Troy low height BUIS poll

[Cid1911]

I'm curious as to the number of Troy low height BUIS owners that had to modify their sight detents or front sight posts. If you did have to modify your sight, please post the type of modification that was required.

[DSM]

No, zeroed at 200yds with room to spare.

[Sean K.]

I had to shorten the plunger and spring on my Troy Micros (stubbies)....I posted the exact amount in another thread.

Had to do the same on my MI sights on my POF Predator rail on my Spike's Tactical AR .22LR upper.

I *may* have to do the same on my latest Troy stnd. AR height BUIS on my PDW mini upper.  Haven't shot it enough to know yet (long story).

I sight my irons in at 25M (about 82 feet) and that very well may be the problem.  I've been doing this (and probably doing it incorrectly for these types of irons) ever since I bought my first Bushmaster AR-15 with the standard A2 style sights.  IIRC, after zeroing for 25M, if you clicked the rear elevation drum down once, it put you at the 300M zero. Since Troys don't have this feature.....that's entirely possible as to why I'm having to shorten these sights now that I think about it.

All that said, the other reason I sight my irons in at this distance is: for SBRs with short bbls....up to 100 yards, this method seems to work fine.  I don't get to shoot much past that distance with them and since my SBRs are HD guns, I'll never shoot anywhere close to that distance in a HD situation. 

HTH,
Sean

***EDITED TO EXPLAIN WHAT I DID TO MODIFY MINE****

Drilling to make the plunger spring drop down farther will NOT work.  The stubbies/Micros are too short.  The bit would pop out the bottom of the shelf built into the front post.

I just sanded the plunger down 1/16" (with an air sander and cleaned it up with a file slightly), then clipped 2.5 coils off the spring.

The plunger started out at 7/32"....it's now 5/32" (those measurements don't include the "nipple").

[Lizardman]

same as SeanK.  Had to cut 2 coils off spring and file down the plunger with my dremmel by about 1/3 off the original length.

was shooting about 6 inches low at 50 meters with the original setup.

[Candidus]

That is exactly where I am at.

With the front post cranked all the way down my groups are about 4 - 5" low at 50 yards. I am adjusting and seem to do pretty good at longer distances out to and past 100 yards. It is just the up close stuff that is way off. I haven't modified mine yet but I let Troy know about the issue. They should allow more downward adustment to raise shot groups. 

[Cid1911]

This is interesting. At first I assumed that most people would not have to modify the front sight for the XCR since it's a good deal lower already than a standard height sights, but so far it's even odds on whether modification is required. Of course, only 6 people have voted thus far...

[Candidus]

What's more confusing is that I had standard Troys mounted before and was able to adjust low enough. I am like  I just wanted the "Mircro" sights because the lower the profile the better as far as I'm concerend.

I have only been out once with the new "Micro" sights. I will go out again before making my final assessment.

[Cid1911]

What's more confusing is that I had standard Troys mounted before and was able to adjust low enough. I am like  I just wanted the "Mircro" sights because the lower the profile the better as far as I'm concerend.

I have only been out once with the new "Micro" sights. I will go out again before making my final assessment.

Weird... Did you at least get a better cheek weld/sight picture with the low heights?

[Sean K.]

What's more confusing is that I had standard Troys mounted before and was able to adjust low enough. I am like  I just wanted the "Mircro" sights because the lower the profile the better as far as I'm concerend.

I have only been out once with the new "Micro" sights. I will go out again before making my final assessment.

Ya, I noticed the same thing with my stnd. Troys on one of my XCR uppers.  On my PDW, there were some other pressing issues so I didn't get to sight it in....but what I originally thought (that I'd have to modify the plunger and spring) I now think is incorrect.  I think there's enough adjustment to sight the stnd. height Troys on that upper as well.

Maybe it's got a deeper pocket for the plunger to go down in since the overall height of the front post is higher.
Sean

[tzoid]

  I hope this is not the case...I just bought the FDE Troy Micros and tried to BZO at 50 yards and the weather F'D me so
I'm going to try when the weathers better.

   Is the issue that the front post will not go low enough...ie , shooting high?
 I picked up a set of MBUIS and they zeroed in about 6 shots

   Feedback guys please

[Cid1911]

My buddy has a set that required no mods and at least several other on the forum have had no problems as you can see. I think the issue is that the front sight detent will not depress enough for those that do have to mod them and/or the front sight post won't depress enough and must be filed down a bit. It doesn't sound like the mod is anything drastic if you do have problems. Even if you do have to mod them, they're still the best option for the XCR IMO.

[Sean K.]

  I hope this is not the case...I just bought the FDE Troy Micros and tried to BZO at 50 yards and the weather F'D me so
I'm going to try when the weathers better.

