone in a local store told me I would need to install HK flip up sights if I wanted to use them with an Eotec or Aimpoint. Is this correct? If not which would you use?
I have the Troy BUIS and an Eotec on my XCR. They co-witness fine.

SheepDog :2rifle:
 

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Thanks for the help! Yeah, I really don't care where it sits on my cheek...just something that works Sounds like that will be easy to find!
Don't take this wrong but you should care. ;D To get proper eye alignment with your optics or sights your cheek weld needs to be consistant.I think the point is the XCR stockline is lower in relationship to the optical plane mounting rail than on an AR.That being the case if you mount regular AR irons you will tend to be looking low through the sights when shouldering the rifle normally.That why some XCR users are looking for lower BUIS's.
So you either need to get lower sights or a cheek riser.All this is dependant on multiple factors,thickness of your cheek,what stock you're using,what hight scope mounts etc.The whole idea here is you don't want to have to find the sweet spot everytime you shoulder the weapon,if the rifle/aiming device mount fits you properly you will be able to consistently get into your scope or irons without repositioning.The speed gain in aquiring your sight picture being the gaol.If your mounting an optic,especially a magnified one,keep it as low as possible.
 

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Thanks for the help! Yeah, I really don't care where it sits on my cheek...just something that works Sounds like that will be easy to find!
Don't take this wrong but you should care. :DTo get proper eye alignment with your optics or sights your cheek weld needs to be consistant.I think the point is the XCR stockline is lower in relationship to the optical plane mounting rail than on an AR.That being the case if you mount regular AR irons you will tend to be looking low through the sights when shouldering the rifle normally.That why some XCR users are looking for lower BUIS's.
So you either need to get lower sights or a cheek riser.All this is dependant on multiple factors,thickness of your cheek,what stock you're using,what hight scope mounts etc.The whole idea here is you don't want to have to find the sweet spot everytime you shoulder the weapon,if the rifle/aiming device mount fits you properly you will be able to consistently get into your scope or irons without repositioning.The speed gain in aquiring your sight picture being the gaol.If your mounting an optic,especially a magnified one,keep it as low as possible.
I agree....which is why I spent the money on Troys first and found them to be too tall (and I didn't want to change the stock b/c the tube folder is so damn nice) so I ended up spending even more money on a set of HK diopters (non-folding) irons to use with an HK height LaRue Micro T-1.

My next XCR will be using the Troys I bought, but with an RA fixed stock adapter, UBR, #2 Magpul cheek riser and probably a scope.

I just couldn't get the right sight picture with the factory folder without going to shorter irons and since every iron set I could find was for an AR except the HK, I went HK.

JME,
Sean
 

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I understand.I mounted a small 2x6x26 on mine a short time back in a set of low rings.Now even with the M4 style Caa stock it's pretty good,heigth wise.I like the HK sights but I'm not going to drop that kind of coin on backups that I can't have mounted with the scope at the same time anyway because they interfer with the view of the scope.Besides with my eyes,I'm not that hot with irons very far out anyway.If RA don't release their stock or at least pics of it soon,(HINT ;D HINT ;D DAMNIT!!)I'll probably bite the bullet and get a UBR.I like how the rear of the stock moves not the outer sleeve like on a regular M4 style.It would provide a more solid cheek weld because you don't have two sections inside one another,and when/if you mount a cheek riser it won't move to the damn rear of the stock when you adjust it out!!!
 

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I FINALLY got my HK diopters today (long story involving incompetence at the post office).....

Anyway, honestly, I wish Troy made 1/2" shorter versions. The HKs are nice, but for my apparently grotesquely too long of neck/arms the sight picture with them set on 1 is basically a giant hole with the front sight post swimming around in it.

I may just have to move it farther forward on the upper rail. They look plenty stout (since they don't fold....which isn't a big deal now on this XCR since I'll be SBRing it hopefully and using a T-1), but the "prongs" on the front sight are spread a little far apart (compared to what I'm used to) and the rear holes are enormous where I currently have it mounted on the upper rail.

Can anyone think of any reason I couldn't just roll the drum on the rear diopter to the 3 or 4 position and zero the rifle with the rear diopter in that position (to take up the excess space around the front sight post)? Since the HK diopters are set up for a bullet drop compensator based on which hole you choose (I'm assuming it'll be different for my 6.8 SPC conversion anyway), I know rotating the drum will move the POI to compensate....just don't know what I'm doing.....as usual. ;D

Sean

PS. DTOM, I have the UBR already, but the #2 cheek riser is on backorder from Magpul for a "few weeks" according to them today....JIC you need to know. As I'm sure you know....the UBR is pretty hefty, I think over a pound.....balances the rifle nicely though....just adds even more weight.
 

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On another note....my problem with the Troy sights may have been mostly the entry stock I have on my first XCR.

I just bought a 2nd XCR today and it has the longer 13" LOP folder.....with the Troys installed, it's pretty use-able. The sights are a little bit high, but not bad compared to the shorter stock on my other rifle.

Not sure if I'll use the UBR and cheek riser now or not. Even though I don't care for the looks of the folder, it sure is a solid design....I'm contemplating keeping it and either selling the UBR or putting it on one of my ARs.

So, in short, if you are having a sight picture problem with regular "AR height" BUIS, it may be just your LOP....swapping stocks may be another option.

HTH,
Sean
 

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So, in short, if you are having a sight picture problem with regular "AR height" BUIS, it may be just your LOP....swapping stocks may be another option.
No I have an adjustable stock on mine so that's not it,but I appreciate the thought.I just had a brainstorm(well maybe)I wonder if some some pipe insulation like you buy for plumbing might work to wrap the factory tube folder with to give you an increase in height.it comes in black so it might not look to hideous.It's just a thought.
 

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So, in short, if you are having a sight picture problem with regular "AR height" BUIS, it may be just your LOP....swapping stocks may be another option.
No I have an adjustable stock on mine so that's not it,but I appreciate the thought.I just had a brainstorm(well maybe)I wonder if some some pipe insulation like you buy for plumbing might work to wrap the factory tube folder with to give you an increase in height.it comes in black so it might not look to hideous.It's just a thought.
I think there was a thread about someone doing that before and I believe after they put the insulation on they actually wrapped it in a tape of some kind but I am not sure
 

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I think there was a thread about someone doing that before and I believe after they put the insulation on they actually wrapped it in a tape of some kind but I am not sure
That's very possible,hell in the back of my aging brain is maybe where I got the idea.I wouldn't want to try to take credit for anyone else's idea.Electrical tape(black unless your into funky patters 8))would not look bad I'm sure just to hold it all together.
 

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I think there was a thread about someone doing that before and I believe after they put the insulation on they actually wrapped it in a tape of some kind but I am not sure
That's very possible,hell in the back of my aging brain is maybe where I got the idea.I wouldn't want to try to take credit for anyone else's idea.Electrical tape(black unless your into funky patters 8))would not look bad I'm sure just to hold it all together.
or some of the black duct tape would look good, but then you would have the texture of it
 

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So, in short, if you are having a sight picture problem with regular "AR height" BUIS, it may be just your LOP....swapping stocks may be another option.
No I have an adjustable stock on mine so that's not it,but I appreciate the thought.I just had a brainstorm(well maybe)I wonder if some some pipe insulation like you buy for plumbing might work to wrap the factory tube folder with to give you an increase in height.it comes in black so it might not look to hideous.It's just a thought.
The problem is the space between the lower tube and upper tube...it's pretty minimal so I doubt you'd get much height from just wrapping....though you could add foam on top and then tape through the space between the two tubes.

I've got another idea though to get a 1/2" cheek riser and keep the folder. I thought I had enough material (I'm using 1x1.5x8" of 6061-T6 bar stock) but turns out I had just shy of what is required for what I'm dreaming up.

Originally I thought about ABS, but I don't think they make a 5/8" ID pipe. I considered a plastic welder too....but then the aluminum or steel avenue became more obvious....but I can't weld aluminum since I don't have a spool gun for my MIG and don't own (or know how to use) a TIG.