   Is the issue that the front post will not go low enough...ie , shooting high?
 I picked up a set of MBUIS and they zeroed in about 6 shots

   Feedback guys please

Yes....shooting too high at 25M.

Funny thing: I zero'd my standard height Troy's on my XCR mini upper.....I actually had to bring the post UP to get it zero'd.  No modification was necessary.   Beats me.....unless there's minute differences in the Troy sights....that's the only thing I can come up with.

Sean

[dont_tread_on_me]

  If the front post won't go low enough,wouldn't it be shooting to high?

[LurpyGeek]

  If the front post won't go low enough,wouldn't it be shooting to high?

?  Not by my logic.  The higher the front post, the lower the muzzle direction.  Pushing the front post lower means a higher muzzle direction.

[Cid1911]

  If the front post won't go low enough,wouldn't it be shooting to high?

?  Not by my logic.  The higher the front post, the lower the muzzle direction.  Pushing the front post lower means a higher muzzle direction.

That's how it's always worked for me. The lower the post, the higher the P.O.I.

[Lizardman]

exactly.

For those who need the post to drop further, but it won't, should be shooting low.  My POI was about 6 inches below my point of aim at 50 meters. 

[Sean K.]

  If the front post won't go low enough,wouldn't it be shooting to high?

My fault....I don't think I was very clear in my earlier response about which set was shooting high/low. 

[dont_tread_on_me]

 Yea when I read that I hadn't slept all day so I wanted to make sure my thinking was clear.When I first bought my XCR I got a set of backup irons for it.What I didn't know at the time was that the front sight I bought was for a gas block on an AR,not for the same plane.The gas block on an AR does not match the rail height,it's always lower....sooooo In order for the front and rear sight to work together for a gas block mounted front sight,it naturally would have to be taller than a same plane mounted front sight.So when you put that on the same plane as the rear sight (like the XCR) it's way too high.When I went to zero that setup it was shooting like 22 inches low at 25 yards.Even after grinding the post down I would only get about 18 inches below the bull.
  To help you understand,lets say the gun is clamped into a benchrest not able to move and the bore is perfectly level and when you look down the sights the front post is where it need to be (good sight picture),but when you fire the gun,it hits low.So you lower the post,with the gun still clamped in the benchrest,obviously if you fire again,not changing where the bore is "looking" it will still be low,but when you look down the sights now ,you'll no longer have a perfect sight picture,but the front post will be too low in the rear aperture,depending of course how much you lower the front post as to how much you notice this,but lets say you move it a lot and can notice a difference.
  So if your front post is now at the bottom of rear aperture,your going to have to move the buttstock down in order to center that post again.When you do that your in effect moving where the bore is looking,which would be up in this case.So if you were shooting low,you lower the post,which causes you to lower the buttstock in order to get a proper sight picture.I hope that makes sense.

[Sean K.]

Yea when I read that I hadn't slept all day so I wanted to make sure my thinking was clear.When I first bought my XCR I got a set of backup irons for it.What I didn't know at the time was that the front sight I bought was for a gas block on an AR,not for the same plane.The gas block on an AR does not match the rail height,it's always lower....sooooo In order for the front and rear sight to work together for a gas block mounted front sight,it naturally would have to be taller than a same plane mounted front sight.So when you put that on the same plane as the rear sight (like the XCR) it's way too high.When I went to zero that setup it was shooting like 22 inches low at 25 yards.Even after grinding the post down I would only get about 18 inches below the bull.
  To help you understand,lets say the gun is clamped into a benchrest not able to move and the bore is perfectly level and when you look down the sights the front post is where it need to be (good sight picture),but when you fire the gun,it hits low.So you lower the post,with the gun still clamped in the benchrest,obviously if you fire again,not changing where the bore is "looking" it will still be low,but when you look down the sights now ,you'll no longer have a perfect sight picture,but the front post will be too low in the rear aperture,depending of course how much you lower the front post as to how much you notice this,but lets say you move it a lot and can notice a difference.
  So if your front post is now at the bottom of rear aperture,your going to have to move the buttstock down in order to center that post again.When you do that your in effect moving where the bore is looking,which would be up in this case.So if you were shooting low,you lower the post,which causes you to lower the buttstock in order to get a proper sight picture.I hope that makes sense.

My problem is my memory sucks.   I can't remember what I had to do now to make both sets work and have the bullets hit where I was aiming.  All I know for certain is I shortened the plunger/spring on the stubbies and didn't have to do anything to the std. height Troys (except spin the front post up).

IIRC, (and I can't swear to this b/c like I said, I have the brain of a gnat)....with the stubbies  (before the mod), at 25M I was shooting a little bit low (like maybe an inch or 2).....the shooting low part is where I'm not 100% positive.  I think it was low....but I'm not positive I wasn't shooting high.  Once I modded the stubbies, I was able to zero by threading the post DOWN into the front sight.  That part I'm sure about.

On the std. height troys.....I started shooting at 25M with the front post bottomed out in the front sight.  I was shooting way high.....like 8" or so.  I threaded the front post UP this time and zero'd at 25M without any actual modification to the sight.  This one I'm positive about b/c I zero'd it last week and my pea brain can remember back that far.

HTH explain it,
Sean

[tzoid]

  I bought a set of the Troy Micro's in FDE for my Pencil barrel XCR 5.56 and Zeroed them at 50 yards in 12 rounds. 

       They were perfect windage wise and I only had to adjust elevation 8 clicks. 

  I do have a question about the person that posted he zeroed his XCR at 200 Yards , Why would you do that and man you must have good eyes.
 Isn't a 50 Yard zero go for 200 yards anyway?

[dont_tread_on_me]

On the std. height troys.....I started shooting at 25M with the front post bottomed out in the front sight.  I was shooting way high.....like 8" or so.  I threaded the front post UP this time and zero'd at 25M without any actual modification to the sight.  This one I'm positive about b/c I zero'd it last week and my pea brain can remember back that far. 

  Sean I don't know what to tell you about that,and I don't doubt your word,but I'm absolutely certain that lowering the front post should raise you point of impact,that's just weird.

I do have a question about the person that posted he zeroed his XCR at 200 Yards , Why would you do that and man you must have good eyes.
 Isn't a 50 Yard zero go for 200 yards anyway?

  That all depends on the load your using and at what range you want your actual zero to be.Shooting at 25,35 or 50 will get you close at certain long range distances (again depending on your actual load and muzzle velocity).So even though say a 25 yard zero will get you a 300 yard battle sight zero,you should always check actual impact at 300 to make sure,and to fine tune it.

[DSM]

  I do have a question about the person that posted he zeroed his XCR at 200 Yards , Why would you do that and man you must have good eyes.
 Isn't a 50 Yard zero go for 200 yards anyway?

My T1 was already zeroed at 200yds so before I left the house I boresighted the new irons off of it.  Then it was just a matter of small tweaks from there.  My wife helped me by spotting the rounds on the steel at that range so it went a bit faster than normal.  Not good eyes, just good enough to see the front sight post!

I usually start zeroing something new at 25 or 50 but I'll always check at the full distance I want them to be set on just to give me a warm fuzzy that they are where they need to be.  Usually at most it's only been a couple clicks here or there.  With a shorter barrel it's something I like to check out because shorter barrels do screwy things to external ballistics a lot sooner than longer ones--spin drift, stability, etc, and the higher sight over bore of the XCR changes things a little too.

[tzoid]

  I do the same thing.... 3 rounds at 25 yards adjust to Bull then move to 50 yards, verify BZO.

       Thank goodness for EoTech's and Aimpoints 

   

[Sean K.]

On the std. height troys.....I started shooting at 25M with the front post bottomed out in the front sight.  I was shooting way high.....like 8" or so.  I threaded the front post UP this time and zero'd at 25M without any actual modification to the sight.  This one I'm positive about b/c I zero'd it last week and my pea brain can remember back that far. 

  Sean I don't know what to tell you about that,and I don't doubt your word,but I'm absolutely certain that lowering the front post should raise you point of impact,that's just weird.

But that IS what happened with the stubbies.  When I modded the stubbies to be able to lower the front post farther, it DID raise the point of impact.

You quoted the part about my stnd. height troys where I was shooting high, so I did the opposite (threaded the front post DOWN) and got it on target.

One of us is all screwed up.....I'm betting it's me.   All I know is: now my bullets go where the sights are lined up and I guess that's all that really matters.

Sean

[dont_tread_on_me]

But that IS what happened with the stubbies.  When I modded the stubbies to be able to lower the front post farther, it DID raise the point of impact.

You quoted the part about my stnd. height troys where I was shooting high, so I did the opposite (threaded the front post DOWN) and got it on target.

One of us is all screwed up.....I'm betting it's me.   All I know is: now my bullets go where the sights are lined up and I guess that's all that really matters.

Sean

  Ok let me see if we can get on the same page.You mean that on the stubbies when you lowered the front post by screwing it down(clockwise),raised your point of impact? It wouldn't go low enough to raise you POI,so you took off material so that it could go lower? That makes sense to me and what I think should have happened.
  I think I misunderstood what you were saying about the standard sights.Now that I re-read it,I think you meant that you had the opposite problem (shooting high instead of low) so you raised the front post to get the correct POI,which again would be the correct direction to get the desired change of POI.I thought you meant you had move your front sight post in the exact opposite direction than the stubbies in order to change you POI.This was my mistake entirely.I must have been reading to fast or half asleep.My apologies.