I have access to a mill/lathe at work, so I'm gonna try and machine a one piece unit that just slides over the upper tube on the stock, doesn't block the ejection port when folded, and uses either set screws or a couple of roll pins to hold it in place on the upper tube. I'll iridite the raw aluminum, use some zinc chromate primer for the AL, and then hit it with something durable for the top coat (black). How good is "gunkote"? I've never used it. Any recommendations on a good paint? I've got an abundance of CARC Aircraft black (and green) at work, but that stuff really scuffs quick.

I probably won't be able to work on it until next weekend though.

Sean
 

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Discussion Starter · #17 ·
Before my XCR order goes in, are any of the folding stocks better for using standard AR BUIS? I don't mind paying for the Troy if I have to, but I'd rather go with YHM if I could.
 

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Before my XCR order goes in, are any of the folding stocks better for using standard AR BUIS? I don't mind paying for the Troy if I have to, but I'd rather go with YHM if I could.
Troy and YHM will be identical in height....they are for a standard AR upper....there's no need to spend the money on Troy's unless you prefer them.



If you get a CTR (For example) you could then get the 1/2" cheek riser from Magpul and that would get you high enough to have the same sight picture as a standard AR BUIS. The problem is: if you get the factory tube fixed folder....you may decide (like I did) that it's just too damn nice to get rid of, in which case....HK diopters are the right height.

HTH,
Sean
 

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So, in short, if you are having a sight picture problem with regular "AR height" BUIS, it may be just your LOP....swapping stocks may be another option.
No I have an adjustable stock on mine so that's not it,but I appreciate the thought.I just had a brainstorm(well maybe)I wonder if some some pipe insulation like you buy for plumbing might work to wrap the factory tube folder with to give you an increase in height.it comes in black so it might not look to hideous.It's just a thought.
The problem is the space between the lower tube and upper tube...it's pretty minimal so I doubt you'd get much height from just wrapping....though you could add foam on top and then tape through the space between the two tubes.

I've got another idea though to get a 1/2" cheek riser and keep the folder. I thought I had enough material (I'm using 1x1.5x8" of 6061-T6 bar stock) but turns out I had just shy of what is required for what I'm dreaming up.

Originally I thought about ABS, but I don't think they make a 5/8" ID pipe. I considered a plastic welder too....but then the aluminum or steel avenue became more obvious....but I can't weld aluminum since I don't have a spool gun for my MIG and don't own (or know how to use) a TIG.

I have access to a mill/lathe at work, so I'm gonna try and machine a one piece unit that just slides over the upper tube on the stock, doesn't block the ejection port when folded, and uses either set screws or a couple of roll pins to hold it in place on the upper tube. I'll iridite the raw aluminum, use some zinc chromate primer for the AL, and then hit it with something durable for the top coat (black). How good is "gunkote"? I've never used it. Any recommendations on a good paint? I've got an abundance of CARC Aircraft black (and green) at work, but that stuff really scuffs quick.

I probably won't be able to work on it until next weekend though.

Sean
Well, spent 3 hours today working on this project......decided to go with the shorter piece of AL stock I had on hand.

The first 1.5 hours went perfect....went from a big chunk to a formed chunk of AL.

Then the toughest part. My work doesn't have the right equipment to bore a 5/8" hole 5".....so I decided (like a moron) to try it on my drill press at home.....disaster.

Spent 1/2 hour setting everything up....spent an hour trying to get a super long bit to drill straight....tried from both ends, tried short bits, long bits, different sizes, different jigs.....just don't have the right kind of equipment for this job.

I haven't given up yet as this design shows some promise....I'm trying to find a machine shop tomorrow that can bore this hole. If that goes well.....it should be pretty easy to finish up. Pretty sure I'll have to start over on a new piece of stock this time.....I tried drilling from both ends with the shorter bits....and, you guessed it....the holes didn't meet as planned.

Sean
 

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Someone in a local store told me I would need to install HK flip up sights if I wanted to use them with an Eotec or Aimpoint. Is this correct? If not which would you use?
I have the Troy BUIS and an Eotec on my XCR. They co-witness fine.

SheepDog :2rifle:
Yup. Practically perfect.

tk
 
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